Increased frequency of lymphocyte micronuclei in workers producing reinforced polyester resin with low exposure to styrene.

A new micronucleus method based on the analysis of lymphocytes with preserved cytoplasm revealed an increased frequency of micronuclei in 38 workers employed in a plant producing styrene-modified polyester resin as compared to the frequency in 20 referents (5.9 vs 3.6%). The time-weighted average of the styrene concentration in the workroom air varied between 1 and 36 ppm (mean 13 ppm) during the last year and correlated well to low urinary levels of mandelic acid, which ranged from 9 to 316 mg/g of creatinine (mean 65 mg/g of creatinine).