Inverse-distance-weighted residential proximity to nuclear power plants and cancer incidence in South Korea: A nationwide ecological study.

Residential proximity to nuclear power plants has been a continuing public health concern, yet epidemiological evidence remains inconsistent. This ecological study evaluated the association between residential proximity to nuclear power plants and cancer incidence across 123 administrative districts in South Korea from 1999 to 2018. Proximity was estimated using an inverse-distance-weighted index incorporating contributions from multiple operating reactor units, with moving-averages applied to account for latency. Gaussian generalized estimating equation regression models with an identity link were fitted using log-transformed district-level age-standardized incidence rates as the outcome, adjusting for environmental, socioeconomic, and demographic covariates. Nuclear power plant proximity was positively associated with total cancer incidence in both males and females. In males, associations with total cancer and liver cancer were observed across all moving-average windows, and lung cancer showed positive associations except in the 25-year window. In females, total cancer, colorectal cancer, and thyroid cancer showed positive associations across all moving-average windows. These findings provide a basis for further population-based research to clarify the long-term association between residential proximity to nuclear power plants and cancer incidence.