Occupational risk factors and liver cancer. A retrospective case-control study of primary liver cancer in New Jersey.

A retrospective case-control study was conducted to identify occupational risk factors associated with primary liver cancer in New Jersey, with particular focus on agricultural occupations and pesticide exposures. Hospital record room, tumor registry, and death certificate searches for the diagnosis of primary liver cancer resulted in identification of 959 cases of which 335 were subsequently confirmed. Interviews were completed for 265 persons with liver cancer diagnosed between January 1, 1975 and March 1, 1980 and for 530 matched controls; 96% of all interviews were conducted with family members of deceased or incompetent study subjects. Analyses of employment in agricultural occupations identified male farm laborers as having an odds ratio of 1.89 (95% confidence interval (CI) 1.19-3.00). An estimated relative risk of 3.20 (CI 1.11-9.21) was found for males engaged in winemaking. Among nonagricultural occupations, elevated risks were found for males working as bartenders and those employed in eating and drinking places, laundries and dry cleaning services, and gasoline service stations. An elevated risk of liver cancer was also associated with females employed as cleaning service workers. Hepatitis and cirrhosis could not be evaluated as risk factors in this study. Dose-response trends by level of alcohol consumption were found for both males and females.