Living near Coldwater Creek in St. Louis, Missouri, during childhood was found to be associated with an increased risk of overall cancer, according to the findings of a study published in JAMA Network Open.
“Our research indicates that the communities around North St. Louis appear to have had excess cancer from exposure to the contaminated Coldwater Creek,” said corresponding author Marc G. Weisskopf, PhD, ScD, Cecil K. and Philip Drinker Professor of Environmental Epidemiology and Physiology, Department of Environmental Health, Harvard T.H. Chan School of Public Health. “These findings may have broader implications—as countries think about increasing nuclear power and developing more nuclear weapons, the waste from these entities could have huge impacts on people’s health, even at these lower levels of exposure.”
Background
When the first atomic bomb was developed in the United States, uranium was refined in St. Louis, Missouri, and following the Manhattan Project, radioactive waste was stored in a rural area north of St. Louis. Over time, radiologic contaminants leached into Coldwater Creek, which was finally acknowledged in the late 1980s, leading to efforts to remediate the surrounding area. Remediation efforts are estimated to be completed in 2038, according to the U.S. Environmental Protection Agency.
Due to the contaminated Coldwater Creek, communities downstream are expected to have been exposed to ionizing radiation for decades. This has led to concern over excess cancer risk for locals. Prior studies of the increased risks were fraught with errors and did not focus on individuals who lived in the area as children, leading to further study by the Harvard T.H. Chan School of Public Health.
Publication of the study also coincides with the recent passing of an extended version of the Radiation Exposure Compensation Act through Congress, which allows residents to receive compensation for medical bills associated with radiation exposure.
Study Methods
Leung et al conducted a cohort study of 4,209 individuals who lived near Coldwater Creek in their childhood between 1958 and 1972, based off of information collected from the St Louis Baby Tooth–Later Life Health Study (SLBT). The SLBT study included many individuals who had lived near Coldwater Creek as children and had donated their baby teeth, beginning in 1958, for measurements of radiation exposure. The individuals also self-reported their incidences of cancer.
The researchers calculated the distance between the creek and their reported children address at the time of the tooth donation for each participant to assess exposure levels. As such, the study authors acknowledged that they did not have precise radiation contamination exposure estimates.
Key Study Findings
Overall, participants had a background risk of 24% for developing any form of cancer, with 1,009 individuals self reporting having cancer. For those who lived closest to the creek (≤ 1 km) compared with those who lived further away (≥ 20 km), the odds ratio (OR) for developing any form of cancer was 1.44 (95% confidence interval [CI] = 0.96–2.14). Thirty percent of these participants who developed cancer had lived 1 km from Coldwater Creek or less, 28% lived 1 to 5 km away, 25% lived 5 to 20 km away, and 24% lived 20 km away or more.
The risk for developing radiosensitive cancers (ie, thyroid, breast, leukemia, and basal cell cancers) was 1.85 (95% CI = 1.21–2.81) for those who lived closest vs furthest from Coldwater Creek, whereas the risk for developing nonradiosensitive cancers was lower (OR = 1.41; 95% CI = 0.86–2.30). The odds ratio for developing any solid tumor was 1.52.
Site-specific cancer estimates were imprecise, yet signals were still noted for increased odds of affecting certain organs, such as the thyroid (OR = 5.00; 95% CI = 1.23–20.32), when the individuals lived closest to the creek vs further out.
A dose-response association was noted with elevated cancer risks reducing for those living further out from the creek.
Disclosure: The study was funded by the National Institutes of Health. For full disclosures of the study authors, visit jamanetwork.com.
