DNA SINGLE-STRAND BREAKAGE, DNA-ADDUCTS, AND SISTER-CHROMATID EXCHANGE IN LYMPHOCYTES AND PHENANTHRENE AND PYRENE METABOLITES IN URINE OF COKE-OVEN WORKERS

Objectives-To investigate the specificity of biological monitoring var iables (excretion of phenanthrene and pyrene metabolites in urine) and the usefulness of some biomarkers of effect (alkaline filter elution, P-32 postlabelling assay, measurement of sister chromatid exchange) i n workers exposed to polycyclic aromatic hydrocarbons (PAHs). Methods- 29 coke oven workers and a standardised control group were investigate d for frequencies of DNA single strand breakage, DNA protein cross lin ks (alkaline filter elution assay), sister chromatid exchange, and DNA adducts (P-32 postlabelling assay) in lymphocytes. Phenanthrene and p yrene metabolites were measured in 24 hour urine samples. 19 different PAHs (including benzo(a)pyrene, pyrene, and phenanthrene) were measur ed at the workplace by personal air monitoring. The GSTT1 activity in erythrocytes and lymphocyte subpopulations in blood was also measured. Results-Concentrations of phenanthrene, pyrene, and benzo(a)pyrene in air correlated well with the concentration of total PAHs in air; they could be used for comparisons of different workplaces if the emission compositions were known. The measurement of phenanthrene metabolites in urine proved to be a better biological monitoring variable than the measurement of l-hydroxypyrene. Significantly more DNA strand breaks in lymphocytes of coke oven workers were found (alkaline filter elutio n assay); the DNA adduct rate was not significantly increased in worke rs, but correlated with exposure to PAHs in a semiquantitative manner. The number of sister chromatid exchanges was lower in coke oven worke rs but this was not significant; thus counting sister chromatid exchan ges was not a good variable for biomonitoring of coke oven workers. Al so, indications for immunotoxic influences (changes in lymphocyte subp opulations) were found. Conclusions-The measurement of phenanthrene me tabolites in urine seems to be a better biological monitoring variable for exposure to PAHs than measurement of hydroxypyrene. The alkaline filter elution assay proved to be the most sensitive biomarker for gen otoxic damage, whereas the postlabelling assay was the only one with s ome specificity for DNA alterations caused by known compounds.