01
May
Exposure to Toxic Chemicals, including Pesticides, Tied to Adverse Mental Health in Military Service Members
(Beyond Pesticides, May 1, 2026) A study in Psychiatry Research, entitled “Toxic Exposure and Rates of Suicidal Thoughts and Behaviors Among U.S. Military Veterans,†adds to the body of science linking poorer mental health among military members with exposure to environmental contaminants. While previous research focuses on mental health broadly, the current observational cohort study focuses on exposure to toxic substances and suicidal thoughts and behaviors (STBs) through the analysis of data from 248,926 U.S. veterans enrolled in the Million Veteran Program (MVP). In comparing self-reported exposures to nine toxicants, including Agent Orange, chemical/biological weapons, anthrax vaccine, solvents/fuels, petroleum combustion products, lead, other metals, pesticides, and open-air burn pits, and mental health records, the researchers find that military veterans with higher toxic exposures are more likely to have STBs.
The authors also report that these associations occur across all major service cohorts (pre-Vietnam, Vietnam, post-Vietnam, Gulf War, and post-9/11 eras). “Our work contributes to growing evidence that veterans who report more toxic exposures are more likely to have STBs, consistent with greater risk for other mental health outcomes (e.g., depression, PTSD [post-traumatic stress disorder]),†the researchers conclude.
Importance and Background
Military members experience increased health risks with exposure to environmental contaminants, such as pesticides. This occupational exposure is similar to the increased risks associated with farmers and farmworkers, as well as vulnerable communities, who experience disproportionate risks. As Beyond Pesticides shares, pesticide exposure itself does not discriminate, as these toxic chemicals impact the health of all men, women, and children alike. However, pesticide exposure patterns tend to cause elevated rates of health disparities and disorders. (See Daily News coverage on disproportionate risks here.)
Disproportionate military exposure to environmental toxicants remains consistent over different eras of military service and geographic locations while the specific compounds vary. “For example, service during Vietnam included possible exposure to the chemical herbicide Agent Orange, whereas later operations in Iraq, Afghanistan, and Kuwait included risk for exposure to open air burn pits and other airborne hazards,†the authors note. (See study here.) They continue: “Acknowledgement of these exposures and the health risks that accompanied them resulted in the 2022 Sergeant First Class Heath Robinson Honoring our Promise to Address Comprehensive Toxics (PACT) Act. The PACT Act established mandatory exposure screening and coverage of illnesses presumed to be associated with toxins and increased the number of veterans eligible to receive covered care through the Department of Veteran’s Affairs (VA) health care systems.†(See Beyond Pesticides’ coverage of the PACT Act here.)
Evidence linking exposure to environmental contaminants and poorer mental health continues to mount, as this study points to the lack of research on military veterans and STBs prior to this research. “Other mental health disorders, such as depression and posttraumatic stress disorder (PTSD), are more prevalent among veterans with toxic exposure and associated with greater risk for STBs,†the researchers state. “For example, a recent study found that post-9/11 veterans who reported more toxic exposure had worsening mental health symptoms over the next decade, suggesting that risk for STBs among veterans with toxic exposure might increase over time.†(See studies here, here, and here.)
Methodology and Results
Using data from the 248,926 veterans in the MVP cohort, this study links self-reported toxic exposure to an increased risk of suicidal thoughts and behaviors. “We also examined whether associations varied by service era and specific toxic exposure type, the rate of exposure for specific toxins, the categories of STBs, and the extent to which the associations might reflect a broader association between toxic exposure and mental health by accounting for PTSD and depressive symptoms,†the authors explain.
Electronic medical records were used to confirm the history of STBs in veterans, which includes suicidal ideation, suicide attempt, or death by suicide. In total, the data reveals 32,931 participants (13.2%) with STBs. As a result, veterans who reported more toxic exposures are more likely to have STBs, with “a 7.2% increased risk of STBs for each additional toxic exposure a veteran reports.†The statistical analysis shows that each additional toxic exposure translated “to a 0.7% increase in the absolute risk and a 5.9% increase in the relative risk of having STBs.â€
In summary, the researchers state, “Our findings contribute to a growing literature linking toxic exposures to negative mental health outcomes, particularly among military veterans.†They continue, “[I]ncreased rates of STBs associated with toxic exposure could be interpreted as a global increase in risk for negative mental health outcomes among individuals reporting more toxic exposure. This interpretation is supported by the results for the specific categories of STBs, which showed the association between toxic exposure and STBs was largely explained by higher rates of suicidal ideation. Taken together, these results suggest higher risk for STBs among veterans with toxic exposures are likely to be accompanied by mental health diagnoses, such as depression and PTSD (and vice versa).”
Previous Coverage
In recent comments to the Department of Veterans Affairs regarding the plan to conduct an assessment of scientific literature and historical claims data as it relates to military environmental exposure and neurodegenerative outcomes, Beyond Pesticides continues to advocate for the recognition of disproportionate risks to service members and the transition to safer alternatives. Exposure to environmental contaminants, such as pesticides, asbestos, industrial solvents, smoke and toxic fumes, lead, fuel, polychlorinated biphenyls (PCBs), and per- and poly-fluoroalkyl substances (PFAS), occurs through various activities. The inhalation, ingestion, and dermal absorption of these dangerous compounds take place during deployment and training, both on and off base, as service members encounter burn pits, airborne dust and fumes from chemical warfare agents or pesticide applications, and contaminated food and drinking water. Pesticide-treated uniforms are also a direct source of dermal exposure, particularly as sweat in field conditions increases absorption. (See studies here and here.)
