There is a particular kind of homesickness that has nothing to do with people or furniture. It shows up a few weeks after a move, in the gut, as a vague unsettledness that nobody quite wants to name. New water. New air. New bread from a new bakery. We tend to blame stress, or jet lag, or the takeout containers still stacked in a box marked “kitchen.” What we rarely blame is the possibility that we ourselves have changed, at a scale too small to see, because the ecosystem living inside us has started renegotiating its membership with the ecosystem outside our door.

That renegotiation is real, and it happens faster than most people assume. The human microbiome, the collection of bacteria, fungi, viruses and archaea that outnumber our own cells, is not a fixed inheritance handed down like eye color. It is mostly built, continuously, out of exposure. And when exposure changes, so does the community living in and on us, sometimes within days.

How much of it is actually ours

For a long time the working assumption was that microbiome composition, like most biology, was substantially a matter of genetics. Twin studies complicated that picture rather than confirming it. Researchers comparing identical and fraternal twins have found that certain individual microbial taxa are modestly heritable, and a handful, such as the bacterial family Christensenellaceae, show up reliably across cohorts. But the more striking finding, published in Nature by Rothschild and colleagues in 2018, was that genetic ancestry barely predicts microbiome composition at all. People who are genetically unrelated but share a household converge on similar microbial communities, while genetically related people living apart do not. Environment, not lineage, was doing most of the sculpting.

A later and even larger analysis, published in Science by Grieneisen and colleagues in 2021 using a decades-long dataset of wild baboons, found something almost paradoxical: heritability of the microbiome is nearly universal, in the sense that a small genetic signature can be detected almost everywhere researchers look, but the actual size of that genetic contribution is tiny, and it depends heavily on the surrounding ecology and diet. In other words, genes leave a faint fingerprint on which microbes are allowed to flourish, but the environment decides who actually shows up to the party.

This matters enormously for anyone who has ever moved. If the microbiome were mostly written into our DNA, a relocation would barely touch it. Because it is instead assembled largely from exposure, from soil, food, water, other bodies, pets, and the specific mix of organisms living in a particular house in a particular climate, a move is one of the more disruptive events a human microbiome can experience.

The first move any of us makes

Before we ever pack a box, we make the most consequential relocation of our microbial lives: birth. The infant gut, essentially sterile in utero, is seeded within hours by the birth canal or, in a cesarean delivery, by skin and hospital air instead. Breastfeeding, siblings, pets and rural versus urban living all continue shaping that early community for years. The now-famous 1989 observation by the epidemiologist David Strachan, that children with more older siblings had lower rates of hay fever, became the seed of what is known as the hygiene hypothesis, later refined by the immunologist Graham Rook into what he called the “old friends” hypothesis. The idea is not that dirt itself is protective, but that certain microorganisms which coevolved with humans over hundreds of thousands of years are required to properly calibrate the immune system’s regulatory machinery, the part of the body that is supposed to tell the difference between a real threat and a piece of pollen or peanut protein. Remove those organisms from early life, as sanitation, antibiotics, cesarean birth and smaller families have done across the industrialized world, and the immune system can end up undertrained, more prone to overreacting to harmless things.

That framework, built almost entirely around infancy, has quietly expanded in the last decade to include something researchers had not focused on nearly as much: what happens when a fully formed adult immune system and its resident microbiome are relocated wholesale into a new environment.

What actually changes when you move

The clearest evidence comes from immigration research, because immigration is essentially a natural experiment in environmental replacement. A landmark 2018 study in Cell, led by Pajau Vangay and Dan Knights at the University of Minnesota, tracked Hmong and Karen refugees relocating from Thailand to the United States. The results were fast and dramatic: within the first months after arrival, participants began losing native gut bacteria, particularly fiber-fermenting Prevotella species, and acquiring Bacteroides strains typical of American guts. The loss of diversity increased the longer someone had lived in the United States, worsened across generations, and was linked to rising rates of obesity in the same population, a pattern the researchers described as an immediate and ongoing “Westernization” of the gut.

A parallel line of research on the Hispanic Community Health Study/Study of Latinos, published in Genome Biology by Kaplan and colleagues, found much the same thing in a very different population: greater time spent in the United States tracked with reduced microbial diversity and a decline in the bacterial genes responsible for breaking down dietary fiber. A related analysis of the same cohort, published by Wang and colleagues in 2021, again tied U.S. residency length to shifts in specific taxa associated with a more processed, lower-fiber diet.

It is tempting to file all of this under diet alone, since new arrivals in a country are also eating differently. But researchers keep finding that diet does not fully explain the pattern. A 2025 review in Frontiers in Clinical Diabetes and Healthcare, by Fasipe and Laher, lays out the fuller mechanism: migration disrupts circadian rhythm through new work schedules and light exposure, introduces chronic psychosocial stress that activates the body’s cortisol and inflammatory signaling, and reduces physical activity, all of which act on the gut microbiome independently of what shows up on the plate. Moving, in other words, is metabolically and immunologically disruptive in ways that have very little to do with willpower or cuisine.

Altitude offers a cleaner, less confounded version of the same story, because the food supply can stay relatively constant even as the environment changes drastically. A registered clinical trial tracking people relocating to high-altitude Gangcha County in China found measurable shifts in gut bacterial composition within six months of the move, with further changes at twelve months, and partial reversal a month after returning home. The microbiome, it turns out, is listening to elevation, oxygen tension and temperature, not only to the dinner table.

There is a quieter variable in all of this that has received far less research attention than diet or climate: the actual chemical load a person is breathing, drinking and eating, which can shift substantially with an address change and which interacts with the microbiome in ways researchers are only beginning to map. Pesticide exposure is the clearest example. A 2022 biomonitoring study of British twins, published in Environmental Health, found detectable pyrethroid or organophosphate insecticide residues in the urine of every participant tested, with the specific pesticide mix and concentration varying by geographic location, by whether someone lived in a rural or urban area, and by local dietary habits, and higher residue levels were associated with measurable shifts in gut microbial composition and metabolic activity. A separate 2023 study of nearly seven thousand people in the Dutch Microbiome Project found that occupational and regional pesticide exposure tracked with distinct gut microbiome signatures, independent of the general “geography effect” already known to shape the microbiome. Because agricultural practices, permitted pesticide classes, and spraying intensity all vary enormously from one country, state, or even county to the next, a move from a region with heavy orchard or row-crop spraying to one with different agricultural chemistry, or from conventional to organic-leaning food supply chains, plausibly changes this chemical exposure quite a bit more than most people moving house would ever think to ask about.

Drinking water tells a similar story. Municipal water systems disinfect with different agents and different intensities depending on the region, chlorine in some places, chloramine in others, and the resulting disinfection byproducts vary with local water chemistry and even the season. A 2024 randomized controlled trial in infants found that chlorinated tap water increased the carriage of antibiotic-resistance genes in the developing gut microbiome compared with dechlorinated water, and laboratory studies in mice have found that chlorinated drinking water measurably reduces gut microbial diversity, an effect that appears at least partly reversible once exposure stops. None of this means tap water is dangerous; disinfection is what makes water safe to drink in the first place. But it does mean that the water someone showers in and drinks every day is not chemically neutral from one town to the next, and a household that switches from a well to municipal chloraminated water, or from one city’s water utility to another’s, is quietly changing one more input the gut community has to adapt to.

Air itself varies by exactly this kind of underappreciated chemistry. Fine particulate matter, PM2.5, is not a single uniform pollutant; its composition, sulfates in one region, diesel soot in another, agricultural ammonia or wildfire smoke in a third, differs by location and by the dominant local emission sources, and animal studies have repeatedly found that inhaled particulate matter reaches and measurably disrupts the gut microbiome as well as the lungs, reducing microbial richness and altering short-chain fatty acid production. A study of people working an open-air market during a smog event found dozens of new bacterial genera appearing in the human pharynx immediately after heavy PM2.5 exposure, genera traced back to soil, sewage, and other environmental sources that the smog itself appeared to be carrying. Moving from a region with one dominant pollution signature, coastal, agricultural, industrial, wildfire-prone, to a region with an entirely different one is, in this light, a kind of inhaled chemical exposure change that nobody packs into a moving box but that the airway and gut microbiome experience directly.

Taken together, pesticide residue, water disinfection chemistry and airborne particulate composition form a background chemical exposure profile that shifts with almost every relocation, largely independent of the biological exposures already discussed, and current research has only begun to disentangle how much of the microbiome disruption attributed to “moving” is really attributable to the microbes in a new place versus the specific chemical cocktail traveling through the water, food and air of that place.

The house has its own microbiome, too

Here is where the fungal side of the story, often left out of gut-microbiome coverage entirely, becomes essential. Every home has a resident mycobiome, a community of molds and yeasts living in dust, on surfaces and in the air, and it varies enormously by geography. A 2020 analysis of more than three thousand French dwellings found that indoor fungal and bacterial allergen levels tracked climate and land use across the country in consistent geographic gradients, with some organisms increasing from northeast to southwest and others running in the opposite direction. A continental-scale study of hotel rooms across nineteen European and Asian countries, published in mSystems, found that local climate and land use, more than building design, predicted the fungal and bacterial makeup of the dust accumulating over doorframes. Global surveys of outdoor settled dust across thirty-three countries have found the same climate-driven fingerprint at planetary scale.

None of this is trivial to the humans living inside those buildings. A 2022 study of French homes found that low-diversity indoor mycobiomes in early life were associated with a higher later risk of asthma, while children exposed to richer, more diverse fungal communities in the first years of life showed some protection against allergic disease. Perhaps the most vivid demonstration of this comes from a genetically similar but environmentally distinct pair of American farming communities, published in the New England Journal of Medicine in 2016. Amish children in Indiana, who live on small traditional dairy farms in daily contact with animals, had roughly one fifth the rate of asthma of Hutterite children in South Dakota, who live on large, mechanized communal farms with far less direct animal contact. Dust from Amish homes carried nearly seven times the microbial endotoxin of Hutterite dust, and when researchers gave mice extracts of that Amish house dust, it protected them from experimental asthma; Hutterite dust did not. Genetics could not explain the gap. The microbial content of the house could.

Move a person, or a child, from one of these microbial regimes into another, and you are not simply changing their scenery. You are changing the invisible cloud of organisms that trains their immune system every single day.

This raises a specific question worth answering directly: does the style of a modern, Westernized home actually produce more fungal presence than a traditional one, or less? The honest answer is that it depends on which measure you look at, and the two findings pull in opposite directions in an interesting way. On overall diversity, the more insulated and mechanically sealed a home is from the outdoors, the fewer environmental microbes it tends to receive. A widely cited study of hospital patient rooms, published in The ISME Journal, found that mechanically ventilated rooms carried significantly less diverse airborne bacterial communities than window-ventilated rooms breathing in outside air, and a separate study comparing homes across an urbanization gradient in South America found that increasingly urban, increasingly sealed dwellings grew more isolated from outdoor microbial input the more “developed” their construction became. By that measure, tightly built modern homes are actually microbially thinner, not richer, which tracks with the broader finding that Western populations carry less diverse gut and environmental microbiomes than people living in more traditional, open-air dwellings.

But total fungal load, as opposed to diversity, can run the other way, for reasons that have more to do with materials science than biology. Fungi need three things to establish themselves on a surface: spores, which are essentially always present in both indoor and outdoor air, a food source, and moisture. The building materials that define modern Western construction, drywall in particular, along with its paper facing, adhesives, and any accumulated dust, are an unusually good food source for common indoor molds, considerably more digestible to fungi than the stone, lime plaster, or solid masonry that characterized older or more traditional building styles. Layer onto that the airtightness that modern energy-efficient construction prizes, and you get a second problem: a tightly sealed building envelope is excellent at trapping heat and cooling costs, but if its mechanical ventilation is not carefully balanced, it is equally good at trapping the water vapor generated by ordinary showering, cooking, and breathing, which then condenses on the inside of a wall assembly precisely where it cannot easily escape. Building science literature is fairly blunt about this trade-off: airtightness without designed ventilation does not eliminate moisture, it relocates it, often into a wall cavity lined with the very material fungi prefer to eat. The result is a real, if narrower, phenomenon in which a newer, tighter, drywall-heavy home can develop a more concentrated fungal problem in a specific damp location, even while the home as a whole receives less overall microbial diversity from the outside world than a drafty older building or a traditional open-air dwelling would. Thinner exposure and, under the wrong moisture conditions, a hotter localized fungal load are not contradictory; they are simply measuring different things.

Where new intolerances actually come from

This is the part of the conversation people living through a move most want an answer to: why does a food that never bothered you suddenly cause trouble in a new city, a new climate, a new country?

Some of the mechanism is now well understood rather than speculative. Pollen-food allergy syndrome, sometimes called oral allergy syndrome, is a genuinely established phenomenon in which a person who develops a new sensitivity to local pollen, because they have moved somewhere with different trees, grasses or weeds, begins reacting to foods that share structurally similar proteins with that pollen. Birch pollen sensitization, for instance, is well documented to cross-react with apples, hazelnuts, celery and stone fruits, largely because those foods contain a protein that closely resembles the major birch allergen. Clinical reviews note that this pattern varies by region: reactions linked to birch-related proteins are far more common in places where birch trees are part of the landscape than in birch-free regions such as much of Spain, where the same fruits are tolerated differently or trigger different cross-reactive patterns entirely. A person who moves from a birch-sparse region into a birch-heavy one, develops a new pollen sensitivity over a season or two, and then finds themselves suddenly unable to eat a raw apple, is not imagining a new intolerance. They have acquired one, through a documented immunological pathway, simply by changing address.

