CANCER INCIDENCE AMONG FINNISH WORKERS EXPOSED TO AROMATIC-HYDROCARBONS

Objectives: To assess whether occupational exposure to aromatic hydroc arbons increases carcinogenic risk. Methods: We followed cancer incide nce among 3,922 male and 1,379 female workers monitored for exposure t o styrene, toluene, or xylene. The follow-up after the first personal measurement comprised 66,500 person-years at risk over the period 1973 -1992. We computed the indirectly standardized incidence ratios (SIR) with 95% confidence interval (CI) with regard to age-, gender-, and pe riod-specific incidence rates of cancer in the Finnish general populat ion. Results: The overall rate of cancer incidence for the total cohor t was fairly similar to that of the general population. The risk for n ervous system tumors was increased at 10 years after the first persona l measurement (SIR 2.80, CI 1.03-6.08). For styrene there was an exces s risk for rectal cancer (SIR 3.11, CI 1.14-6.77), and risks for pancr eatic and nervous system tumors were increased nonsignificantly. For t oluene and xylene, no clear increase in cancer risk was found. Conclus ions. The data are not supportive of an overall increase in the cancer risk for these solvents, even though we cannot rule out site-specific associations with the rectum, pancreas, and nervous system. There is supporting evidence in the epidemiology literature for pancreatic canc er risk and heavy exposure to styrene. More studies are warranted on s olvents, with detailed information on lifetime exposures and habits be ing collected whenever possible.