Unfortunately, the majority of research connects military exposure to adverse health effects many years or decades after exposure has occurred. One study, published in JAMA Neurology, connects military service to increased risks of Parkinson’s, finding that the disease incidence was 70% higher in Camp Lejeune veterans (stationed there during 1975-1985) as compared with veterans stationed at a Marine Corps base where water was not contaminated with trichloroethylene and other volatile organic compounds.
A wide body of research continues to mount on Gulf War Illness (also known as Gulf War Syndrome). One previous report shows that at least one in four of the 697,000 U.S. veterans of the 1991 Gulf War suffer from Gulf War illness, a condition caused by exposure to toxic chemicals, including pesticides. In the report, a federal panel of scientific experts and veterans on the Congressionally-mandated Research Advisory Committee on Gulf War Veterans’ Illnesses said, “The extensive body of scientific research now available consistently indicates that Gulf War illness is real, that it is the result of neurotoxic exposures during Gulf War deployment, and that few veterans have recovered or substantially improved with time.†The 450-page report was a landmark study that brough together for the first time the full range of scientific research and government investigations on Gulf War illness. (See Daily News here.)
Additional scientific literature connects exposure to “rainbow herbicides,†particularly Agent Orange, used during the Vietnam War to significant health impacts. Agent Orange contained significant amounts of the synthetic contaminant dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin), often called TCDD. Dioxins are highly toxic chemicals that persist for years in the environment (especially in soils, lake and river sediments, and the food chain) and accumulate in fatty tissues of animals. Dioxins are carcinogenic, toxic even at very low exposure levels, and responsible for both acute and long-term effects. They have been proven to cause not only cancer, but also, other grave health problems, such as birth defects, extreme rashes, and severe neurological and psychological issues. Research finds that U.S. war veterans exposed to Agent Orange developed chronic lymphocytic leukemia, Hodgkin’s disease and non-Hodgkin’s lymphoma, prostate cancer, Parkinson’s disease, and diabetes. Many children of exposed veterans have also been affected by their parents’ exposure to the chemical and show a wide range of symptoms, highlighting the multigenerational effects of this exposure.
Research on pesticide-treated uniforms has established a link to Parkinson’s as well. Multiple studies, including those published in the Journal of Exposure Science & Environmental Epidemiology, Toxicology Letters, International Journal of Hygiene and Environmental Health, and Journal of Exposure Science & Environmental Epidemiology, show increased exposure to military service members to the synthetic pyrethroid permethrin through their uniforms. Permethrin exposure can cause neurotoxicity, carcinogenicity, and organ damage, among others, and is particularly linked to Parkinson’s. A JAMA Neurology study found that the risk of Parkinsonism doubled with increased occupational exposure to pesticides. Permethrin was associated with a more than three-fold increased risk of Parkinson’s disease. (See Daily News here.)
Aside from neurodegenerative effects, such as with Parkinson’s, military exposure is linked to other neurological implications, including poorer mental health outcomes outlined in the current study and additional research. A review, written by medical professionals and researchers throughout the U.S. and published in Medical Care, analyzed the existing literature on associations between military environmental exposures to contaminants, including pesticides, and mental health outcomes. The 49 studies in the review, covering chemical exposures for military members, involve chemical munitions from the Gulf War era and Agent Orange from the Vietnam War era that are associated with symptoms of depression, PTSD, and anxiety, among others. (See Daily News here.)
The Organic Solution
The evidence is clear that neurological impacts are disproportionately present in military service members. The solution to these disproportionate risks for military service members lies in systems-based, holistic change. Whether in the military, commercial agriculture, or home gardens, toxic pesticides and other environmental contaminants have no place. The threats to the health of entire ecosystems, wildlife, and humans are unreasonable, especially given available alternatives such as organic land management.
In adopting organic standards, which are continuously improved upon through the National Organic Standards Board (NOSB), all life can be protected. Learn more about the Spring 2026 NOSB meeting, which will be held in Omaha, NE, and available virtually, May 12-14, through the Keeping Organic Strong resource page. A draft meeting agenda is available HERE. And a detailed agenda, along with the proposals, is available HERE. Written comments are due by 11:59 pm ET Monday, May 4, 2026. Beyond Pesticides launched an action to encourage public engagement with the NOSB public comment period. Click here to see and participate in the action.
Additional information about the health and environmental benefits of organic methods can be found here and here. Have your voice heard by participating in Action of the Week, which is intended to provide you, our supporters and network, with one concrete action that you can take each week regarding governmental actions that are harmful to the environment and public and worker health, increase overall pesticide use, or undermine the advancement of organic, sustainable, and regenerative practices and policies.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
Bourassa, K. et al. (2026) Toxic Exposure and Rates of Suicidal Thoughts and Behaviors Among U.S. Military Veterans, Psychiatry Research. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0165178126002337.
