Study of the genotoxicity of toluene.

Chromosome analysis was conducted for peripheral lymphocytes of 23 printers exposed to toluene concentrations of 590 mg/m3 in a rotary machine workshop and to rotogravure printing inks. The percentages of aberrant cells were 2.30 in the printers and 1.46 in the control group (n = 22) (p < .05). The concentration of hippuric acid in printers was significantly higher than in the control group (p < .01), and the level of blood toluene at the end of the workshift was 0.500 mg/l. The authors also examined rotogravure printing inks-considered a potential source of genotoxic polycyclic aromatic hydrocarbons because they contained carbon black-their use in printing plants, and previous documentation of increased chromosomal aberrations in rotogravure printers. Only milligrams of fluorene and phenanthrene per gram of the printing inks were found; no polycyclic aromatic hydrocarbons with carcinogenic properties were discovered in the inks. The authors used Salmonella typhimurium indicator strains TA 98, TA 100, TA 1537, and YG 1041 in spot tests and indicator strains TA 98 and TA 100 in plate-incorporation assays to determine that there was no bacterial mutagenicity of all four colors of rotogravure inks. Urinary mutagenicity, which was evaluated with a microsuspension assay containing YG 1041 indicator strain both in the presence and absence of metabolic activation, was also studied. No significant difference in bacterial mutagenicity was found between the exposed and control groups. The increased percentage of aberrant cells in printers can be explained by exposure to genotoxicants that are not excreted in urine. Toluene was the most likely cause of the aberration.