Risk Assessment of Lung Cancer Caused by Indoor Radon Exposure in China during 2006-2016: A Multicity, Longitudinal Analysis

Indoor radon is a well-documented environmental factor as a second cause of lung cancer. Based on the chronological data on indoor radon concentration, lung cancer incidence, and the distribution of sex-age-specific population, the risk of lung cancer caused by indoor radon exposure in a total of 15 cities in China was assessed by using the risk model developed by the U.S. Environmental Protection Agency (EPA) in this study. The estimate revealed that both the excess relative risk (ERR) and lifetime relative risk (LRR) have obviously increased after 2010. The population attributable risk (PAR) in 2016 was estimated in a range from 6.66% to 22.42%, with a median of 15.33% for the 15 cities. The lung cancer incidence attributed to indoor radon in 2016 ranged from 3.96 to 15.07 per 10,000 population in males and 1.21 to 8.27 per 10,000 population in females. Across age and sex, the risk of lung cancer caused by indoor radon was found more pronounced in males and 40-45 age groups. The chronological variation of radon concentrations was considered in this study; the estimate of lung cancer caused by indoor radon in China is considered more reasonable than ever before.