Air pollution as a risk factor in lung cancer

Retrospective data on residential and employment history and on smoking were obtained from 417 white male lung cancer patients and 752 controls with nonrespiratory, nonneoplastic diseases, from Erie County, New York, admitted to Roswell Park Memorial Institute from 1957-1965. Total suspended particulate data and a historical review of problem point sources of pollution were used to delineate air pollution zones. The findings did not support the hypothesis that air pollution alone significantly increased risk for lung cancer. However, there was increased risk from smoking and occupational exposures if there was also long-term exposure to air pollution. The risk for heavy smokers with heavy exposure to air pollution was over four times that of men with none of the high exposure traits. The findings suggest an apparent synergistic mechanism involving smoking and air pollution and smoking and occupational exposures. The findings are consistent with previous epidemiologic studies and with biologic and experimental evidence. The limitations of the methods used here necessitate further study and replication. However, the study indicates that air pollution should not be dismissed as a risk factor in lung cancer.