Chromosome breaks, benzene

In one epidemiological study testing benzene s effects on chromosomal aberrations, benzene appeared to exert a nonrandom effect on chromosomes one, two, four, and nine (Sasiadek et al. 1989). However, this study is limited because relatively few controls were used and all participants (control and exposed) were smokers. The effects of smoking may have confounded the results. In a later paper, extra break points were confirmed on chromosomes 2 and 4, only (Sasiadek and Jagielski 1990). Sister chromatid exchange was not found to be a significant effect of benzene exposure in humans (Seiji et al. 1990 Yardley-Jones et al. 1988) however, poor control selection was used in both studies. Refer to Table 2-5 for a further summary of these results. 

Chromosomal breaks and hyperdiploidy were also observed in human lymphocytes after exposure to hydroquinone in vitro (Eastmond et al. 1994). Benzene metabolites have been shown to form DNA adducts in human bone marrow and HL-60 cells (Bodell et al. 1993 Levay and Bodell 1992). Zhang et al. 

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