The gut side of the story is more indirect but converges on the same theme. As Prevotella-rich, fiber-fermenting communities are displaced by Bacteroides-dominant, Western-style ones after a move, researchers have documented a corresponding decline in the bacterial machinery that breaks down complex plant fibers. A gut that has quietly lost the specific enzymes needed to ferment a food is a gut more likely to react to that food with bloating, gas or discomfort, an outcome that looks and feels like a new intolerance even though nothing about the food itself has changed. Separately, the hygiene and old-friends research on food allergy specifically, reviewed extensively in a 2019 National Academies report and in ongoing work on gut dysbiosis and food allergy risk, points to a shared mechanism: a less diverse, disrupted microbial community appears to precede and possibly enable the immune system’s shift toward treating a harmless food protein as a threat. None of this has been proven to explain any single person’s new reaction to shellfish or dairy after a move. But the pieces, taken together, describe a biologically coherent story: change the input, and the output, in the form of what the immune system tolerates, can change with it.

The more speculative territory

Here the science gets genuinely more hypothesis than fact, and it deserves to be labeled that plainly. The gut-brain axis, the bidirectional communication network linking gut microbes to the central nervous system through the vagus nerve, immune signaling and metabolites like short-chain fatty acids, is one of the most active areas in microbiome science, and much of the foundational evidence still comes from mice rather than people. Germ-free mice, raised with no microbiome at all, show altered stress hormone responses and different behavior in anxiety-related tests. Fecal transplants from anxious or depressed human donors into rodents have, in several studies, transferred some of the corresponding behavioral traits to the animals receiving them. A 2025 study, still preliminary, found that mice bred to have naturally higher or lower innate anxiety carried correspondingly distinct gut microbial communities, and that transplanting a “high anxiety” microbiome into a calmer mouse shifted its behavior toward anxiety, along with measurable activity changes in the brain’s fear circuitry.

Whether any of this scales up to something as complex as human personality, mood or temperament shifting after a relocation remains genuinely unknown, and researchers in the field are careful to say so. It is an intriguing, testable hypothesis, not a settled fact, that a person who becomes more anxious, more low-energy, or simply “not themselves” for a few months after a big move might be experiencing something partly downstream of a disrupted gut community rather than purely psychological adjustment. It is equally plausible that the causation runs the other way, with the stress of the move itself altering the microbiome, which is well documented, rather than the microbiome altering the mood. Anyone drawing a straight line from a new zip code to a new personality is getting ahead of the data. But the biological plumbing for that connection to exist is no longer imaginary. It is being actively mapped.

When the new territory is itself unwell

There is a darker version of this whole story that deserves its own chapter, because it is not about a healthy microbiome being traded for a different healthy one. It is about what happens when the environment a person moves into, whether that is a home, a building or a region, is not colonized by a rich, balanced community of organisms at all, but by something thinner, more aggressive, or simply hostile. A move is not always a lateral transfer between two functioning ecosystems. Sometimes it is a move into a vacuum, and vacuums get filled by whatever is strong enough to fill them.

Inside the body, this phenomenon has a name: colonization resistance. A healthy, diverse gut microbiome does not merely coexist peacefully; it actively defends its territory. Resident bacteria compete for nutrients and physical space, produce antimicrobial compounds and short-chain fatty acids that keep the gut environment inhospitable to invaders, and help maintain the low-oxygen conditions that most opportunistic pathogens cannot tolerate. A landmark line of research going back to the 1950s, and elaborated in decades of subsequent work, has shown what happens when that resistance breaks down. Antibiotic treatment is the clearest trigger: broad-spectrum antibiotics do not simply kill a target pathogen, they collapse the surrounding ecosystem, and organisms like Clostridioides difficile, Salmonella, and antibiotic-resistant Enterobacteriaceae expand rapidly into the newly emptied niche, in some cases converting what would have been an unremarkable exposure into a serious, difficult-to-treat infection. The point that matters for anyone thinking about environment and health is this: a “bad” bacterium is very often not a foreign invader at all. It is frequently already present in vanishingly small numbers, quietly waiting for its competitors to disappear.

The same dynamic exists outside the body, in the specific physical spaces we occupy, and it is where the fungal and bacterial threads of this piece meet something closer to public health hazard than lifestyle trivia. Modern plumbing, in particular, has created an entirely new ecological niche that did not exist for most of human history: long runs of metal and plastic pipe, warm stagnant water, and low-flow conditions, all of which happen to be ideal for a specific cast of organisms known as opportunistic premise plumbing pathogens. Researchers who study these systems have documented that Legionella pneumophila, Pseudomonas aeruginosa, Mycobacterium avium, Acinetobacter baumannii and Stenotrophomonas maltophilia are essentially native residents of building water systems, not contaminants that occasionally intrude. They favor exactly the conditions that many buildings, especially newer, more complex, or infrequently used ones, provide by default: warm water sitting still, minimal disinfectant residual, and biofilms lining the interior of pipes. A widely cited 2020 review in Microorganisms by Falkinham describes these organisms as sharing a common survival strategy, forming biofilms, tolerating disinfectants far better than free-floating bacteria, and thriving on the low nutrient levels typical of treated water, which is precisely what lets them persist even in systems that appear, by ordinary standards, to be clean. A 2025 Australian survey of hospital and residential water systems found Pseudomonas aeruginosa in about forty percent of samples and Legionella species in roughly a quarter, with residential buildings showing higher prevalence than hospitals in several categories, a finding that should complicate any assumption that a private home is automatically a safer microbial environment than an institutional one.

Water-damaged buildings add a second layer to this. It is well established that chronic moisture intrusion changes which fungi grow indoors, but researchers studying moisture-damaged materials have also found that these same damp environments regularly harbor free-living amoebae, organisms like Acanthamoeba and Naegleria, living alongside molds such as Aspergillus versicolor and Chaetomium. These amoebae are not incidental. Several species are capable of directly infecting humans, and more importantly, they are known to serve as a kind of biological shelter for bacteria like Legionella, protecting them from disinfectants and allowing them to replicate inside the amoeba itself before being released back into the environment in a hardier, more infectious form. A damp, poorly ventilated building, in other words, is not simply growing “mold.” It can be running a small, self-sustaining incubator for organisms that use fungi and protozoa as stepping stones toward human infection.

This is the piece that connects most directly back to the immune system, and to why “the body will just handle it” is not a reliable assumption. Once these organisms establish themselves as a biofilm, whether in a building’s plumbing, in a chronic wound, or in the airway of someone with an underlying lung condition, they become dramatically harder for the immune system to clear than the same organism floating freely would be. A biofilm is a physical structure: bacteria embedded in a self-produced matrix that acts as a shield, both against antibiotics and against the immune system’s own weapons. Research summarized in a 2025 review in npj Biofilms and Microbiomes describes how neutrophils, the immune system’s first responders, arrive at a biofilm and unleash extracellular traps and reactive oxygen species meant to kill the bacteria, but the biofilm’s matrix blunts much of that attack, while the resulting inflammation damages the surrounding tissue anyway, producing a strange stalemate in which the body cannot clear the infection and cannot stop reacting to it either. Other reviews describe this as a kind of chronic miscoordination between the innate and adaptive immune systems, neither arm able to finish the job, sometimes for years. This is part of why conditions linked to biofilm-forming opportunists, chronic wounds, implant infections, recurrent Legionella exposure, cystic fibrosis lung infections, are notoriously resistant to a course of antibiotics and a period of rest. The organism is not simply present. It has built a fortress.

None of this is meant to induce alarm about ordinary living. Most people move through buildings with imperfect plumbing and imperfect air quality every day without incident, because a functioning immune system, adequate airflow, and reasonable water turnover keep these opportunists in check most of the time. But it does mean that “moving into a healthier environment” is not automatically true just because a new house looks clean or a new region looks scenic. A newly built or newly renovated home can have plumbing biofilms still establishing themselves, exactly the pattern documented in studies of new pipe material, where Legionella species were found to be among the earliest colonizers of freshly installed plumbing rather than a later contaminant. An older, damper building in a humid climate can be hosting a mixed fungal and amoebal community that a drier region simply does not support. And a person arriving into either kind of space with a gut microbiome already thinned by antibiotics, a recent illness, or the disruption of the move itself may be, at that exact moment, less equipped to hold the line against whatever is already colonizing the address they have just moved into.

What to make of all this

None of this argues against moving, obviously, nor does it suggest that a new home is something to fear biologically. Human beings have been relocating, migrating and resettling for as long as we have existed, and the microbiome’s flexibility is arguably a feature rather than a flaw, the same adaptability that let early humans colonize new continents and new diets. But it does argue for a little more patience with the body during a transition, and a little more curiosity about a new intolerance rather than an assumption that it must be permanent or purely psychosomatic. The gut that reacts to the water in a new city, the skin that breaks out in a new climate, the sudden inability to eat a raw peach after a move north, these are not necessarily signs of fragility. They may be closer to jet lag: a real, temporary, biologically explicable process of an old ecosystem meeting a new one and figuring out, cell by cell and microbe by microbe, how to live there.

Selected references and further reading

• Rothschild, D. et al. “Environment dominates over host genetics in shaping human gut microbiota.” Nature, 2018.

• Grieneisen, L. et al. “Gut microbiome heritability is nearly universal but environmentally contingent.” Science, 2021.

• Vangay, P., Johnson, A.J., Ward, T.L. et al. “US Immigration Westernizes the Human Gut Microbiome.” Cell, 2018.

• Kaplan, R.C. et al. “Gut microbiome composition in the Hispanic Community Health Study/Study of Latinos is shaped by geographic relocation, environmental factors, and obesity.” Genome Biology, 2019.

• Wang, Z. et al. “Microbial co-occurrence complicates associations of gut microbiome with US immigration, dietary intake and obesity.” Genome Biology, 2021.

• Fasipe, B. and Laher, I. “Obesity and metabolic disease in migrants: a role for the gut microbiome?” Frontiers in Clinical Diabetes and Healthcare, 2025.

• Clinical trial NCT05901896, “Temporal Changes in the Gut Microbiota Before and After Migrating to High Altitude.”

• Fouquier, J. et al. “Indoor Microbiome: Quantification of Exposure and Association with Geographical Location, Meteorological Factors, and Land Use in France.” Microorganisms, 2020.

• Continental-scale hotel dust study, mSystems, 2020.

• Season, Vegetation Proximity and Building Age Shape the Indoor Fungal Communities’ Composition at City-Scale, PMC, 2022 (mycobiome diversity and asthma risk).

• Mesnage, R. et al. “Impacts of dietary exposure to pesticides on faecal microbiome metabolism in adult twins.” Environmental Health, 2022.

• “Impact of occupational pesticide exposure on the human gut microbiome,” Dutch Microbiome Project/Lifelines Study, Frontiers in Microbiology, 2023.

• “Chlorinated Drinking Water Exposure Enriches Antimicrobial Resistance Pathways in the Infant Gut Microbiome: A Randomized Trial,” medRxiv, 2024.

• “Exposure to chlorinated drinking water alters the murine fecal microbiota,” PMC, 2024.

• “High-Level PM2.5/PM10 Exposure Is Associated With Alterations in the Human Pharyngeal Microbiota Composition,” PMC, 2019.

• “The effect of real-ambient PM2.5 exposure on the lung and gut microbiomes and the regulation of Nrf2,” Environmental Toxicology and Pharmacology, 2023.

• Kembel, S.T. et al. “Architectural design influences the diversity and structure of the built environment microbiome.” The ISME Journal, 2012.

• Ruiz-Calderon, J.F. et al. “Walls talk: Microbial biogeography of homes spanning urbanization.” Science Advances, 2016.

• “The changing microbial landscape of Western society: Diet, dwellings and discordance.” Evolution, Medicine, and Public Health (ScienceDirect), 2016.

• “The potential importance of the built-environment microbiome and its impact on human health.” PNAS, 2024.

• Building Science and Mold, International Association of Certified Indoor Air Consultants; WBDG “Mold and Moisture Dynamics” and “Indoor Air Quality and Mold Prevention of the Building Envelope.”

• Stein, M.M. et al. “Innate Immunity and Asthma Risk in Amish and Hutterite Farm Children.” New England Journal of Medicine, 2016.

• Strachan, D.P. “Hay fever, hygiene, and household size.” BMJ, 1989.

• Rook, G.A.W. “The old friends hypothesis: evolution, immunoregulation and essential microbial inputs.” Frontiers in Allergy, 2023.

• National Academies of Sciences, Engineering, and Medicine. Finding a Path to Safety in Food Allergy, 2017 (microbial hypotheses chapter).

• Pathogenesis of pollen-food allergy syndrome (oral allergy syndrome), UpToDate clinical review; comprehensive PFAS reviews in Nutrients (2026) and ScienceDirect (2024).

• Gut microbiota regulates innate anxiety through neural activity of medial prefrontal cortex in male mice, PMC, 2025.

• Margolis, K.G., Cryan, J.F., Mayer, E.A. “The microbiota-gut-brain axis: from motility to mood.” Gastroenterology, 2021.

• Khan, I. et al. “Mechanism of the Gut Microbiota Colonization Resistance and Enteric Pathogen Infection.” Frontiers in Cellular and Infection Microbiology, 2021.

• Intestinal colonization resistance in the context of environmental, host, and microbial determinants. Cell Host & Microbe, 2024.

• Falkinham, J.O. “Living with Legionella and Other Waterborne Pathogens.” Microorganisms, 2020.

• Opportunistic premise plumbing pathogens in Australian hospital and residential water systems. Frontiers in Microbiology, 2025.

• Dynamics of drinking water biofilm formation associated with Legionella spp. colonization. npj Biofilms and Microbiomes, 2024.

• Amoebae and other protozoa in material samples from moisture-damaged buildings. Science of the Total Environment (ScienceDirect), 2004.

• Immune system dynamics in response to Pseudomonas aeruginosa biofilms. npj Biofilms and Microbiomes, 2025.

• Chronic biofilm-based infections: skewing of the immune response. Pathogens and Disease, 2018.

This piece was written as an editorial synthesis of published, peer-reviewed research for The Location Effect. Sections on mood, personality and the gut-brain axis are explicitly framed as active, unresolved areas of hypothesis rather than established conclusions.

