Cancer Incidence and Childhood Residence Near the Coldwater Creek Radioactive Waste Site

Importance Beginning in the 1940s, radioactive waste from the effort to develop an atomic bomb was stored in the open near the St Louis, Missouri, airport, and over several decades contaminated nearby Coldwater Creek. Objective To evaluate whether living near Coldwater Creek in childhood was associated with self-reported cancer incidence in the St Louis Baby Tooth-Later Life Health Study (SLBT). Design, Setting, and Participants The SLBT cohort study was centered in St Louis and included individuals who donated their baby teeth from 1958 to 1970 to assess exposure to atmospheric nuclear weapons testing. Participants for the present analysis were recruited from June 22, 2021, to September 18, 2024. Exposures Residential proximity to Coldwater Creek (<= 1, >1 to 5, >5 to 20, and >20 km) in childhood when participants donated their baby teeth. Main Outcomes and Measures Self-reported cancers, from which several composite outcomes were constructed: any cancer, solid cancers (all except leukemias and lymphomas), known radiosensitive cancers (thyroid, breast, leukemia, and basal cell), and nonradiosensitive cancers (all except thyroid, breast, leukemia, and basal cell). Odds ratios (OR) and 95% CIs between living near Coldwater Creek and several self-reported cancer outcomes were estimated, adjusting for sociodemographic characteristics and neighborhood median income. Results There were 4209 eligible SLBT participants, of whom 2369 (56.3%) were female. The mean age at enrollment was 63 (range, 55-77) years. The background risk of any form of cancer was 24%. The OR was 1.44 (95% CI, 0.96-2.14) for any form of cancer comparing participants living 1 km or nearer with those living further than 20 km. There was a significant association for radiosensitive cancers (OR, 1.85; 95% CI, 1.21-2.81) but not for nonradiosensitive cancers (OR, 1.41; 95% CI, 0.86-2.30) for participants living 1 km or nearer vs further than 20 km. There was evidence of a dose-response association, where cancer risks were still elevated (albeit smaller) for those living in buffers of greater than 1 to 5 km and greater than 5 to 20 km. Despite imprecision in some of the site-specific estimates, clear signals for some organs, such as the thyroid, were still detected (OR for living <= 1 vs >20 km, 5.00; 95% CI, 1.23-20.32). Conclusions and Relevance In this cohort study of baby teeth donors from the Greater St Louis area, evidence suggested a positive association between living near Coldwater Creek in childhood and risk of cancer.