Lifetime lung cancer risk due to radiation exposure considering smoking history for Japanese people

Shimada, Kazumasa ; Kai, Michiaki*

This paper describes lung cancer mortality risks due to radiation exposure considering the history of smoking in Japanese people. In this study, we calculated the DALY of lung cancer mortality for Japanese males considering the joint effects of radiation and smoking using the generalized multiplicative excess relative risk interaction model (GM model). First, we estimated the lung cancer baseline risk for non-smokers to divide the risk of smoking for mixed population groups that include smokers and non-smokers. Second, we developed a radiation risk model from single to chronic exposure to be able to evaluate the risk of cancer in existing and control exposure situations. Forth, the maximum relative risks of lung cancer mortality for smokers and non-smokers induced by a radiation exposure of 20 mGy/y for Japanese smokers between the age of 20 and 60 years were calculated using the GM model to be 22.2 for men and 15.7 for women, respectively. Therefore, our calculations show that only considering radiation risks strongly underestimate the real risk of lung cancer when the smoking history is not taken into account. Our study indicates that estimations of the health risk due to radiation exposure should consider not only age and gender but also the history of smoking for deriving an occupational exposure limit.