A few nights ago I dreamed I was back in my grandmother’s garden, the one place that held so much of my childhood in one small plot of land. My father was there with me, which felt like a real gift, to see him again even if only in my mind’s eye. It felt real, like old times, full of my dad’s teachings. Before the left us, taken quickly and cruelly by pancreatic cancer, we’d asked him to find a way o visit and continue to teach us, if his consciousness continue to exist in some form “on that another side”.

A neighbor of ours, who was like a little sister to me and for whom my dad was something like an uncle through her whole childhood, had a dream right after he died and made a point of telling us about it. She saw him holding mushrooms, and later, a bottle of spoiled milk. I found myself wondering if he was pointing us toward a fungal thread in his own cancer. There’s a small but real body of research looking at whether antifungal compounds like ketoconazole might interact with tumor growth, though it’s early science, far from settled, and nothing anyone should read as a treatment claim.

Back in my own dream, part of the garden had become water, rimmed with rocks and river plants. In it was a fish, black-skinned, unlike anything I’d seen. I asked my father if it was safe to eat. He said, I don’t know. That answer stopped me. He had been a fisherman among other things, one of the ways our family got through the scarcity of communism, and he almost never didn’t have an opinion about what came out of the water. Then he pointed me toward mounds of shells, clams, oysters, a few scallops, and I said we could eat those instead. That’s when he showed me the worms moving through them. I came out of the dream with the feeling that none of it, the fish or the shellfish, was actually safe to eat. Then I noticed dark red mushrooms growing all over the garden, the same image returning. I don’t know if that means anything. Maybe it’s just my mind circling back to mycology, which has quietly become a thread running through so much of my own work. But I like to imagine, in the loose, unprovable way you’re allowed to when you’re grieving, that the mushrooms were trying to tell me something too.

I told my sister about the dream the next morning, the way you tell someone a dream because it won’t let go of you. I almost didn’t write about it here. It felt too private, too much like reading tea leaves. Then a few days later, a study crossed my feed about black lesions on catfish in New England lakes, and I couldn’t shake the eerie coincidence.

Here’s what the study actually found, and why I think it matters far beyond the fish.

The catfish with the black spots

Researchers at the University of Vermont, publishing in Nature, have identified a transmissible cancer in brown bullhead catfish living in Lake Memphremagog, on the Vermont-Quebec border, and in a growing list of other lakes across New England and Canada. The lesions were first noticed by anglers back in 2012. By 2014, close to a third of the lake’s bullheads carried them.

The scientists initially suspected a virus or a pollutant-linked skin condition, since brown bullheads are considered indicator species for water quality. What they found instead was melanoma, a skin cancer normally associated with sun exposure, in a bottom-dwelling, scaleless fish that spends its life along dark lake sediment. That mismatch alone should tell you something: whatever is driving this, the sun has nothing to do with it. The fish that get it live where the sun doesn’t reach.

Whole-genome sequencing turned up something stranger still. The tumor cells across different fish were more genetically similar to each other than to the fish they were living in, the signature of a cancer that spreads cell to cell, like a parasite, rather than arising independently in each animal. This makes it only the fourth transmissible cancer ever documented in any species, after the facial tumors wiping through Tasmanian devil populations, a venereal tumor in dogs, and leukemia-like cancers in shellfish, and the first ever found in a freshwater fish.

The researchers suspect it spreads during spawning, when bullheads cluster in shallow water and make close physical contact, or through the sediment they burrow in. They’ve now traced the disease into Maine, New Hampshire, and New Brunswick, and they’ve found a possible historical fingerprint in Henry David Thoreau’s own journals. In 1852, on the Concord River in Massachusetts, he described a catfish with a black spot on its fin, and six years later a fish with what he called an inky black leprosy across half its head. Massachusetts, it turns out, may be where this disease was first written down.

Why arsenic doesn’t fully answer it

The study’s authors did find elevated arsenic in the tumor cells, and the geographic spread of the disease roughly tracks with naturally high arsenic soils in Vermont’s Northeast Kingdom and up through Maine. Arsenic is a real, well-documented carcinogen, and I don’t think the researchers are wrong to flag it.

But arsenic has been sitting in that bedrock for thousands of years. Thoreau’s fish were swimming in the same watershed in 1852. If arsenic alone explained this, we’d expect to have seen widespread outbreaks long before 2012. Something changed in the last few decades that didn’t exist before, and arsenic isn’t a new arrival. It’s the same actor that’s always been on stage. The question worth asking is what new substance walked into the room with it.

My own suspicion lands on the chemical load we’ve added to that landscape in the last half century: agricultural pesticides and insecticides, and PFAS, the “forever chemicals” that don’t break down and don’t leave. This isn’t a wild guess. A 2026 USGS model of soils across Maine, Vermont, and New Hampshire found that roughly 73 percent of soil samples exceeded New Hampshire’s remediation threshold for PFOS, and 41 percent exceeded it for PFOA, in areas with no obvious industrial source nearby. Separate USGS groundwater sampling across the eastern U.S. found PFAS in 60 percent of public-supply wells and 20 percent of private domestic wells tested. Nationally, PFAS has now turned up in drinking water serving over 176 million people. None of that proves PFAS causes this specific melanoma. But it establishes that these lakes and the soil around them are carrying a chemical burden that didn’t exist when arsenic was the only story anyone had to tell.

What the dream already knew

A few of the details line up closely enough with the actual research that I want to sit with them instead of moving past them.

The researchers didn’t describe this melanoma as a normal tumor. They described it as a cancer that spreads cell to cell, fish to fish, closer in behavior to a parasite than to conventional cancer. That is close to the exact word my mind reached for on its own, watching worms move through those shells. And the shells themselves weren’t a random detail either. The same paper situates the catfish disease alongside the only three other transmissible cancers ever documented in animals, and one of those three is already a leukemia-like disease known to move through clams, mussels, and other bivalves. My dream put something crawling through shellfish. The actual science had already found a transmissible cancer living in shellfish, years before this catfish study. I didn’t know that fact when I had the dream. I only found it while writing this.

I also don’t think it’s a coincidence that I woke up with the sense that none of it was safe to eat, not the fish and not the shellfish. Whatever that instinct was drawing from, dread, memory, something else, it wasn’t wrong about the water being the thing in question.

The mushrooms are harder to place, and I want to be honest about that rather than force a fit. A transmissible cancer living in lake sediment isn’t a fungal disease, and I’m not going to claim otherwise. But you asked me a fair question separately: could fungal toxins actually reach a lake through rain runoff. The answer is yes, and not as a stretch. Fungicides, the fungal-targeting counterpart to the herbicides and insecticides everyone already worries about, wash off treated fields into nearby waterways every time it rains, the same way the other pesticide classes do. One survey of European surface waters actually found fungicide concentrations running higher on average than either herbicides or insecticides. Separate testing of ponds and lakes has turned up fungicide residues as high as 6 micrograms per liter in the water itself and close to 100 micrograms per kilogram in the sediment, which matters here because sediment is exactly where a bottom-dwelling, scaleless fish spends its entire life. None of that means a fungicide caused this melanoma. But it means the fungal thread in the dream isn’t as far-fetched as it first sounds. It just may be present as a passenger and a stressor rather than as the driver.

The part that worries me for us, not just the fish

Here’s where I want to be careful, because I don’t think this cancer is coming for people the way it moves through catfish. Transmissible cancers are rare precisely because most animals, humans included, have highly diverse immune recognition genes that treat foreign cells, cancerous or not, as something to attack and reject. It’s the same system that makes organ transplants require careful matching. Species like Tasmanian devils that developed this disease had unusually low genetic diversity in exactly those immune genes, which is part of why the tumor could spread unchecked through their population. Humans don’t share that vulnerability. The fish study’s own authors say plainly there’s no known risk to people, and I take that at face value.

What I don’t think we can wave off is the broader pattern the fish are sitting inside of. Early-onset cancers, cancers showing up in adults under 50, have been rising steadily and are now increasing by roughly 3 percent a year in colorectal cancer alone, with close to 1 in 6 new colorectal cancer cases in the U.S. this year expected in someone 49 or younger. Researchers studying this trend keep landing in the same place: genetics move too slowly to explain a shift this fast, so something in the environment shifted instead. Scientists tracking early-onset breast cancer have found that women exposed in the womb or in infancy to the pesticide DDT show a measurably higher risk decades later. Indoor air pollution exposure in early life has been linked to changes in breast tissue density in adolescence. Nearly half the U.S. population lives somewhere with unsafe air pollution levels, and an estimated 200 million Americans are drinking water carrying PFAS.

None of this is a single smoking gun. That’s actually the point. What the bullheads may be showing us, in a body and a timeline small enough to study closely, is what a landscape does to the things living in it once you’ve layered enough new chemistry onto old geology. Arsenic was always there. What wasn’t always there was everything else we added on top of it.

Back to the garden

I don’t know if my father was reaching through a dream to warn me about catfish in Vermont, or mushrooms, or anything at all. Grief works in strange, associative loops, and I don’t fully trust my own explanations for what I see when I’m missing someone this much. But I don’t think a thing has to be fully explained to mean something. Maybe he was pointing at something real, both in that catfish research and in the quieter work I keep circling back to with mushrooms. Or maybe the two threads of my life, the environmental reporting and the private grief, are just weaving themselves together in my sleep, because that is what minds do with the people they’ve lost. Either way, I keep coming back to the image of those shells, clean and abundant on the outside, and what was moving inside them once you looked closely. That feels like an honest description of where we are with a lot of our water right now. Abundant. Familiar. Worth a second look before you decide it’s safe.

Source: https://www.uvm.edu/uvmnews/news/more-parasites-tumors-vermont-scientists-discover-transmissible-cancer-catfish

My grandmother almost never left her village. She went to the city a handful of times in her life, mostly for doctors’ visits. When she came to see us, in our concrete block apartment, she got antsy almost immediately. She loved us, but she could not wait to get back to her house in the mountains, to her garden, to the particular air that was hers. She also had severe motion sickness, bad enough that a car ride could undo her for a day. I have a version of it. So, it seems, does my daughter. Three generations, the same body telling the same story: we were not made to be moved around this much.

I think about her often now, because I have become, in my own more modern and more medicalized way, someone who also cannot simply go anywhere. An illness rewired my tolerance for the built environment, and what used to be background noise, the fragrance aisle, the freshly sealed parking lot, the neighbor’s pesticide truck, now registers as an event my body has to recover from. I call these outings incursions, only half joking. An errand, a hospital visit, an afternoon in a town two exits over, and I come home flattened for a day or two. My husband, who is healthier and restless and reasonable, wants to see places. I understand him. I was, before this, a fairly well traveled person myself, and I am grateful for every mile of it. But something in me has quietly agreed with my grandmother, decades late: if the cluster you already have is good enough, the roots, the family, the garden, the particular slant of light on your own street, maybe that is the whole assignment. Maybe going everywhere was never actually the point.

My own cluster, the town and the string of towns around it, gives me almost everything a person could want. There is real natural beauty here, real gardens, a working art scene, a city forty minutes away with concerts and a genuine food culture. On paper it looks like abundance, but from my perspective, it is hardly the case. And summer changes the math. Heat and humidity together push up airborne mold and bacteria levels indoors, a relationship detailed enough that researchers have started building predictive models for exactly which temperature and humidity combinations tip a building into unsafe bioaerosol territory. At the same time, warm, wet conditions are prime growing season for the fungi that produce mycotoxins outdoors, in soil, mulch, and lawns. And it is, not coincidentally, the season when pesticide use ramps up hardest, on lawns, on golf courses, on town rights of way, on the ornamental gardens that make my area so pretty from the road. So the very months that should be the most rewarding here become, for a nervous system like mine, the most loaded. The beauty and the burden arrive in the same package.

It is tempting to think this is a private, unlucky quirk of my own biology. It is not entirely. There is a whole population of people, mostly invisible to everyone around them, who have been pushed out of ordinary housing and ordinary towns by exactly this kind of exposure, and who have ended up living something closer to a nomadic life as a result. People with multiple chemical sensitivity have described losing careers, homes, and marriages after their bodies stopped tolerating fragrance, laundry exhaust, new carpet, or pesticide drift, the everyday chemistry of modern life that the rest of folks don’t notice. One well known account describes an entire informal community in the American Southwest, people who relocated in search of a place with genuinely clean air, only to become nomadic again when their new town developed allergenic vegetation or nearby construction. A survey of people living with the condition found that nearly all of them had to take special precautions inside their own homes just to make the air livable, and most said they would move again in an instant if safe housing existed. These are not fringe anecdotes so much as an early signal. As the built and chemical environment gets denser, more scented, more sprayed, the number of places that qualify as genuinely tolerable keeps shrinking, and the people most sensitive to that shrinkage are the first to feel it and the first to have to move because of it.

That is the part of this story that I think a wider audience needs to sit with, the part that goes beyond any one person’s illness. We are, collectively, making it harder to find a good place to put down roots. Not through some single dramatic event, but through accumulation: a pesticide season a little longer than last year’s, a new development where a meadow used to buffer the wind, another synthetic fragrance in another laundry product, another building sealed too tightly to breathe. It is quietly displacing a small population of unusually sensitive people right now, and it is a preview, not a separate story, of pressures that will eventually reach less sensitive people too, just on a longer timeline. The nomads of the chemically intolerant world are, in that sense, an early warning system for the rest of us, the canaries who already had to leave the coal mine.

And yet the research on place attachment argues, gently, for the opposite instinct, for staying rather than fleeing wherever possible. People who remain rooted in one place long enough tend to develop real emotional and psychological benefits from it, a sense of belonging and identity that researchers call rootedness, and that rootedness appears to buffer stress and support well being, particularly later in life. Studies on residential mobility have found that disruption from moving is not just a short, sharp shock that fades; the health consequences can unfold slowly, over years, as a person’s whole social and practical infrastructure has to be rebuilt from scratch. In other words, the constant motion our culture treats as freedom, and even as a kind of achievement, may carry a cost we rarely account for. We have built an entire identity around the idea that we are entitled to experience everywhere, that a good life requires seeing as much of the world as possible. That idea is barely a century old, made possible only by cheap flight and cheap fuel, and I am no longer sure it is either good for us or actually necessary.

