The research team, a collaboration between the university’s Department of Psychology and the Mel and Enid Zuckerman College of Public Health, surveyed 363 people across Tucson’s south side and a carefully matched comparison neighborhood. Among participants who lived, worked, or attended school in the contaminated area before 1981, or whose parents did, 34 percent reported enough symptoms to cross a screening threshold that clinicians routinely use to flag probable post-traumatic stress disorder. That figure was drawn from a seven-item checklist asking respondents whether worry about the contamination had produced specific experiences during the past month, including avoiding places that brought the contamination to mind, sleeping poorly, or feeling cut off and detached from other people. Reporting four or more of the seven criteria was treated as the threshold for further clinical attention.

The study was led by Harrison Schmitt, who carried out the work as his doctoral dissertation at the University of Arizona and is now an assistant professor of psychology at Skidmore College. Daniel Sullivan, the study’s senior author and an associate professor in the Department of Psychology, said the persistence of the effect was the most startling element of the results. “It was pretty striking how long the impact of this seems to have been,” Sullivan said. For a community whose exposure officially ended when the city stopped serving contaminated water on its south side in 1981, the survival of trauma symptoms across four decades suggests that environmental contamination can function not merely as a past event but as an ongoing, inherited burden carried through families and neighborhoods.

To contextualize the magnitude of that burden, Sullivan’s team administered the same screening instrument in 2025 to Los Angeles residents whose homes were threatened by wildfires, a group experiencing an acute, vivid, and recent disaster. Roughly 35 percent of those respondents scored at or above the PTSD screening threshold, a figure nearly identical to the rate found among Tucson’s south side residents remembering exposures that ended generations ago. The parallel is consequential for the field of disaster psychology, which has historically calibrated its expectations around discrete, cinematic catastrophes such as tornadoes, floods, and fires. Sullivan, who studied tornado survivors in Kansas for his own dissertation, has long argued that technological disasters deserve separate theoretical treatment because they unfold over years, lack a single identifiable day of damage, and often involve prolonged institutional silence or denial about what occurred.

Before the survey was even designed, Sullivan spent years attending community meetings on Tucson’s south side, an investment in local trust that shaped every subsequent stage of the project. Beginning in the summer of 2022, approximately twenty undergraduate volunteers collected the survey door to door in pairs, with each pair including at least one bilingual student so that questionnaires could be offered in both English and Spanish. The ground-level method produced insights that no mailed questionnaire could capture. Many of the volunteers came from the south side themselves, and several learned in the course of their canvassing that their own relatives and neighbors had lived through the contamination and had rarely, if ever, spoken about it. The data collection thus doubled as an act of oral history, surfacing family silences that had persisted alongside the symptoms the survey was designed to measure.

A critical methodological safeguard was the construction of a comparison group. The researchers deliberately selected a second Tucson neighborhood matched to the south side on income, race and ethnicity, and housing characteristics, ensuring that differences in trauma symptom rates could be attributed to the contamination itself rather than to the chronic socioeconomic stressors both areas share. This design choice strengthens the study’s central inference considerably. Residents of the matched neighborhood face comparable economic pressure, comparable discrimination, and comparable housing instability, yet they did not carry the same psychological load, pointing to the contaminated water as the decisive distinguishing exposure.

Elizabeth Yee, a co-author and Ph.D. student in psychology who first worked on the survey as an undergraduate and later led the effort to report the findings back to residents, described the emotional texture of the canvassing work. “You’re talking to people and it’s every other house. At a community level, the findings are validating. At an institutional level, it still feels like, ‘When is it going to be enough evidence to act?'” she said. Her remark captures a tension running through the entire research program: the same data that affirms residents’ lived experience also documents how slowly institutional recognition has moved relative to the scale of harm. The researchers describe the pattern they uncovered as collective trauma, a framework in which a devastating event is shared across a community and transmitted through common experiences and stories rather than being experienced and processed only as individual psychological injury.

The study’s community-facing dimension owes much to Alisha Vasquez, a disability cultures folklorist at the Southwest Folklife Alliance and a co-director of Tucson’s Mexican American Heritage and History Museum. Vasquez helped connect the research team with south side residents and convened a community meeting that shaped how the survey results are now being deployed for political action. “They fought their entire lives, not just for restitution, but to be heard and believed,” Vasquez said. Her framing underscores a theme that quantifies poorly but matters enormously in the epidemiology of environmental injustice: the harm of contamination compounds when survivors’ accounts are dismissed, and part of the healing process involves official acknowledgment that the harm was real. In December 2025, a memorial honoring the victims of the historic contamination was unveiled in Mission Manor Park as part of Vasquez’s community-based arts initiatives on the topic, a physical landmark for a history that many families had carried silently.

The research has already moved beyond the pages of an academic journal. Working with Vasquez and other community activists, the research team has presented its findings to Tucson Water, the Environmental Protection Agency, and the Tucson Mayor and Council. The City Council responded by passing a resolution urging the Pima County Health Department to address the impacts of the contamination, converting a psychological survey into an instrument of municipal policy. For the researchers, that trajectory reflects the specific history of the place rather than a novelty. “Tucson was a historic leader in fighting for recognition of these issues,” Sullivan said. “This is a community with a lot of resilience.” The authors declared no potential conflicts of interest with respect to the research, its authorship, or its publication.

The scientific implications of the study extend well beyond southern Arizona. As climate-driven wildfires, industrial accidents, and aging water infrastructure expose growing populations to environmental threats, the Tucson findings suggest that the mental health consequences of such events may be measured in generations rather than news cycles. A screening threshold crossed by one in three exposed residents forty years after the fact implies that standard disaster-response timelines, which concentrate psychological services in the weeks and months following an acute event, are poorly matched to slow-onset technological disasters. The Tucson study offers both a warning and a template: the warning that contamination quietly externalizes its costs onto community mental health for decades, and the template that door-to-door, bilingual, community-partnered research can document those costs with enough rigor and legitimacy to compel institutional response.

Subject of Research: Long-term psychological trauma among residents exposed to historical water contamination in Tucson

Article Title: One in three Tucsonans exposed to historic water contamination still report signs of psychological trauma

Article References: One in three Tucsonans exposed to historic water contamination still report signs of psychological trauma. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Tucson, water contamination, PTSD, collective trauma, environmental injustice, groundwater, industrial solvents, public health, Journal of Health Psychology, community-based research, disaster psychology, University of Arizona