Chromosome Studies in Workers Exposed to Benzene or Toluene or Both

Abstract

Chromosome studies were carried out on peripheral blood lymphocytes of 34 workers of a rotogravure plant, and in 34 controls matched for sex and age. Ten of the workers were exposed to benzene before 1953 and then to toluene, and 24 have been exposed only to toluene after 1953. The proportions of unstable and stable chromosome aberrations were significantly higher statistically in the benzene group compared with the controls, and in the benzene group in comparison with the toluene group. No significant differences were found between the frequencies of chromosome changes in the toluene and control groups.