I do not say this from a place of resentment toward my husband, who deserves to see the world, or toward the version of me that once did too. I say it because I have quietly run the experiment on my own body and gotten a clear result. I have traveled. I have also come home from a two hour errand feeling like I ran a race I did not train for. Somewhere in between those two facts is a truth my grandmother lived without ever having to argue for it: a good cluster, tended and known and returned to, might be worth more than a hundred good clusters glimpsed once and left behind. She had her village, her garden, her family coming to her instead of the other way around. She got carsick if you took her too far from it, and she never seemed to think that was a defect. It was, maybe, just her body agreeing with her mind about where she was supposed to be.

I have seen enough. I have done enough. What I am looking for now is not another place to visit. It is a town with genuinely good air, the kind my body does not have to recover from, the kind I could simply live inside of and never have to leave. My grandmother found hers in the mountains, without ever calling it a philosophy. I am still looking for mine. But I suspect that when I find it, I will understand, finally, exactly what she knew.

Sources referenced

• Zhang et al., “Emotionally Healthy Ageing-in-Place: Residential Normalcy, Place Attachment and Mental Well-Being of Elderly Migrants,” Population, Space and Place, 2025

• “Residential Place Attachment as an Adaptive Strategy for Coping With the Reduction of Spatial Abilities in Old Age,” National Institutes of Health / PMC

• Research summary, “Does Place Attachment Affect Social Well-Being?” (residential mobility and long-term health effects)

• “The Effect of Housing on Individuals with Multiple Chemical Sensitivities,” compiled survey data (Gibson et al., Davis et al., Caress and Steinemann, among others)

• “No Safe Haven: People With Multiple Chemical Sensitivity Are Becoming the New Homeless,” reporting on MCS communities in the American Southwest

• ScienceDirect, “Revisiting the Joint Effect of Temperature and Relative Humidity on Airborne Mold and Bacteria Concentration in Indoor Environments,” 2025

• “Climate Change and Effects on Molds and Mycotoxins,” PMC

• 23andMe genome-wide association study on motion sickness, published in Human Molecular Genetics, 2015

• MedlinePlus Genetics, “Motion Sickness”

On June 25, President Trump stood in the Oval Office with Health and Human Services Secretary Robert F. Kennedy Jr. and Agriculture Secretary Brooke Rollins to sign an executive order promoting regenerative agriculture. The administration framed it as a turning point: soil health, farm resilience, and a food system built around fewer chemical inputs. Five days later, on June 30, the Environmental Protection Agency approved two new pesticides built from fluorinated chemicals for use on the country’s two most widely planted crops, corn and soybeans, with one also cleared for wheat.

To an outside observer, the two announcements might look contradictory. They came from the same administration within the same week. But they did not come from the same people, the same meetings, or, in any meaningful sense, the same decision-making process. That gap helps explain something larger about how federal policy is actually produced, and why the same government can appear to move in opposite directions at once.

## The week in question

The regenerative agriculture order directed HHS, USDA, and the EPA to build a joint research framework on cumulative chemical exposure in the food supply and launched a National Institutes of Health prize challenge aimed at reducing reliance on chemical crop protection. Rollins paired it with a finalized Regenerative Feedstock Rule connecting soil-health practices to premium biofuel markets for corn, soybeans, sorghum, and canola, building on a $700 million pilot program the department had rolled out the previous December. USDA noted that a majority of corn and soybean farmers already use at least one regenerative practice, and framed the rule as a market-based incentive rather than a mandate.

Then came the pesticide approvals. According to the Center for Biological Diversity, the EPA’s June 30 registrations covered diflufenican and epyrifenacil, two fluorinated compounds never before used in the United States, for corn and soybeans, with epyrifenacil also approved on wheat. The agency additionally expanded approved uses of a previously registered fluorinated pesticide, bifenthrin, to include coffee, kiwifruit, peas, kale, and broccoli. The timing drew particular scrutiny because the approvals landed just days after the Supreme Court sided with Bayer and the administration in a ruling that narrows Americans’ ability to sue pesticide manufacturers over alleged harms.

The EPA disputes the “forever chemical” label for these newer compounds. In a statement responding to what it called misinformation, the agency’s Office of Chemical Safety and Pollution Prevention said its 2023 regulatory definition of PFAS, which requires two or more fully fluorinated carbons, was developed through a public rulemaking process and that single-fluorinated-carbon compounds do not display the persistence associated with forever chemicals. The agency said its approved pesticides underwent the toxicity testing required under federal law and found no risks of concern when used as labeled.

That distinction matters, and it is genuinely contested. Advocacy groups counter that the EPA’s narrower definition departs from the one used by most states, written into past defense authorization law, and endorsed by more than 150 PFAS researchers internationally. Under that broader and more widely used definition, they argue, the newly approved compounds qualify as PFAS. Freedom of Information Act records cited by the Center for Biological Diversity show that a webpage initially acknowledging this conflict was revised weeks later to remove the caveat, with the changes reviewed by EPA Administrator Lee Zeldin.

## Who was actually in the room

Neither of these actions was made by “the EPA” or “the USDA” as monolithic entities. They were made by specific offices staffed by specific people, operating under different statutory mandates, different political sponsors, and different outside constituencies.

The regenerative agriculture push traces to HHS and USDA leadership aligned with the Make America Healthy Again coalition, a loose alliance that includes wellness advocates, some organic and regenerative farming interests, and food-system reformers skeptical of chemical-intensive agriculture. The pesticide registrations trace to the EPA’s pesticide program, where, according to reporting cited by public radio outlet KALW and confirmed across multiple advocacy filings, several senior political appointees came directly from the industries they now regulate: Kyle Kunkler previously lobbied for the American Soybean Association before becoming deputy assistant administrator for pesticides, working under Nancy Beck and Lynn Dekleva, both former American Chemistry Council lobbyists, under an office head who was confirmed with the chemistry council’s public endorsement.

This is not a story about one rogue office defying an otherwise unified administration. It is closer to the ordinary condition of the modern executive branch. Agencies are staffed through different appointment processes, subject to different congressional committees, and embedded in different professional and lobbying ecosystems. The people who negotiate soil-health incentives with farm groups are, in practice, rarely the same people who evaluate a pesticide’s toxicology data under the Federal Insecticide, Fungicide, and Rodenticide Act. A president’s executive order can set a broad direction, but the specific, technical determinations, like whether a compound clears a safety threshold, are made deeper in the bureaucracy, often years into a review process that predates the current political leadership.

## The pattern is not new, or one-sided

This isn’t the first time the same administration’s agencies have pulled in different directions on pesticide policy. In January, the EPA approved isocycloseram, another fluorinated insecticide, for use on a wide range of food crops including apples, tomatoes, and almonds, along with lawns and golf courses. The agency’s own data showed the compound reduced testicle size and sperm counts and caused liver damage in manufacturer-sponsored animal studies; Australian regulators separately found evidence of fetal skeletal malformations that the EPA disputed. Conservation groups sued in the Ninth Circuit, and the EPA’s own research indicated bees foraging near treated orchards could be exposed to roughly 1,500 times a lethal dose.

It is worth noting that criticism of the administration’s food and farm record has not come only from its usual opponents. David Murphy, a former top fundraiser for Kennedy’s own presidential campaign, praised the regenerative agriculture pilot program as a step forward but pointed out that USDA cut more than a billion dollars from farm-to-school and farm-to-food-bank programs the same year, calling it evidence there is still a long way to go. Robby Sansom, chief executive of the sustainable-agriculture group Force of Nature, made a related point: the federal Farm Bill, a program worth tens of billions of dollars, still effectively requires heavy chemical use for crop insurance eligibility, working against the very outcomes the new pilot is meant to encourage. In other words, even allies inside the MAHA-aligned coalition describe the government as internally inconsistent, not because any single official is acting in bad faith, but because different programs, written into law at different times under different pressures, are still running simultaneously.

## What the underlying science says

The stakes of the PFAS pesticide debate are not abstract. PFAS compounds are called forever chemicals because their carbon-fluorine bonds resist environmental and biological breakdown, allowing them to accumulate in soil, water, and human tissue over years of low-level exposure. A Harvard-led study of roughly 69,000 people exposed through contaminated drinking water found higher rates of certain cancers and metabolic disorders compared with unexposed populations, and controlled research has found measurable immune changes at relatively low serum PFAS levels. The Centers for Disease Control and Prevention and the National Academies of Sciences both maintain ongoing guidance on PFAS exposure risk, reflecting a scientific consensus that cumulative, long-term exposure, rather than any single dose, is the primary concern. Current pesticide approval frameworks are built around shorter-term toxicity testing, which is part of why the “no risks of concern” finding for a newly registered pesticide and the “This is a public health problem” framing from environmental groups can both be technically defensible descriptions of the same approval, depending on which time horizon and which regulatory definition is applied.

## The deeper question

There is a natural conclusion to draw from all of this: that better outcomes depend on installing people with genuine principle into positions of power, and that a sufficiently independent-minded leader might simply be less movable by industry pressure than the system around them. There is something to that. Individual character matters, and agencies are run by individuals. But the pattern described above suggests something more structural is also at work. Even a cabinet secretary who is personally resistant to industry influence does not personally review pesticide toxicology files or approve individual chemical registrations. Those determinations sit several layers down, inside offices where, on the pesticide side of this story, several of the most senior technical positions have been filled by people who came directly from the industries under review. A leader’s convictions can set the tone at the top of an agency without necessarily reaching the office two floors down that signs off on a chemical registration.

This is the argument political scientists and legal scholars have made for decades under the banner of regulatory capture: that agencies tasked with overseeing an industry can gradually come to reflect that industry’s interests, not through corruption in the criminal sense, but through the ordinary mechanics of expertise, staffing, and access. The people with the deepest technical knowledge of a chemical’s registration pathway are often the people who spent their careers inside the companies seeking that registration. That is a structural feature of how technical regulation works, not a claim about any individual’s honesty.

None of this means the regenerative agriculture push is hollow, or that the pesticide approvals are indefensible on their own terms. It means the federal government is not one actor with one intention. It is a federation of offices, each with its own leadership, statutory obligations, professional culture, and outside relationships, occasionally pointed in the same direction by a president’s signature, but just as often left to pursue their separate mandates on separate timelines. Understanding policy as the product of that fragmented system, rather than as a single coherent strategy, is a more accurate way to read weeks like this one, and a better starting point for anyone trying to change the outcome.

---

**Sources**

- Center for Biological Diversity, “Trump EPA Approves Two More ‘Forever Chemical’ Pesticides for Use on Most Widely Grown U.S. Crops,” June 30, 2026
- Common Dreams, “’A National Outrage’: Days After Monsanto Ruling, Trump EPA Approves More Forever Chemical Pesticides,” June 30, 2026
- Earthjustice / Center for Biological Diversity, “Lawsuit Challenges Trump EPA’s Latest Approval of ‘Forever Chemical’ Pesticide,” January 15, 2026
- Public News Service, “Suit challenges EPA approval of new ‘forever chemical’ insecticide,” January 26, 2026
- U.S. EPA, “FACT CHECK: EPA Debunks False Claims that Agency Recently Approved ‘Forever Chemical’ Pesticides”
- KALW, “EPA approves pesticides containing forever chemicals for use on food,” January 5, 2026
- The Washington Post, “EPA moves to approve new ‘forever chemical’ pesticides,” November 22, 2025
- USDA, “President Trump Signs Executive Order Advancing Regenerative Agriculture; Secretary Rollins Announces USDA Rule to Unlock Billions for American Farmers,” June 25, 2026
- HHS.gov, “President Trump Signs Executive Order Advancing Regenerative Agriculture as Part of Make America Healthy Again Agenda,” June 25, 2026
- AgWeb, “USDA Launches New $700 Million Regenerative Ag Pilot Program,” December 2025
- AgFunderNews, “’Investing in regenerative and organic is not a political stance’: agrifood reacts to USDA’s regen ag pilot,” December 12, 2025
- MEAT+POULTRY, “USDA, HHS promote regenerative agriculture under new rule,” June 26, 2026

*Note on sourcing: Several claims above rely on findings and framing from advocacy organizations (the Center for Biological Diversity, Earthjustice, Center for Food Safety) whose stated mission is to challenge these approvals, alongside the EPA’s own public rebuttal. Readers should weigh both sides; a link to primary source documents (EPA registration decisions, the executive order text, and the underlying FOIA records) is recommended before publication.*

Every day, somewhere in America, a mountain of garbage disappears into fire. The stack above the plant releases a plume into the sky, and the plume drifts. It drifts over the elementary school on the corner. It settles into the soil of the community garden two blocks away. It enters the lungs of the child waiting at the school bus stop. This is not a hypothetical. This is Tuesday.

There are roughly 60 to 72 municipal solid waste incinerators still operating in the United States, depending on the year and the counting method. They are concentrated in the Northeast, Florida, and the upper Midwest. They burn somewhere between a quarter and a third of a million tons of garbage every year. And according to research from the Tishman Environment and Design Center at The New School, approximately 4.5 million Americans are exposed to their pollution, with 80 to 85 percent of those facilities located in environmental justice communities, meaning low-income neighborhoods, communities of color, or both.

The industry prefers to call these plants “waste-to-energy” facilities, a term that describes the electricity some of them generate as a byproduct of combustion. The framing is deliberate, and it works: it conjures images of clean modern technology transforming society’s discards into something useful. The reality, as decades of epidemiological research suggest, is considerably darker. What goes up these stacks comes back down. The question that too few people ever get to ask before moving near one is: what exactly is coming down, and what does it do to a human body over years of exposure?

