Chromosome changes in lymphocytes after occupational exposure to toluene.

Cytogenetic analyses were carried out in peripheral lymphocytes from 20 male workers exposed only to toluene in a rotogravure plant for more than 16 years. As compared with a group of 24 unexposed controls, significantly higher yields of chromatid breaks, chromatid exchanges and gaps were observed. The number of SCEs was significantly increased in smoking and non-smoking toluene-exposed workers compared with the corresponding control groups.