Mortality from lung cancer in an acetylene and phthalic anhydride plant: A case-referent study. Scand j work environ health 9 (1983) 455-462. The study tested the hypothesis that an excess of lung cancer observed in a small town of the Milano Province in Italy was attributable to occupational exposures in a chemical plant (SISAS) producing mainly acetylene, phthalic anhydride, and their derivatives. Exposures included a large number of chemicals, some of which are known or suspected carcinogens such as soot and phthalates. The local register of deaths was the source of the cases and referents. The cases (N = 43) were the male residents in the town who had died from lung cancer from 1976 to 1979. The referents were a sample of residents from the same town who had died during the same four-year period from causes other than respiratory cancer. Causes of death were validated through clinical data and relatives' reports. Information for a complete occupational history and on smoking habits was collected in interviews of the next of kin of each study subject. After control for age and smoking, the risk of dying from lung cancer for the subjects previously employed at the SISAS plant relative to those never occupationally exposed was 5.6 (95% confidence limits 1.9-16.2). The risk for exposure to lung carcinogens in work environments other than SISAS was 1.7 (95% confidence limits 0.9-3.5). On the whole, occupational exposure to chemical carcinogens accounted for about one-third of the total number of lung cancer deaths that occurred in the area during the study period. The results call for further investigation of specific chemicals, mainly soot and phthalates, in the etiology of lung cancer.