4.5 million Americans exposed to incinerator pollution

80% of US incinerators sited in environmental justice communities

9 air pollutants the EPA regulates, out of 13,000+ chemicals used in plastics production

What burns, and what escapes

Modern waste incinerators are not simply bonfires with better PR. They burn at extremely high temperatures, and they are equipped with a layered suite of pollution control technology: electrostatic precipitators, fabric filter baghouses, acid gas scrubbers, selective catalytic reduction systems for nitrogen oxides, and activated carbon injection to capture mercury and dioxins. When operating correctly, these systems remove impressive percentages of certain pollutants before the gas reaches the smokestack.

The problem lies in the gaps. Equipment requires continuous maintenance, and performance degrades over time. During startup, shutdown, or mechanical malfunction, emissions can spike dramatically above permitted levels. Older facilities, many of which are approaching or exceeding their designed lifespan, may lack modern control technology entirely and continue operating under legacy permits. And critically, even a well-maintained system with state-of-the-art controls is only regulated for a small fraction of what it actually produces.

Plastic is the invisible accelerant in this equation. As plastic has come to constitute a growing share of the American waste stream, incinerators are burning more of it. More than 13,000 chemicals are used in plastics production, and when plastic burns it releases a complex chemistry of harmful compounds. The EPA currently regulates waste incinerators for only nine air pollutants. Everything else goes up the stack, unmonitored and unreported.

Here is what we know is coming out:

Dioxins and furans (PCDD/F). Formed during combustion of chlorinated materials. Persistent, bioaccumulative, and carcinogenic. There is no known safe level of exposure. They concentrate in fatty tissue and breast milk, meaning the most vulnerable transmission pathway may be from mother to nursing infant.

PFAS (”forever chemicals”). Released when plastics, textiles, food packaging, and firefighting foam are incinerated. Linked to cancer, thyroid disruption, and reproductive harm. Not currently tracked by the EPA at incinerator sites.

Heavy metals. Lead, mercury, cadmium, arsenic, and chromium concentrate in fly ash and stack emissions. Mercury persists in vapor form even after passing through control systems, settling into waterways and accumulating in fish.

Fine particulate matter (PM2.5). Particles small enough to penetrate deep lung tissue and enter the bloodstream. Associated with cardiovascular disease, respiratory illness, and premature death even at low concentrations.

Nitrogen oxides. A precursor to ground-level ozone and smog. Contributes to asthma exacerbation, lung inflammation, and reduced respiratory function, particularly in children and the elderly.

Hydrogen chloride and acid gases. Produced when chlorine-containing materials combust. They irritate and damage airways, and react in the atmosphere to produce secondary pollutants including fine particulate matter.

There is also the matter of ash. Incineration does not make garbage vanish; it transforms it. The residue left behind, divided into bottom ash from the combustion chamber and fly ash captured by pollution controls, typically amounts to 25 to 30 percent of the original waste volume. This ash is highly concentrated with heavy metals and persistent organic pollutants. When it is disposed of in landfills or ash lagoons, rain percolating through it can leach toxic metals into groundwater. Studies have found contaminated soils within a 60-meter radius of ash dump sites, but the contamination pathway through groundwater extends the effective footprint far further.

One particularly disturbing finding from laboratory research is that incinerators can actually synthesize new dioxins during combustion, through a process called de novo synthesis, in which dioxins form on carbonaceous surfaces at moderate temperatures. Some research has found that the amount of dioxin leaving an incinerator can exceed the amount entering it as raw waste. The process of burning garbage, in other words, may make certain toxins more abundant, not less.

How far the plume travels

A common assumption is that proximity to an incinerator is what primarily determines risk. Move a mile away, the thinking goes, and the danger recedes to background noise. This is not quite how the physics works.

PFAS compounds are particularly stubborn travelers. These synthetic chemicals, used in everything from nonstick cookware to waterproof clothing to food packaging, do not break down under ordinary conditions. It was widely assumed that high-temperature incineration would destroy them. It does not, at least not reliably. Research published in 2020 from Bennington College found PFAS contamination in soil and surface water samples collected 31 miles from a commercial incineration facility in Cohoes, New York, that had burned firefighting foam. A separate EPA modeling exercise found that 97.4 percent of a PFAS compound called GenX emitted from one facility traveled more than 93 miles before depositing.

Dioxins behave differently but no less persistently. Being lipophilic, they attach to fat molecules and accumulate in animal tissue, including human tissue. European biomonitoring research conducted near incinerators in France, Spain, and the Netherlands found dioxin concentrations in backyard chicken eggs exceeding EU safety limits at all three sites. At a schoolyard playground in Paris’s Ivry-sur-Seine district, researchers flagged contamination at serious levels of concern. In Harlingen, Netherlands, PFAS concentrations in water near an incinerator were measured at 138 times the Dutch legal drinking water threshold.

The food chain implication of this is important and under-discussed. Dioxins that settle on pasture land are consumed by cattle and concentrate in beef and dairy. Dioxins that settle on the surface of ponds and rivers are absorbed by algae, consumed by small fish, consumed by larger fish, consumed by humans. Mercury released from incinerators remains in vapor form even after passing through pollution control systems and eventually deposits into waterways, where it bioaccumulates in fish. A family eating fish caught from a local lake five miles from an incinerator may have no idea they are being chronically exposed to a substance their bodies cannot clear.

Documented contamination reach:

• Under 2 km: Highest dioxin concentrations in soil, vegetation, and eggs. Immediate neighborhood risk is clearest.

• 2 to 10 km: Japanese research linked elevated infant death rates across this entire radius near high-dioxin facilities.

• Several miles: Airborne PFAS deposited in soil and water; contaminated surface water sampled 31 miles from a PFAS incinerator in New York.

• 93+ miles: EPA modeling found 97.4% of GenX PFAS emitted from one facility traveled more than 93 miles before deposition.

What the science says about health

The epidemiological literature on incinerators and health is large enough to be taken seriously and contested enough to generate genuine scientific debate. Industry representatives point to modern European facilities and note that some peer-reviewed meta-analyses have not found increased cancer risk in surrounding populations, with one notable exception: laryngeal cancer in women, which showed a statistically elevated risk. Operators of newer plants in Europe and some in the United States argue that their facilities, when properly maintained and monitored, produce negligible emissions.

The more honest reading of the evidence is that the picture is complicated by the enormous variation in facility age, technology, regulation, and enforcement across different sites. American incinerators, many of which are operating with outdated equipment under regulations last updated nearly two decades ago, are a different beast from a modern Scandinavian waste-to-energy plant with continuous real-time monitoring and strict EU emission limits.

A 2025 systematic review and meta-analysis published in BMC Public Health synthesized the available evidence on residential exposure to municipal solid waste incinerators and found evidence sufficient to raise ongoing concern, while acknowledging that many studies were conducted on older facilities that may not reflect newer technology. A separate systematic review in the NIH literature found evidence of increased risk of adverse birth and neonatal outcomes for residents near incinerator sites, as well as some evidence of increased mortality risk.

Japanese research, widely cited in this field, examined reproductive outcomes near 63 municipal solid waste incinerators with high dioxin emissions and found a statistically significant peak-decline pattern for infant deaths and infant deaths with congenital malformations, with risk elevated across the full 10-kilometer study zone. Researchers in Hartford, Connecticut, observed increasing rates of cancer and respiratory conditions among Black and Hispanic populations near that city’s MIRA incinerator, which burned 600,000 tons of waste per year from over 70 towns across its 30-year operating life.

The documented and plausible health effects for long-term residents near these facilities include:

• Respiratory disease including asthma and chronic obstructive pulmonary disease

• Elevated cardiovascular risk from fine particulate matter exposure

• Neurological effects from lead and mercury, particularly in children whose developing brains are acutely vulnerable

• Potential endocrine disruption from dioxins and PFAS affecting thyroid function, reproductive hormones, and metabolic regulation

• Increased risk of certain cancers, with liver, kidney, and blood cancers appearing in some study findings

• Adverse birth outcomes including low birth weight and congenital malformations

The geography of exposure

Where these facilities are sited is not random. The Energy Justice Network has documented that while roughly 67 percent of American trash incinerators are technically located in majority-white communities, the largest and most polluting ones cluster in communities of color. Fifteen of the 20 largest incinerators in the country, representing disproportionate shares of total national emissions, are in majority Black, Indigenous, or other people of color communities. On average, incinerators in majority BIPOC communities are surrounded by 2.5 times as many people and are twice as large as those in majority-white communities.

Massachusetts burns more trash per capita than any other state except Connecticut, and six of the state’s seven incinerators are located in environmental justice communities. Florida operates nine, six of which are in areas where the percentage of residents of color exceeds the state average. Minnesota ranks third nationally in incinerator count, with seven facilities, and is actively debating whether to close or expand them.

In Miami-Dade County, the collapse of the county’s old trash incinerator in a 2023 fire has forced officials to make a politically charged decision about where to build a planned new facility capable of burning 4,000 tons of garbage per day. The deliberations have become a case study in the dynamics of environmental siting: no community wants the plant, and the communities with the least political power to refuse it remain the most likely recipients.

The pattern persists because of what sociologists call expulsive zoning, the historical practice by which whiter and wealthier communities used legal and political mechanisms to exclude industrial land uses from their borders. The long-term consequence is a geography of pollution in which the people bearing the health burden of waste disposal are rarely the same people generating the most waste.

Europe as a complicated mirror

American observers sometimes point to Europe, where waste-to-energy incineration is widespread, as evidence that the technology can be made safe. Nearly a quarter of all municipal solid waste in the European Union is burned in approximately 450 incinerators, and European facilities generally operate under stricter emission standards than their American counterparts, with continuous monitoring requirements and regular public reporting mandated by EU directives.

Industry groups cite World Health Organization assessments and European academic studies finding no evidence of increased cancer or respiratory disease near modern, compliant waste-to-energy facilities. A UK Health Security Agency review updated in 2025 concluded that modern, well-run municipal waste incinerators are not a significant risk to public health.

But European environmental advocates push back hard on this framing. Independent biomonitoring research conducted near facilities in Spain, France, and the Netherlands in 2025 found dioxin levels in eggs, soil, and water exceeding EU legal limits at every site studied. More than 150 organizations have urged EU leaders to ban the construction of new incinerators, citing health and climate concerns. Zero Waste Europe argues that even compliant modern facilities produce toxic residues under normal operating conditions, and that real-time monitoring of persistent organic pollutants is inadequate in almost all jurisdictions. The regulatory and scientific debate in Europe is not settled; it is active and contested.

The comparison also obscures a structural difference in waste culture. European countries with high incineration rates, such as Germany, the Netherlands, and the Scandinavian nations, also have among the highest recycling rates in the world. Incineration there functions as a downstream residual treatment for material that genuinely cannot be recycled. In the United States, where recycling infrastructure is weaker and less uniform, incinerators compete with and arguably undermine recycling by creating a financial incentive for facilities to receive high volumes of waste, regardless of whether that waste could be better handled another way.

The unknowns may be the most important part

Every conversation about incinerator health effects eventually bumps into the limits of what science has been able to measure. Risk assessments for these facilities have historically focused on a narrow set of well-characterized compounds: dioxins, furans, a small suite of heavy metals, particulate matter. The assumption embedded in this approach is that what is not measured does not matter, or at least cannot be regulated.

This assumption deserves skepticism. The 13,000-plus chemicals used in plastics production represent a largely unmapped frontier. When those chemicals combust at high temperatures in the presence of other materials, the reactions produce compounds that have never been characterized, let alone tested for toxicity. Some of those compounds will land in the soil and water of surrounding communities. Some will enter the bodies of people who live there. Their effects may not be measurable for years or decades, and they may never be conclusively linked to the incinerator at all.

Consider what we know about PFAS: these compounds were manufactured and used for decades before anyone understood that they were bioaccumulating in nearly every human body on earth and were linked to cancer, hormonal disruption, and immune suppression. The incinerator down the road may be releasing compounds with similar profiles that have not yet been identified, let alone regulated. The absence of evidence is not the same as evidence of absence, especially when the regulatory framework is not designed to look.

There is also the cumulative exposure problem. A person living near an incinerator in an industrial corridor may also live near a highway, a chemical plant, or a power station. Each source of pollution has been studied in relative isolation. The interactive effects of chronic simultaneous exposure to dioxins, fine particulate matter, nitrogen oxides, PFAS, and heavy metals over twenty or thirty years are not well understood because no regulatory framework has been designed to capture them, and no study has adequately modeled them. The body is not exposed to one chemical at a time. The cumulative burden on communities living at the intersection of multiple pollution sources is likely to be considerably worse than any single-source study would suggest.

What to consider before settling near an incinerator

Search EPA’s EJScreen tool and the Energy Justice Network’s interactive incinerator map before purchasing or renting a home. Locate all major industrial sites within five miles, not just the nearest one.

Prevailing wind direction matters as much as distance. A facility two miles upwind poses a different risk than one two miles downwind of your home.

Avoid purchasing or growing produce from backyard gardens within three kilometers of an active facility without first testing the soil for heavy metals and persistent organic pollutants.

Be skeptical of “waste-to-energy” framing. The energy output does not neutralize the emissions. Ask what the facility burns, how old its equipment is, and when its permits were last updated.

Children, pregnant women, people with existing respiratory conditions, and the elderly face elevated risk from the same exposure levels that may not be acutely noticeable in healthy adults.

Regulators do not monitor for PFAS emissions from incinerators. If you live downwind and use a private well, consider independent water and soil testing regardless of what your municipality tells you about water quality.

The ash produced by incineration is as significant a contamination pathway as the stack emissions. Ask whether any nearby ash disposal sites exist in addition to the facility itself.

The question of where to live

The Location Effect begins with a simple premise: where you live shapes your health, often in ways that are invisible until you start looking. Incinerators are one of the clearest examples of this principle. They are large, permanent, and their emissions are not contained by property lines. The chemistry they release into the air, soil, and water of surrounding communities is real, documented, and in many cases irreversible over any meaningful human timescale.

None of this means that everyone living near an incinerator will become sick. Human health is a product of genetics, behavior, cumulative environment, and chance. But it does mean that the environmental baseline for people in these communities is worse than it should be, that the additional biological burden they carry is real, and that in most cases they were never asked whether they consented to carry it. Many of them do not know the facility is there, do not know what it emits, and have no practical access to the data that would allow them to make an informed choice.

