Chromosome damage in asbestos-exposed workers, measured by sister chromatid exchange

Abstract

Objective: To determine the relationship between asbestos exposure and chromosome damage, as depicted by sister chromatid exchange frequency.

Design: Descriptive, cross-sectional study.

Setting: Asbestos-products factory

Subjects: 31 asbestos-exposed subjects and 21 unexposed subjects Main outcome measure: Mean sister chromatid exchange (SCE) frequency per metaphase cell.

Results: The control group had a slightly higher mean SCE frequency per cell than the exposed group (3.4%) but this difference was not statistically significant (p = 0.5935). Smoking contributed significantly to SCE frequencies in both the exposed and unexposed groups. The mean SCE frequencies per cell in the exposed group were 10.49 for smokers and 8.59 for non-smokers (p = 0.0078). The frequencies for smokers and non-smokers in the unexposed group were 10.83 and 8.58, respectively (p = 0.0257).

Conclusions: The failure to observe an increase in SCE frequency does not rule out asbestos exposure as a genotoxic agent. Rather, it may help to resolve the limitations of this method for detecting genetic damage. Alternatively, the fibre levels to which this group was exposed may have been too low to cause chromosome damage.