Increase in antipyrine clearance in workers exposed to phenol and toluene in the petrochemical industry.

In 90 workers of the petrochemical industry occupationally exposed to a mixture of petroleum derivatives, including 60 persons exposed mainly to phenol and 30 to toluene, the metabolic activity of the liver was examined using the antipyrine test. In both groups of subjects, an increase of antipyrine clearance in saliva was observed. Occupational exposure to lipophylic derivatives of petroleum seems to induce the function of liver microsomal enzymes.