OCCUPATIONAL CHRONIC EXPOSURE TO ORGANIC-SOLVENTS .8. PHENOLIC COMPOUNDS-METABOLITES OF ALKYLBENZENES IN MAN - SIMULTANEOUS EXPOSURE TO ETHYLBENZENE AND XYLENES

Four female assistants using a mixture of xylenes and ethylbenzeneas solvent in a histology laboratory were examined according to the concentrations of solvents in blood and the excretion of phenolic compounds in urine during 24 h. The average concentrations of (m+p)-xylene and ethylbenzene in air were between 56 and 68 ppm and 34 and 41 ppm respectively. It is shown that about 1.1-1.4% of the retained ethylbenzene is metabolized to 2-ethyl-phenol. 2,4-Dimethylphenol as a metabolite of m-xylene could not be detected. It is supposed that a competitive reaction mechanism between xylenes and ethylbenzene takes place preventing m-xylene from oxidation at the aromatic nucleus. Possible carcinogenic properties of epoxides formed as intermediates must be considered.-The estimation of threshold values for the concentration of solvents in blood was attempted. © 1979 Springer-Verlag.