Choosing where to live is, for most people, one of the most consequential health decisions they will ever make, and they make it without a fraction of the information they would need to make it well. This newsletter exists to provide some of that information. When it comes to waste incinerators, the information is this: the science is imperfect, the unknowns are real, and the precautionary instinct, to put distance between yourself and these facilities when you have the option to do so, is grounded in evidence, not paranoia.

The plume drifts. It does not ask permission.

Sources: Tishman Environment and Design Center, The New School (2019); Moms Clean Air Force / EPA rulemaking record (2024); BMC Public Health systematic review (2025); NIH/PMC municipal solid waste health review; Energy Justice Network incinerator database; Zero Waste Europe / ToxicoWatch Foundation biomonitoring research (2025); Bennington College PFAS field study (2020); Environmental Working Group PFAS cycling report; Japanese MSOWI reproductive outcomes study (Environmental Health Perspectives); Conservation Law Foundation; KFF Health News / WUSF investigative reporting (2024); EPA EJScreen; Center for New York City Affairs / GAIA interactive incinerator map.

Something strange keeps happening on social media.

Celebrities, influencers, and ordinary travelers return from weeks in France, Italy, or Spain and report the same astonishing thing: they ate gluten. They drank wine at noon. They had croissants for breakfast and pizza for dinner, and they felt (inexplicably, wonderfully) fine. Americans who cannot touch a slice of white bread at home without hours of regret describe wandering through Roman markets eating fistfuls of pasta with zero consequence.

The reflexive explanation has always been stress, portion size, mindfulness, or the romantic power of vacation. But a quieter, more uncomfortable theory has begun to circulate among scientists, epidemiologists, and food safety researchers, and it deserves to be taken seriously, not as settled fact, but as a hypothesis the evidence is beginning to support.

What if American food (not just its additives and its dyes and its high-fructose corn syrup) but the very soil it grows in, is harboring microbial threats that European soil is not?

I. The Sludge Beneath Our Feet

Begin with a fact so mundane it borders on invisible: the United States spreads human sewage on its farmland.

The EPA estimates that approximately 2.39 million dry metric tons of treated sewage sludge (renamed “biosolids” by an industry that understood the marketing problem) were applied to American crop fields in 2024 alone. Roughly 60 percent of the nation’s sludge ends up on agricultural land each year.

The nutrients in sludge are genuine. Nitrogen, phosphorus, and potassium make crops grow, and farmers in an era of expensive synthetic fertilizer welcomed a free or cheap alternative. What arrived with it, science is now documenting in disturbing detail, is something else entirely.

“The pathogen risks from land application of sewage sludge have never been adequately evaluated. We are, in the most literal sense, eating in the dark.”

Sewage sludge is not simply fertilizer. It is a mixture of human waste, industrial discharge, hospital effluent, pharmaceutical residue, road runoff, personal care products, and heavy metals. Processing (heat drying, composting, anaerobic digestion) can reduce some pathogens. It does not eliminate them, and it does not touch PFAS “forever chemicals,” antibiotic resistance genes, endocrine disruptors, or hundreds of industrial compounds the EPA has documented but does not regulate in sludge.

The EPA has catalogued 726 chemicals in biosolids since testing began in 1993. The more than 9,000 PFAS compounds are not among the substances required to be tested.

Peer-reviewed research published in Environmental Health Perspectives found that residents living near biosolid application sites reported “a prevalence of Staphylococcus aureus infections of the skin and respiratory tract” following exposure to winds blowing from treated fields. A documented outbreak of staph infections traced to a single land-application site in Robesonia, Pennsylvania saw eight of nine residents in one household contract infections over a five-year period.

A model published in Environmental Health Perspectives in 2008 found that the public health risk from exposure to pathogens in biosolids had, at that point, never been quantitatively assessed, because no appropriate model and no systematic exposure data existed. A 2002 National Research Council committee reached an almost identical conclusion. That finding has not materially changed in the two decades since.

By the numbers:

• 4 million dry metric tons of sewage sludge generated annually by U.S. wastewater plants (EPA, 2024)

• ~70 million acres of U.S. farmland potentially tainted by biosolid-derived chemicals, per Environmental Working Group estimates

• 4.5 billion pounds of sludge spread on farm fields or used in compost in 2023 alone

• 27 states had no existing or proposed legislation on PFAS in biosolids, per a 2023 survey of states

II. Antibiotic Resistance Growing in the Crop Field

The biosolids problem intersects with a second and perhaps more alarming development: the emergence of antibiotic-resistant pathogens not in hospitals, but in agricultural soil itself, bred in part by the routine application of antibiotics directly to crops.

The U.S. EPA has approved antibiotics for direct application as pesticides on American crops. Streptomycin and oxytetracycline, both medically critical antibiotics in humans, have been sprayed on hundreds of thousands of acres of citrus in Florida and California and on fruit trees across much of the country. The U.S. Geological Survey estimated more than 125,000 pounds of these antibiotics were applied to crops in 2018 alone.

In 2025, a coalition of public health and farmworker organizations filed an emergency petition asking the EPA to cancel all such registrations, citing CDC data submitted to the agency in 2017 showing that agricultural spraying of these antibiotics could select for resistant bacteria in environmental settings.

The mechanism is not subtle. As a 2024 review summarized:

“In almost every region where streptomycin has been used to control bacterial diseases in the United States, bacterial populations resistant to this antibiotic have been detected.”

Pesticide stress, separate research found, enhances the acquisition of antibiotic resistance through several routes: activating efflux pumps that flush antibiotics out of bacterial cells, inhibiting outer membrane pores through which antibiotics enter, and inducing gene mutations. Crucially, pesticides also appear to promote the transfer of antibiotic resistance genes between bacteria by increasing cell membrane permeability.

The World Health Organization now reports that one in six confirmed bacterial infections worldwide in 2023 was resistant to antibiotic treatment, and that resistance rose in more than 40 percent of monitored pathogen-antibiotic combinations between 2018 and 2023, at an annual rate of 5–15 percent.

The question is not whether antibiotic-resistant organisms are present in American agricultural soil. The question is how much of what we eat carries them, and whether our guts are simply failing to tell us in a language we recognize as illness.

III. A Regulatory Divide That May Explain a Lot

The contrast with Europe is not incidental. It is structural.

The European Union operates under the precautionary principle: substances that show evidence of potential harm are restricted until proven safe. The United States inverts this logic: additives and agricultural chemicals are generally permitted unless harm is conclusively demonstrated.

The result is a specific and enumerable list of substances Americans eat that Europeans do not:

SubstanceUnited StatesEuropean UnionGlyphosate (pre-harvest)Permitted on 70+ crops, days before harvestPre-harvest use prohibited EU-wide since 2023Streptomycin (antibiotic pesticide)Approved for citrus, apples, pearsBanned or heavily restrictedBiosolids on cropland~60% of sludge land-applied; minimal testingStricter standards; nations moving toward prohibitionPotassium bromate (bread)PermittedBannedAzodicarbonamide (dough conditioner)PermittedBannedrBGH / rBST (dairy growth hormone)PermittedBannedChlorpyrifos (insecticide)Use continuesBanned

Glyphosate deserves particular attention in the context of gut health. The herbicide works by blocking the shikimate pathway, an enzyme system present in plants and bacteria but not in human cells. Regulators long cited that absence as evidence of safety.

But the bacteria in the human gut do use the shikimate pathway.

Animal and cell studies suggest glyphosate exposure alters gut flora balance and intestinal integrity, which may amplify the symptoms many Americans attribute vaguely to “food sensitivities.” In the U.S., allowable glyphosate residue limits in food have actually been raised in recent years to accommodate pre-harvest desiccation practices. In Europe, pre-harvest spraying onto food crops is not permitted.

IV. What This Might Mean, and What It Doesn’t

To be rigorous: the celebrities eating baguettes without incident in Paris are not evidence. Anecdote is not data. Vacation eliminates stress, changes eating patterns, shifts sleep, and alters mood, all of which affect digestion independently of anything in the food itself. The “I can eat gluten in Europe” phenomenon could have a dozen explanations, most of them banal. There is also something related to changing environments and a shift in immune reactivity.

But the underlying scientific question, whether the microbial environment of American agricultural soil has been meaningfully altered by decades of biosolid application, antibiotic pesticide use, and comparatively permissive chemical regulation, is not banal. It is a legitimate and largely uninvestigated hypothesis.

The regulatory frameworks that would generate systematic answers do not yet exist. Most states have no testing requirements for PFAS or antibiotic resistance genes in biosolids. The EPA has catalogued 726 chemicals in sludge and does not require monitoring for most of them. The CDC submitted data to the EPA in 2017 documenting resistance risks from agricultural antibiotic spraying, and the EPA approved expanded use anyway.

The biosolids contamination of American farmland could be one mechanism. The proliferation of antibiotic-resistant organisms in pesticide-treated soil could be another. The additive burden (the cumulative effect of compounds banned elsewhere but routinely consumed here) is a third. None of these explanations is complete on its own. And the honest answer, the one that should unsettle everyone who has eaten a meal in this country today, is that we do not actually know which of them, or which combination, is bearing weight.

Science does not yet have the full picture. But the shape of what is emerging (the scale of biosolid application, the documented presence of antibiotic-resistant pathogens in agricultural environments, the widening regulatory gap between the U.S. and Europe) suggests that the social media travelers posting disbelievingly from Italian tables may be pointing, inadvertently, at something real.

Their bodies, apparently, noticed a difference.

Perhaps it is time for our regulatory agencies to start looking for one too.

Sources: U.S. EPA Biosolids Annual Reports (2024); Environmental Working Group; Lewis et al., Environmental Health Perspectives (2002); Eisenberg et al., Environmental Health Perspectives (2008); Beyond Pesticides (2024, 2025); WHO Global Antimicrobial Resistance Surveillance (2024); Environmental Council of the States (2023); ANSI Blog on EU/US food standards; Science Insights.

This piece presents one scientific hypothesis among several possible explanations for reported cross-Atlantic differences in food tolerance. It does not constitute medical advice.

Picture the homes these men came from.

It is 1979. They are in their late seventies and early eighties. They have lived, most of them, in the same houses or apartments for decades. These are not new buildings. They are structures built in the 1930s, 1940s, and 1950s, when the standards governing what was permissible inside the walls of American residential construction were almost nonexistent. Lead paint on every surface. Asbestos in the insulation, the floor tiles, the pipe wrap. Pressed-wood furniture and cabinetry off-gassing formaldehyde continuously into the indoor air. Old plumbing carrying trace heavy metals into the water. And in the basements, in the bathroom grout, behind the wallboard in kitchens where steam condensed for fifty years: mold. The particular, pervasive, immunologically catastrophic mold that colonizes old American housing stock and that, in 1979, virtually no one was measuring or treating or even acknowledging as a health variable.

These men loaded their bags into a van and drove to New Hampshire. They spent a week in a converted monastery surrounded by forest, breathing autumn air laced with compounds their immune systems had not encountered in years. Then they came home.

And for forty years, the story told about what happened during that week has been almost entirely about their minds.

Dr. Ellen Langer, the Harvard psychologist who designed the Counterclockwise Study, built her experiment around the hypothesis that elderly people are constrained not by biology but by self-concept: that if you disrupted their internalized narrative of decline, the body would follow. The results she documented were remarkable: increased grip strength, improved joint flexibility, sharper vision, measurably reduced arthritic inflammation, and photographs that independent observers judged to depict younger men than the before images. The touch football game on the final afternoon became, in the retelling, a symbol of what the mind can do when it stops believing it is old.

The environmental health interpretation of the same data does not dispute the measurements. It disputes the cause. And it begins not in the monastery, but in the houses the men left behind.

What if the experiment’s most important finding wasn’t what the monastery gave these men, but what it temporarily took them away from?

THE INVISIBLE BURDEN: WHAT OLD AMERICAN HOMES DO TO OLD BODIES

The indoor environment of an American home built before 1960 is, by contemporary standards, a substantial toxic exposure. This is not a fringe position. It is the consensus of environmental health science, documented across thousands of peer-reviewed studies and acknowledged by the EPA, the CDC, and every major public health body that has examined the question.

Lead, most visibly. The neurological and cardiovascular effects of chronic low-level lead exposure were not well understood in 1979, but they are now. Lead accumulates in bone over a lifetime and is mobilized back into the bloodstream during aging as bone density declines , meaning an elderly person who was exposed to lead paint in their own home for decades is, in a very literal sense, being slowly poisoned by their own skeleton. Lead disrupts mitochondrial function, elevates systemic inflammation, impairs neuromuscular transmission, and accelerates cardiovascular aging. A study published in JAMA Internal Medicine in 2018 found that blood lead levels in older Americans , even at concentrations well below the levels considered clinically significant , were significantly associated with accelerated biological aging as measured by epigenetic clocks.

Formaldehyde is less discussed but no less consequential. Off-gassing continuously from pressed-wood furniture, particleboard cabinetry, and adhesive materials common in mid-century residential construction, formaldehyde is a potent respiratory irritant and systemic inflammatory trigger. Chronic low-level exposure of the kind produced by sleeping and eating and sitting in the same formaldehyde-emitting environment for twenty or thirty years maintains the body’s inflammatory response in a state of persistent, low-grade activation. This is not acute toxicity. It is something more insidious: a constant background signal telling the immune system that something is wrong, without ever producing a symptom dramatic enough to identify the cause.

And then there is mold. The indoor mycotoxin problem in American housing stock is, according to a growing number of environmental medicine specialists, one of the most underdiagnosed contributors to chronic illness and accelerated aging in older populations. Trichothecene mycotoxins produced by Stachybotrys chartarum , the organism commonly called black mold, prevalent in the damp interiors of aging buildings , are among the most potent biological inflammatory agents identified in any indoor environment. They dysregulate cytokine signaling, suppress natural killer cell function, impair mitochondrial respiration, and produce the particular constellation of symptoms , joint pain, cognitive fog, fatigue, visual disturbance , that characterizes what clinicians now call Chronic Inflammatory Response Syndrome, or CIRS.

