CYTOGENETIC STUDIES IN LYMPHOCYTES OF WORKERS EXPOSED TO 2,3,7,8-TCDD

Chromosome aberrations and sister chromatid exchanges (SCEs) were eval uated in 27 workers with current 2,3,7,8-tetrachlorodibenzo-p-dixoin ( TCDD) blood lipid concentrations exceeding 40 parts per trillion (ppt) and in 28 unexposed referents of similar age. No statistical differen ces were found between the two groups in the percentages of gaps, chro matid or chromosome exchanges, chromatid or chromosome breaks/fragment s/deletions, multiple aberrations, or the overall percentage of aberra tions including gaps (1.33% in the exposed group vs 1.75% in the refer ent group) or excluding gaps (0.54% in each group). There was an incre ased rate of SCEs per cell (P=0.051) and a higher percentage of cells with more than 10 SCEs (P=0.064) in the exposed group; however, these associations were no longer significant when smoking status was includ ed as covariate. Additionally, neither current nor back-calculated TCD D concentration was a significant predictor of these parameters based on multiple linear and rank regression analyses.