Chronic Illness Climbs Closer to a Former Nuclear Site in California

EMBARGOED UNTIL August 26, 2026 @ 8:00 a.m.

Residents within five miles of the Santa Susana Field Laboratory report elevated autoimmune and endocrine disorders, new research in Risk Analysis finds August 26, 2026 (Herndon, VA) — Superfund sites typically cluster in low-income

communities, where 62% of households earn less than $50,000 annually. But near the Santa Susana Field Laboratory in the hills northwest of Los Angeles people are much wealthier. This anomaly gave University of Southern California researchers an opportunity to study how wealthy residents respond when money cannot buy their protection from an environmental hazard.

Rocket testing (1949–2006) and nuclear reactor operations (1953–1980) left radioactive and chemical waste in the soil and groundwater at SSFL. A 1959 partial meltdown, considered the worst in U.S. history, contaminated both on- and off-site areas. And despite Superfund eligibility since 2007, the site remains un-listed on the National Priorities List, which means that any form of remediation is managed at the state and local levels.

Early investigations at SSFL found no significant increases in most cancers of concern, though bladder, blood and thyroid cancers were linked to living closer to the facility. Although there were significant data limitations, a 1992 state health report found cancer rates inconsistent with community-wide exposure. Despite the absence of definitive epidemiological evidence, many residents and advocacy organizations remain convinced that SSFL contamination has adversely affected community health.

This forthcoming research, published in Risk Analysis, aimed to answer three questions previous research had left unanswered. First, does health risk extend beyond the cancers typically studied, and does it scale with proximity to the site? Second, how do wealthier groups perceive and respond to environmental health risks? Third, do the residents in this sample area perceive and respond to contamination risk as predicted by Protection Motivation Theory, or do their responses differ?

In this study, researchers at USC surveyed 475 residents living within 15 miles (24 kilometers) of SSFL. Of the population sampled, 56% earned $100,00 or more annually. “We expected to see wealthier people take more actions to protect themselves given their greater capacity to cope and affect change,” said lead author Jenna Blyler of the USC Wrigley Institute for Environment and Sustainability. “Instead, fear of the contamination was what motivated protective action, rather than their perceived ability to manage the risks. ”

Key Findings

• Illness tracked with proximity. Autoimmune disorders were reported by 18% of residents living within five miles of SSFL, compared with 4% of those 11 to 15 miles out. Metabolic and endocrine disorders followed the same pattern, 15% versus 2%.
• More than a third of residents reported at least one chronic diagnosis since moving in. That is on par with the national rate of 38%, even though chronic illness is normally far less common in high-income communities.
• Fear drove action more than confidence did. Residents who saw the contamination as severe and felt personally vulnerable were the most likely to take precautions, such as filtering tap water, leaving shoes at the door, skipping garden produce or staying inside on windy days. Usually, one’s confidence in their ability to effectively manage its risk also creates a powerful motivation to act.
• Health anxiety helped explain the pattern. Residents reporting higher health anxiety took more precautions, and anxiety accounted for part of the link between existing illnesses and protective behavior.
• The more expensive residents believed protection would be, the more of it they took. That runs counter to decades of risk research. It may reflect a community that can absorb the cost, or one that reads a higher price tag as a sign that something is effective.

The study is based on self-reported diagnoses collected at a single point in time and does not establish that SSFL contamination caused the health conditions residents reported.

Authors Available for Interview

Jenna Blyler, corresponding author, Wrigley Institute for Environment and Sustainability and Department of Psychology, University of Southern California.

Joseph Árvai, Wrigley Institute for Environment and Sustainability, Department of Psychology, University of Southern California, and Decision Research.

“Silver spoons in toxic soups: Predictors of protective action in affluent neighborhoods near a contaminated research facility,” Risk Analysis

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About Risk Analysis

Risk Analysis is a peer-reviewed journal publishing original research on the assessment and management of risks across disciplines including public health, engineering, environmental science, social science and policy. Risk Analysis, founded in 1980, is published by Wiley on behalf of the Society for Risk Analysis.

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