Residential radon and COPD. An ecological study in Galicia, Spain

Abstract

Objetive: Radon is a human lung carcinogen but it might be linked with other respiratory diseases. We aimed to assess the relationship between residential radon exposure and COPD (Chronic Obstructive Pulmonary Disease) prevalence and hospital admissions at a municipal level. Methods: We designed an ecological study where we included those municipalities with at least 3 radon measurements. Using mixed Poisson regression models we calculated the relative risk (RR) for COPD for each 100 Bq/m 3 of increase in radon concentration and the relative risk for COPD using a cutpoint of 50 Bq/m 3 . We performed separate analyses for sex and municipalities with > 5 radon measurements. Results: 3,040 radon measurements in 237 municipalities (75.2% of total) and 49,393 COPD cases (67.6% males) were included. Median residential radon concentration was 107 Bq/m 3 (range:13-569 Bq/m 3 ). 30.8% of municipalities had radon levels above 148 Bq/m 3 and 13.9% above 200 Bq/m 3 . Relative risk for COPD prevalence was 0.95 (95%CI 0.92-0.97) for each 100 Bq/m 3 . For hospital admissions, RR was 1.04 (95%CI 1.00-1.10). Relative risks were higher for women compared to men. Relative risk for hospital admissions was 1.17 (95%CI 0.99-1.40) for women living in municipalities with > 50 Bq/m3 compared with those with lower concentrations. Conclusions: Residential radon exposure may increase the risk of COPD and hospital admissions for this disease. Women have a higher risk than men. These results highlight the importance of residential radon as a public health concern, since it suggests that it might affect respiratory diseases other than lung cancer. It is necessary to implement preventive measures to protect population from this indoor carcinogen.