Lung cancer and air pollution in southcentral Los Angeles County.

An increased rate of lung cancer has been consistently observed from 1968-1972 among males in southcentral Los Angeles. This excess risk occurs across several social classes and occupational categories. No differential excess of oral cavity, pancreatic, laryngeal and bladder cancer was observed in the same area, lessening the possibility that regional variations in smoking habits accounted for the excess lung cancer. Air sampling has indicated an excess of certain polynuclear aromatic hydrocarbons (PAH) in southcentral Los Angeles. There was a correlation between the geographic distribution of lung cancer cases and the general location of industries which have emitted these PAH. A case-controlled study of smoking, occupational and residential history in the southcentral area is underway.