“When I look at the symptom profile of the men in Langer’s study, the arthritis, the reduced grip strength, the vision problems, the general physical frailty, I see a clinical picture entirely consistent with chronic mycotoxin exposure,” said Dr. Ritchie Shoemaker, a physician and researcher who has spent more than two decades studying the effects of biotoxin illness in human populations and whose work helped establish the clinical framework for CIRS. “I’m not saying that’s what it was. I’m saying that if you showed me those eight men as patients and told me they all lived in old houses and had been feeling progressively worse for years, mycotoxin exposure would be near the top of my differential. And removing them from those houses for a week would do exactly what Langer described.”

WHAT A WEEK AWAY FROM HOME ACTUALLY DOES TO AN INFLAMED BODY

The immunology here is not complicated, though the popular framing of Langer’s study has never engaged with it. The human inflammatory system is not a fixed state. It is a dynamic response to environmental inputs, and it responds to changes in those inputs relatively quickly. Remove a chronic inflammatory trigger, even briefly, and the body begins to recalibrate. Cytokine profiles shift. C-reactive protein levels fall. The joints, which are among the body’s most sensitive barometers of systemic inflammatory load, begin to decompress.

Seven days. That is how long the men were in New Hampshire. It is long enough to see meaningful inflammatory resolution in someone whose baseline has been chronically elevated by sustained toxic exposure. The arthritic fingers that measurably lengthened as joint swelling subsided are not a mystery if you understand them as the body’s response to the temporary removal of an inflammatory burden. They are what happens when you stop pouring gasoline on a fire.

Dr. Walter Crinnion, a naturopathic physician and researcher who has published extensively on the clinical effects of environmental detoxification, describes the timeline. “The first seventy-two hours away from a chronic exposure source tend to be the most dramatic in terms of measurable inflammatory markers. By day five or six, you can see significant changes in joint mobility, in grip strength, in general energy and cognitive clarity. The visual improvements are interesting. We see those too, because the ciliary muscles and the aqueous dynamics of the eye are sensitive to inflammatory load. When systemic inflammation drops, vision often improves. People think they need new glasses. What they may actually need is to leave their house.”

The men in Langer’s study did leave their houses. For the first time in years, perhaps, their immune systems were not fighting a battle on multiple fronts simultaneously. Their bodies were not processing formaldehyde, mobilizing lead from aging bones, or mounting the low-grade cytokine response that characterizes chronic mycotoxin exposure. They were in the clean, cold air of a New Hampshire forest, eating food prepared in a building with no history of those exposures, sleeping in rooms that were not slowly making them sick.

This is not a small thing. It may, in fact, be the whole thing.

“People think they need new glasses. What they may actually need is to leave their house.”

WHAT THE FOREST WAS ADDING WHILE THE TOXINS WERE ABSENT

The removal of toxic burden is only half the environmental equation. The other half is what the monastery setting was actively providing: a set of biological inputs that urban life had largely stripped from these men’s physiology.

The surrounding New Hampshire forest was, in October, producing a dense aerosol of biogenic volatile organic compounds: primarily the terpene family: alpha-pinene, beta-pinene, limonene, compounds that conifers and deciduous trees emit as a continuous byproduct of their metabolic activity. These phytoncides, as forest medicine researchers call them, are not merely pleasant-smelling background chemistry. They are biologically active agents that, when inhaled, produce measurable and well-characterized changes in human immune function. Qing Li, an immunologist at Nippon Medical School in Tokyo who has conducted the most systematic research into forest bathing physiology, has documented in multiple controlled studies that forest exposure increases the activity and count of natural killer cells, the immune system’s primary anti-cancer and anti-viral defense, and suppresses the production of adrenaline and cortisol. The effect persists for up to a month after the exposure ends.

In men whose NK cell function had been suppressed by years of chronic mycotoxin exposure (mycotoxins are specifically immunosuppressive at the NK cell level), this restoration of immune competence would have had immediate downstream effects on inflammatory regulation. Natural killer cells do not just kill compromised cells. They regulate the broader cytokine environment, sending signals that modulate the entire inflammatory cascade. A week of NK cell restoration, in a body that had been operating with suppressed NK function for years, would look, in the biomarkers Langer collected, exactly like what she saw.

The soil microbiome adds another layer. The forest floor surrounding the monastery harbored the kind of microbial biodiversity that modern urban and suburban environments almost entirely lack. Graham Rook, a professor emeritus of medical microbiology at University College London, has spent decades developing the evidence that chronic inflammatory conditions, from autoimmune disease to the kind of generalized inflammatory aging Langer’s participants exhibited, are substantially driven by the loss of ancestral microbial exposures. The human immune system co-evolved with the organisms in soil and forest air. Deprived of them, it loses its calibration and becomes chronically overactive. Restored to them, even briefly, it begins to settle.

“We are seeing this in clinical practice now with some regularity,” said Dr. Maya Shetreat, a neurologist and herbalist who has written about the intersection of soil microbiology and human health. “Patients with chronic inflammatory conditions who spend sustained time in natural environments , particularly forested ones with rich soil contact , show improvements that we cannot fully explain by any single mechanism. The mycobiome, the bacterial diversity, the phytoncide exposure, the reduction in toxic load: they all operate simultaneously. The body doesn’t experience them separately. It experiences the whole environment at once. And sometimes the whole environment is what it needed.”

THE ELECTROMAGNETIC ARGUMENT

In 1979, the radiofrequency environment of rural New Hampshire was essentially preindustrial. There were no cell towers. The Wi-Fi networks, smart meters, and dense wireless infrastructure that saturate contemporary domestic and urban environments did not exist. The men in the monastery were operating, for a week, in something close to the electromagnetic background that characterized most of human evolutionary history.

The biological significance of this is contested, and it should be stated clearly that the evidence for non-ionizing radiofrequency radiation as a health hazard remains genuinely disputed in the scientific literature. Regulatory agencies in the United States have not established harm thresholds for the exposure levels typical of contemporary environments. A large and serious body of research, however, has documented biological responses to electromagnetic field exposure in cellular and animal models, and a smaller but growing body of human research has raised questions that have not been definitively answered.

What is less contested is the specific mechanism involving the pineal gland. The pineal gland, which synthesizes melatonin in response to darkness and governs the body’s circadian system, is known to be sensitive to magnetic field variations. Multiple studies have documented suppression of melatonin secretion in response to power-frequency electromagnetic field exposure. Melatonin is not simply a sleep hormone: it is one of the body’s most potent endogenous anti-inflammatory and antioxidant molecules. Russel Reiter, a neuroendocrinologist at the University of Texas Health Science Center who has spent four decades studying melatonin’s biological roles, has documented its function as a direct scavenger of hydroxyl radicals, its capacity to upregulate antioxidant enzyme systems, and its inhibitory effects on pro-inflammatory cytokines including TNF-alpha and IL-6. Chronic suppression of melatonin production, by any mechanism, results in elevated oxidative stress, increased inflammatory tone, and accelerated cellular aging.

A week in an electromagnetically quiet rural environment, for men whose pineal glands had been operating in electromagnetic conditions that may have chronically suppressed melatonin output, would have allowed normalized melatonin secretion and overnight repair processes of a depth and quality those bodies had not experienced in years. The downstream effects would be systemic and would include exactly the anti-inflammatory changes Langer’s measurements captured.

This is a hypothesis with incomplete evidence behind it. It is also a hypothesis that, given what we know about melatonin biology, cannot be responsibly dismissed.

THE NOISE PRESCRIPTION

There is one more environmental variable that requires no speculation at all, because the evidence for it is overwhelming: acoustic environment.

Chronic noise exposure, by which environmental health researchers mean the ordinary ambient noise levels of urban and suburban American life in the late twentieth century, is a potent and well-documented driver of inflammatory aging. The mechanism operates primarily through the hypothalamic-pituitary-adrenal axis: sustained noise exposure, even at intensities below conscious discomfort, maintains a low-level activation of the stress response system. Cortisol remains chronically elevated above optimal. The sympathetic nervous system stays partially aroused. Sleep architecture fragments, reducing the depth and duration of slow-wave sleep during which the body performs most of its cellular repair.

A landmark review in The Lancet by Mathias Basner and colleagues documented that noise pollution is, after air pollution, the environmental exposure with the largest quantified burden of disease in developed nations , responsible for a substantial fraction of cardiovascular disease, metabolic dysfunction, and cognitive decline. Elderly populations are disproportionately vulnerable. Their HPA axis regulation is already less robust, their sleep architecture already more fragile, their inflammatory baseline already higher. For an elderly urban resident with decades of accumulated acoustic stress exposure, the effect is not merely inconvenient. It is, in the most literal possible sense, aging them.

The New Hampshire countryside in October 1979 was, by any reasonable measure, among the quietest acoustically characterized environments in the northeastern United States. The men in Langer’s monastery had removed themselves, for seven days, from the primary noise exposure that had been chronically activating their stress response systems for years. Within three to four days of that removal, cortisol diurnal rhythm normalizes measurably. Heart rate variability improves, a sensitive proxy for autonomic nervous system balance and cardiovascular health. Sleep deepens. The overnight repair cascade, allowed to run uninterrupted, begins to address damage that has been accumulating for months or years.

This is not a mysterious process. It is a well-understood one. It simply has never been applied, retrospectively, to the data from a psychology experiment in 1979.

Noise pollution is, after air pollution, the environmental exposure with the largest quantified burden of disease in developed nations. Elderly populations are disproportionately vulnerable. Langer’s men left all of it behind.

WHAT IT MEANS THAT NO ONE ASKED THESE QUESTIONS

The Counterclockwise Study has been in the scientific literature for forty-five years. It has been cited thousands of times. It has shaped popular understanding of aging, mindset, and the plasticity of biological decline. It has generated a substantial research program in the psychology of mindfulness and self-perception. Ellen Langer has been celebrated, rightly, as a creative and important scientist.

And in all of that time, across all of those citations and replications and popular accounts, almost no one has published a serious inquiry into the environmental exposure profile of the setting in which the study was conducted, or the environmental exposure histories of the men who participated in it.

No one has asked what their homes were like. No one has measured the mycotoxin load in the buildings they spent their days in. No one has characterized the indoor air quality of their residences, the lead burden in their blood, the formaldehyde concentrations in their sleeping environments. No one has compared the electromagnetic environment of their neighborhoods to the rural setting of the monastery. No one, in short, has asked whether these men were sick before the experiment began, sick not with aging but with their environments, and whether the monastery worked not by changing their minds but by temporarily extracting them from the sources of their illness.

“The fundamental problem is that environmental medicine and psychology have almost never spoken to each other about the same data,” said Dr. Philip Landrigan, a pediatrician and epidemiologist at Boston College who has spent his career documenting the health effects of environmental toxic exposures. “Psychologists see behavior and cognition. Environmental health researchers see chemical burden and biological response. The Langer study looks completely different depending on which set of eyes you bring to it. What’s frustrating is that the environmental questions are so tractable. We have the tools to answer them. We just haven’t tried.”

The experiment that could settle this question has a straightforward design. Recruit a comparable cohort of elderly individuals. Conduct the full Langer temporal immersion protocol twice: once in the rural monastery setting, and once in an urban setting with equivalent air quality, noise levels, and chemical environment to the participants’ normal residences. Measure, this time, the actual environmental exposures: phytoncide concentrations, microbial biodiversity, indoor air quality, noise levels, electromagnetic field intensity. Measure the biological responses that those exposures produce: NK cell activity, inflammatory cytokine profiles, cortisol diurnal rhythm, melatonin secretion, HRV. If the psychological manipulation is the primary driver, both groups should show similar improvements. If the environment is, the rural group will show effects the urban group does not.

This study does not exist. It should.

THE HOUSES THEY WENT HOME TO

There is one final dimension of this that the psychological interpretation does not address and cannot address, because it has nothing to do with psychology.

The men went home.

They went back to the same houses, the same air, the same slow accumulation of chemical and biological exposures that they had left a week before. And the improvements documented at the end of the monastery week, whatever their cause, did not persist. The follow-up data from the Counterclockwise Study shows that the gains attenuated over subsequent months. The joints stiffened again. The grip strength returned to baseline. The vision reverted.

In the psychological interpretation, this regression is understood as the inevitable reassertion of the self-concept of aging: the men returned to environments that reinforced their old identities, and their bodies followed. This is, again, not an impossible explanation.

But in the environmental interpretation, it is simpler and more stark. They went back to the mold. They went back to the lead and the formaldehyde and the noise and the chemical burden their homes had been generating for decades. The inflammatory cascades that had partially quieted over seven days of forest air and microbial diversity and acoustic quiet resumed their chronic activity. The body responded to its environment, as bodies do, because that is what bodies are designed to do.

The tragedy of the Counterclockwise Study, read this way, is not that the effects were temporary. It is that we spent forty years celebrating the temporary nature of the improvement as a story about the mind, when it may have been a story about housing policy. About toxic building materials. About what we ask elderly Americans to live inside. About the gap between what the human body evolved to inhabit and what it actually inhabits in the last decades of life in contemporary America.

“Aging is partly biological inevitability,” said Dr. Landrigan. “But a significant portion of what we call aging, the inflammation, the joint deterioration, the cognitive decline, the frailty, is environmental disease misclassified as natural decline. We have been treating the normal consequences of toxic exposure as though they were the normal consequences of time. The Langer study, if we read it environmentally, is a brief, accidental window into what these men’s bodies were capable of when you stopped poisoning them. The result was so extraordinary that we invented a psychological explanation for it. Maybe the real explanation is harder to accept, because it implies that we could have done something about it.

The men played touch football. Then they went home. And we told the story as though the football was the point.

Perhaps the point was where they had been standing when they played it.

