Carcinogenic chemicals in the occupational environment.

A survey of occupational carcinogens by the Institute of Occupational Health, Finland shows that more than 100,000 workers are exposed to carcinogenic substances. The most common exposures are silica, wood dust, tobacco smoke and lead compounds. Based on biological monitoring of workers over the years it appears that overall lead exposure has decreased but exposure to styrene, trichloroethylene and tetrachloroethylene has decreased only slightly or remained constant. The biological monitoring data are based on samples sent by the workplaces on their initiative presenting no scientifically selected sampling. Thus due caution is needed in the interpretation of the trends.