Lymphocyte micronuclei and sister chromatid exchanges among Canadian federal laboratory employees

Blood lymphocytes from 59 federally employed Canadian laboratory workers, 137 nearby office employees, and 11 workers with a mixed employment history were examined for the presence of sister-chromatid exchanges and micronuclei. These laboratory workers were exposed routinely to a host of organic solvents and had previously voiced complaints regarding the adequacy of the ventilation system in their building. Overall, no relationship between laboratory work and either cytogenetic endpoint was observed. The two tests were only weakly correlated, but in a multivariate analysis, both were associated with recent and past smoking. Within-person variation was measured for the sister-chromatid exchange assay, and it and other possible sources of variation are discussed.