A new study published in Risk Analysis found that residents living within five miles of the former Santa Susana Field Laboratory reported autoimmune disorders at more than four times the rate of those living 11 to 15 miles away.
Researchers from the University of Southern California led the study, shifting focus beyond the cancer statistics that have dominated discussion of the site for years. Instead, they examined health conditions and protective behavior among residents of a higher-income community living near a contaminated site, rather than the lower-income communities typically studied in environmental risk research.
An Unused Meltdown Superfund
Located in the Simi Hills northwest of Los Angeles, the Santa Susana Field Laboratory hosted rocket engine testing from 1949 to 2006 and nuclear reactor operations from 1953 to 1980. In 1959, a partial meltdown occurred at the site, which later became associated with radioactive and chemical contamination in soil and groundwater both on and beyond the property. Some have described the accident as the worst nuclear accident in U.S. history.
Although SSFL was designated a Superfund-eligible site in 1989, it has never been added to the National Priorities List. As a result, the site has not been cleaned up through the standard federal Superfund process.
Previous health studies did not find a significant increase in most cancers among those who lived near the site. A 1992 California Department of Health Services report also concluded that people living near SSFL were not at increased risk of developing cancers associated with radiation exposure. However, many residents and advocacy groups still believe that contamination from the Santa Susana Field Laboratory may be negatively impacting community health.
Testing What Money Can and Can’t Buy
Most Superfund sites are located in low-income areas, with 62% of nearby households earning less than $50,000 a year nationwide. The Santa Susana Field Laboratory is different, as it is surrounded by higher-income neighborhoods. This gave the USC team an opportunity to examine how residents with greater financial resources respond to environmental hazards in their community.
Led by Jenna Blyler of the USC Wrigley Institute for Environment and Sustainability, the team surveyed 475 residents living within 15 miles of the site. More than half (56%) reported household incomes of $100,000 or more.
Illness That Tracks With Distance
The study found that 18% of residents living within five miles of the Santa Susana Field Laboratory reported autoimmune disorders, as compared to 4% of those living between 11 and 15 miles from it. Similarly, 15% of residents living within five miles reported metabolic and endocrine disorders, compared with 2% of those living 11 to 15 miles away.
Over one third of residents said they had received at least one chronic diagnosis since moving to the area, a rate similar to the national average of 38%. This result is notable because chronic illness is usually less common in higher-income communities.
Fear as a Motivator
“We expected to see wealthier people take more actions to protect themselves given their greater capacity to cope and affect change,” Blyler said. “Instead, fear of the contamination was what motivated protective action, rather than their perceived ability to manage the risks.”
The study also found that residents were more likely to adopt protective measures if they believed those measures were expensive. The finding runs counter to the researchers’ expectations and to previous research suggesting that higher costs can discourage protective behavior.
Blyler and her coauthor, Joseph Árvai, suggest two possible reasons for this result. The community may be able to afford costs that would prevent other groups from taking action, or residents may see a higher price as a sign that a precaution is effective and worth the investment.
What the Study Can’t Answer
The authors note several limitations of the study. The research is based on self-reported diagnoses collected at one point in time, and it does not show that contamination from the Santa Susana Field Laboratory directly caused the health conditions residents reported.
The researchers also found that health anxiety partially explained the relationship between existing illness and protective behavior, but the study could not determine why certain conditions were more frequently reported closer to SSFL.
Future studies using objective health data and longer-term follow-up could help determine whether the reported patterns reflect actual differences in disease prevalence and whether environmental exposure plays a role.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.