Residents living within 8 kilometers of the former Santa Susana Field Laboratory (SSFL) in California reported autoimmune diseases at a rate of 18%, compared with just 4% among those living 18 to 24 kilometers away, according to a new study from a University of Southern California (USC) research team.
The same pattern appeared for endocrine and metabolic disorders, which affected 15% of people living closer to the site versus 2% of those farther away. The findings come from a survey of 475 people living within 24 kilometers of the facility.
The Santa Susana Field Laboratory sits northwest of Los Angeles and was used for nearly 60 years to test rocket engines and operate nuclear reactors. In 1959, the site experienced a partial reactor meltdown, and it has since been associated with radioactive and chemical contamination of the surrounding soil and groundwater.
Shift From Cancer Research
Earlier studies of the area mainly looked for links to cancer and largely found no significant increase in most cancer types among nearby residents. The new research instead examines chronic illness and how people respond to a perceived environmental threat.
Income Was Not the Deciding Factor
The study group stood out for its makeup: 56% of participants reported a household income of at least $100,000 a year. The researchers set out to understand how residents of a relatively affluent area take precautions against contamination. They found that financial means was not the main driver of protective behavior. Instead, people were more likely to take precautions when they felt a stronger sense of threat from potential contamination.
Study Has Limits
The researchers cautioned that the study cannot establish whether the higher rate of diagnoses was actually caused by exposure to SSFL. Diagnoses were self-reported, the data were collected at a single point in time, and the reason for the difference between areas remains unclear. The authors said future work should rely on objective medical records and long-term monitoring to test the results. The study was published in the journal Risk Analysis.
