Abstract
BACKGROUND: As nuclear energy expands globally as a low-carbon power source, ongoing public health surveillance remains important for populations residing near nuclear facilities. Although ionizing radiation is an established carcinogen, population-level patterns of cancer incidence near nuclear installations have shown heterogeneity across tumor types and regional settings. METHODS: This nationwide, cross-sectional study used Korea's National Health Information Database (2005-2022), comprising over 103 million person-years of observation from residents living within 30 km of four nuclear power plants and within 10 km of one research reactor. Age-standardized incidence ratios (SIRs) were calculated for 61 tumor types by sex, distance, and facility type using national reference rates. Regional socioeconomic characteristics (education level, occupation, and household income) from the Korea Community Health Survey and proximity to industrial complexes derived from spatial mapping data were examined descriptively to characterize contextual differences across study areas. RESULTS: Cancer incidence patterns varied by facility and tumor type. Elevated SIRs were observed for brain and central nervous system (CNS) tumors (1.41-2.46) and bladder cancer (1.25-1.51) near certain nuclear power plants, and for thyroid (1.07-1.32), breast (1.11-1.21), and CNS tumors (1.56-3.37) near the research reactor. No consistent gradient by residential proximity was observed across sites. Descriptive assessments indicated regional variation in socioeconomic profiles and industrial proximity, with higher educational attainment and household income observed in areas surrounding the research reactor and certain industrialized nuclear power plant regions. CONCLUSION: This study provides a comprehensive description of cancer incidence patterns among populations living near nuclear facilities in Korea. The findings underscore the importance of careful contextual interpretation when evaluating spatial variation in cancer incidence and support the role of population-based monitoring frameworks, as well as the need for continued refinement of exposure characterization, to inform public health planning.