PREVENTION OF CIGARETTE SMOKE INDUCED LUNG CANCER BY LOW LET IONIZING RADIATION

Abstract

Lung cancer is the most prevalent global cancer, similar to 90% of which is caused by cigarette smoking. The LNT hypothesis has been inappropriately applied to estimate lung cancer risk due to ionizing radiation. A threshold of similar to 1 Gy for lung cancer has been observed in never smokers. Lung cancer risk among nuclear workers, radiologists and diagnostically exposed patients was typically reduced by similar to 40% following exposure to < 100 mSv low LET radiation. The consistency and magnitude of reduced lung cancer in nuclear workers and occurrence of reduced lung cancer in exposed non-worker populations could not be explained by the HWE. Ecologic studies of indoor radon showed highly significant reductions in lung cancer risk. A similar reduction in lung cancer was seen in a recent well designed case-control Study of indoor radon, indicating that exposure to radon at the EPA action level is associated with a decrease of similar to 60% in lung cancer. A cumulative whole-body dose of similar to 1 Gy gamma rays is associated with a marked decrease in smoking-induced lung cancer in plutonium workers. Low dose, low LET radiation appears to increase apoptosis mediated removal of a-particle and cigarette smoke transformed pulmonary cells before they can develop into lung cancer.