Multi-exposure environmental mapping and scale effects in lung cancer risk assessment: An ecological synthesis from central Argentina.

e22582 Background: Lung cancer is a major public health burden and, beyond tobacco smoking, its risk may be influenced by modifiable environmental exposures. Residential radon and arsenic in drinking water are Group 1 carcinogens (WHO/IARC) associated with increased lung cancer risk. In Córdoba Province, central Argentina, published studies at different spatial scales allow joint examination of these exposures and the spatial distribution of lung cancer. We integrated this evidence to inform prevention priorities and to discuss limitations due to spatial scale mismatch. Methods: We conducted a broad spatial integration of published data on residential radon, groundwater arsenic content and lung cancer, considering ecological inference and the modifiable areal unit problem. Results: Residential radon measured in the western and northwestern Córdoba Pampean Ranges (dominated by metamorphic and granitic rocks) showed strong micro-scale variability (6–307 Bq/m³; mean ~46); and about 6% exceeded the WHO reference level (100 Bq/m³). Concentrations were lower in warmer months and higher in below-ground rooms, with exceedances concentrated in granitic settings and areas affected by active fault systems. Groundwater arsenic showed a macro-regional pattern across the province, with the highest concentrations in the southern and southeastern lowland plains and generally lower levels in the western and northwestern mountains. Registry-based analyses identified 8,246 lung cancer cases diagnosed during 2004–2014 (ages 35–84) and significant department-level spatial clustering, with hotspots in the eastern and southeastern departments and lower case concentration in the northwest. The arsenic regional gradient qualitatively resembled the cancer hotspot pattern. Radon information still remained highly localized, thus an ecological epidemiological approach cannot be applied in the identified high-radon areas. Conclusions: This ecological integration of published evidence suggests qualitative spatial concordance between elevated groundwater arsenic and higher lung cancer burden in eastern and southeastern Córdoba. Residential radon shows strong local and seasonal variability, limiting comparison with large-area disease maps without standardized long-term measurements. Strengthening exposure monitoring can improve population-level risk assessment and guide prevention planning.