Selected sources

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Lanphear, B.P. et al. (2018). Low-level lead exposure and mortality in US adults: a population-based cohort study. The Lancet Public Health, 3(4), e177–e184.

Rook, G.A.W. (2013). Regulation of the immune system by biodiversity from the natural environment. Proceedings of the National Academy of Sciences, 110(46), 18360–18367.

Li, Q. et al. (2008). A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins. Journal of Biological Regulators & Homeostatic Agents, 22(1), 45–55.

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Basner, M. et al. (2014). Auditory and non-auditory effects of noise on health. The Lancet, 383(9925), 1325–1332.

Reiter, R.J. et al. (2000). Melatonin as an antioxidant: biochemical mechanisms and pathophysiological implications in humans. Acta Biochimica Polonica, 50(4), 1129–1146.

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Frumkin, H. et al. (2017). Nature contact and human health: a research agenda. Environmental Health Perspectives, 125(7), 075001.

World Health Organization (2011). Burden of Disease from Environmental Noise. WHO Regional Office for Europe.

Landrigan, P.J. et al. (2018). The Lancet Commission on pollution and health. The Lancet, 391(10119), 462–512.

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Langer, E.J. (1989). Mindfulness. Addison-Wesley.

In Morrow County, Oregon, residents began connecting these patterns to something most people never think about: the massive data center that had moved into their community. Officials tested 70 wells. Sixty-eight came back with nitrate levels above federal safety thresholds. When they visited the first 30 homes, they documented at least 25 miscarriages and six people who’d had kidneys removed.

Now, central Ohio residents are asking: Could the same thing be happening here?

The Invisible Infrastructure

Central Ohio has become one of the nation’s densest data center regions. There are 133 facilities across the area, more than half of Ohio’s total, with 28 Amazon data centers alone concentrated near New Albany, Hilliard, and Dublin. These aren’t small operations. A single data center can use millions of gallons of water per day for cooling systems, drawing from the same groundwater supplies that flow into residential wells and municipal water systems.

Most people have no idea these facilities exist in their neighborhoods. They’re designed to be inconspicuous, often resembling warehouses. But their environmental footprint is anything but subtle.

How Data Centers Enter Your Body

The health concerns work through two primary pathways: water and air.

Water contamination happens through a mechanism that’s straightforward but often misunderstood. Data centers don’t add nitrates to water; they accelerate existing contamination. Central Ohio’s agricultural legacy left nitrogen-based fertilizers in the soil. Under normal conditions, groundwater movement allows time for natural filtration. But when data centers pull massive volumes of water from underground aquifers, they create pressure changes that can cause nitrate-laden water to seep into the supply faster than it can be filtered.

Nitrates in drinking water interfere with oxygen transport in the blood. In pregnant women, this can lead to miscarriage or developmental problems. In children, it causes “blue baby syndrome,” where tissues don’t get enough oxygen. In adults, chronic exposure is linked to thyroid problems and certain cancers, particularly of the digestive system.

Air pollution adds another layer. A Caltech study found that data centers’ emissions are expected to contribute to 1,300 premature deaths annually in the U.S. by 2030, creating a public health burden approaching $20 billion. The facilities emit nitrogen oxides and particulate matter from backup diesel generators and cooling systems. These pollutants aggravate asthma, contribute to cardiovascular disease, and increase susceptibility to respiratory infections.

If someone in your household has persistent breathing problems that doctors attribute to “seasonal allergies” or “stress-induced asthma,” the data center three miles away may be a variable no one has checked.

The Symptoms No One Connects

This is where environmental health impacts become invisible. A woman has a miscarriage and is told it’s common, just bad luck. A man in his forties develops kidney problems and doctors point to diet or genetics. A child’s asthma gets worse every year and parents are advised to reduce household allergens.

These explanations aren’t wrong; they’re incomplete. Location is almost never part of the diagnostic conversation. Doctors don’t typically ask: “What’s the industrial infrastructure near your home? Where does your water come from? Are there new facilities that have opened in your area in the past five years?”

The Ohio EPA’s Central Ohio Regional Water Study shows correlation between areas with the worst water quality and data center concentrations, though officials say there isn’t enough data yet for definitive causation. That phrase, “not enough data,” is common in environmental health. It often means the monitoring hasn’t been done, not that the risk isn’t real.

The Regulatory Gap

Ohio is currently considering a new permit specifically for data centers that discharge wastewater and stormwater. The draft permit would allow facilities to release certain wastewater with fewer pollutants into nearby water sources. Notably, the list of banned pollutants does not include nitrates.

The permit’s language is revealing: it states that “a lowering of water quality of various waters of the state is necessary to accommodate important social and economic development.” This is the calculus being made: water quality traded for economic growth, with the assumption that the health costs will remain diffuse enough to avoid accountability.

Amazon disputes any connection between its facilities and health problems, calling recent reports “misleading and inaccurate.” The company notes that data centers draw from the same water supply as everyone else and that nitrates come from agricultural sources, not data center operations. This is technically true. But it sidesteps the question of whether the facilities’ water demands are accelerating the movement of existing contaminants into drinking water supplies.

What Central Ohio Residents Are Seeing

Dublin resident and data center activist Amy Swank has been pushing for greater public awareness. “There is a lack of understanding and a need for education,” she said. “What these really do, how they really impact our electricity, our water, our community noise pollution level, light pollution level, and then what are the economic benefits to having one? I don’t think people truly grasp that.”

The impacts accumulate slowly. A family notices their well water tastes different. Neighbors start comparing health notes and realize several households have similar problems. Someone files a water quality complaint, but testing is delayed or incomplete. By the time patterns become undeniable, years have passed and health damage is already done.

Awareness as Infrastructure

Some data center operators are beginning to shift practices. Amazon recently announced that 120 of its facilities will switch to recycled water from wastewater treatment plants rather than drawing from fresh drinking water supplies. Whether this happens in Ohio, and whether it’s enough, remains to be seen.

The Ohio EPA is accepting public comments on the data center permit proposal through December 17. This is one of the rare moments when residents can formally weigh in on regulatory decisions that will shape their water quality for years to come.

But beyond permits and corporate pledges, there’s a simpler need: people who live near these facilities need to know they exist, understand what they do, and recognize that unexplained health patterns in their community may have an environmental source. That awareness doesn’t require advanced degrees or political mobilization; it just requires asking the question.

If you live in central Ohio, you probably live within a few miles of a data center. Your water comes from the same aquifer these facilities draw from. Your air carries the same emissions. And when your body reacts, when you’re tired all the time, when your child can’t breathe easily, when your pregnancy ends without explanation, there may be a reason beyond bad luck or genetic predisposition.

This is not about fear. It is about understanding how the places we live shape our health, often in ways we are never told.

Join our Facebook group to connect with others exploring how location affects health:
https://www.facebook.com/groups/locationeffect

Iowa now occupies an unenviable distinction in American public health: second only to Kentucky in overall cancer incidence. Between 2015 and 2019, as cancer rates stabilized or declined across the remainder of the United States, Iowa’s trajectory diverged upward. In certain agricultural counties, cancer incidence exceeds the national baseline by 50 percent. The malignancies span diverse organ systems: oral cancer, leukemia, non-Hodgkin lymphoma, melanoma, and cancers of the kidney, colon, and breast. This is a spectrum of malignancies that suggests broad environmental exposure rather than any single cause.

The Agricultural Transformation

Iowa’s contemporary landscape bears little resemblance to the diversified farms of previous generations. Today, approximately 85 percent of the state functions as an industrial monoculture devoted primarily to corn and soybean production. This transformation has been underwritten by unprecedented applications of synthetic inputs: nitrogen fertilizers measured in millions of tons annually, herbicides applied across virtually every cultivated acre, and pesticides deployed on schedules dictated by agronomic efficiency rather than toxicological prudence.

The public health consequences emerge through two primary exposure pathways, each creating opportunities for chronic, low-level contact that accumulates over years and decades.

Contaminated Water Systems

Agricultural runoff has fundamentally altered Iowa’s hydrological chemistry. Nitrate concentrations in groundwater have risen in direct proportion to fertilizer applications, with approximately 18 percent of private rural wells now exceeding the Environmental Protection Agency’s maximum contaminant level. An additional 37 percent surpass half that threshold. These figures, derived from surveys conducted in the late 1980s, represent a baseline that has only deteriorated with agricultural intensification.

The biochemical pathway from nitrate exposure to carcinogenesis is well-established. Following ingestion, commensal gut bacteria reduce nitrates to nitrites through normal metabolic processes. These nitrites subsequently react with dietary amines to generate N-nitroso compounds, a class of potent carcinogens capable of systemic distribution and DNA intercalation. The University of Iowa’s landmark 2001 study tracking more than 20,000 women demonstrated dose-dependent relationships between drinking water nitrate levels and elevated risks of bladder and ovarian cancers, controlling for confounding lifestyle variables.

Atmospheric Dispersion

Agricultural pesticides exhibit mobility far exceeding their intended application zones. Volatilization from treated surfaces, aerial drift during application, and wind-driven transport can distribute these compounds across distances measured in miles rather than feet. Consequently, exposure extends well beyond farm boundaries to encompass suburban developments, exurban residential areas, and small municipalities situated within agricultural regions.

Contemporary environmental monitoring reveals pesticide residues in more than 90 percent of Iowa water samples. Air quality studies document measurable concentrations at substantial distances from application sites. Soil analyses demonstrate persistence measured in decades, while biomonitoring studies confirm accumulation in adipose tissue, creating endogenous exposure reservoirs that continue releasing compounds long after external contact has ceased.

Biological Mechanisms

The health effects manifest across temporal scales. Acute exposures, particularly during intensive application periods, can precipitate immediate physiological responses: inflammatory cascades in respiratory epithelium, cutaneous hypersensitivity reactions, cephalgia, gastrointestinal dysfunction, and neurocognitive symptoms including concentration deficits and executive function impairment. These presentations are frequently misattributed to seasonal allergies, psychosocial stress, or nonspecific viral syndromes.

The chronic sequelae prove more consequential. Many agricultural chemicals demonstrate genotoxic properties. They induce direct DNA strand breaks, interfere with nucleotide excision repair pathways, and allow mutagenic lesions to evade cellular surveillance mechanisms. They generate reactive oxygen species that overwhelm endogenous antioxidant systems, producing oxidative damage across multiple tissue types. They function as endocrine disruptors, mimicking or antagonizing hormonal signaling. They suppress adaptive immune responses, compromising tumor immunosurveillance. They alter the intestinal microbiome, disrupting both immune homeostasis and xenobiotic metabolism.

Certain populations face disproportionate vulnerability. Pediatric exposure occurs during critical developmental windows when organogenesis remains incomplete and detoxification capacity is immature. Pregnant women confront risks extending to fetal development. Agricultural workers sustain the highest direct exposures. The elderly and immunocompromised possess diminished capacity for damage repair and toxin clearance.

Individuals with chemical sensitivity syndromes report that cumulative toxic burden exacerbates multiple chemical sensitivity, chronic fatigue syndrome, autoimmune conditions, and respiratory disorders. A consistent observation emerges from patient histories: symptomatic improvement following relocation away from intensive agricultural areas. This geographic specificity implicates environmental rather than idiopathic etiologies.

Diagnostic Blind Spots

Contemporary medical training emphasizes individual pathophysiology while systematically underweighting environmental determinants of disease. Physicians presented with the symptom complexes described above typically pursue conventional differential diagnoses: anxiety disorders, depression, chronic stress, age-related decline, or primary lifestyle factors. Environmental exposure rarely appears in the standard diagnostic algorithm.

The temporal characteristics of these exposures compound diagnostic difficulty. Carcinogenesis proceeds across years or decades, severing the temporal link between exposure and outcome. By the time malignancy manifests, the causal chain has been obscured by intervening time. Only population-level epidemiological analyses reveal patterns invisible at the individual patient level.

Regulatory Inadequacy

Iowa’s cancer burden represents not random misfortune but predictable consequences of systematic regulatory failure. The federal pesticide registration process relies predominantly on industry-funded studies. Long-term human health assessments are not prerequisite to market approval. Enforcement mechanisms prove episodic and penalties insufficient to modify corporate behavior. State agencies default to federal standards that frequently lag scientific evidence by decades.

Structural conflicts of interest pervade the regulatory apparatus. Chemical manufacturers provide substantial funding to regulatory agencies through user fees, creating financial dependencies. Industry advocacy organizations maintain lobbying expenditures exceeding public health advocates by an order of magnitude. Personnel flows between regulatory positions and industry employment create networks of aligned interests.

The distribution of harm follows predictable patterns of environmental injustice. Rural communities sustain the exposure burden while profits accrue to distant corporate entities. Children consume contaminated water. Families inhale pesticide-laden air. Cancer patients face financial devastation treating diseases with clear environmental contributors.

The Value of Recognition

Understanding location as a health determinant creates decision points previously obscured. Individuals contemplating relocation to Iowa’s agricultural regions are, whether consciously or not, accepting documented environmental health risks. The pastoral aesthetics of farmland mask measurable disease burdens.

Current residents, armed with this recognition, can implement protective strategies: comprehensive water testing, installation of appropriate filtration systems, temporal tracking of spraying schedules, documentation of unexplained symptoms, and informed evaluation of whether continued residence aligns with individual health priorities.

This analysis does not advocate panic but rather clear-eyed assessment. Iowa’s divergent cancer trajectory is neither mysterious nor inevitable. It reflects decades of agricultural practices prioritizing yield maximization over population health, enabled by regulatory structures that have abdicated their protective mandate.

Recognition precedes response. Iowa’s agricultural landscape has been converted into an uncontrolled experiment in chronic chemical exposure, with outcomes measured in cancer registries, chronic disease prevalence, and preventable mortality. This trajectory is neither sustainable nor acceptable. It constitutes a crisis requiring acknowledgment before remediation becomes possible.

Together, we can make our presence visible and impossible to ignore. Join our pesticide sensitivity map:

https://www.planethealthproject.org/pesticidesensitivitymap