Chromosome changes in workers (smokers and nonsmokers) exposed to automobile fuels and exhaust gases.

Abstract
The incidence of chromosome changes in men occupationally exposed to automobile fuels and exhaust genes was investigated. Blood samples were taken from the following 4 groups of 12 men: drivers of diesel-engine trucks, drivers of gasoline-engine trucks, automobile inspectors and a reference group. The mean in the groups were matched with respect to age, smoking habits and length of time in their respective jobs. Chromosome preparations from lymphocytes were made and analyzed by standardized routine methods, and the frequencies of gaps, breaks and sister chromatid exchanges were recorded. Statistical analysis of the results gave no evidence for a marked occupational effect, although there remains a grave suspicion that working with diesel motors may cause an increased level of chromosomal changes. Smokers showed a significant or near significant increase in breaks, total aberrations and sister chromatid exchanges over the nonsmokers in 3 of the groups. An analysis of the data revealed a weak positive correlation between the frequencies of chromosome breaks and sister chromatid exchanges in an individual.