POLYCYCLIC AROMATIC HYDROCARBON-DNA ADDUCTS IN WHITE BLOOD-CELL DNA AND 1-HYDROXYPYRENE IN THE URINE FROM ALUMINUM WORKERS - RELATION WITH JOB CATEGORY AND SYNERGISTIC EFFECT OF SMOKING

We examined a group of 105 workers from a primary aluminum plant for t he presence of polycyclic aromatic hydrocarbon (PAH)-DNA adducts in th eir WBC and 1-hydroxypyrene in their urine. Workers were recruited fro m five job categories with different PAH exposure: the anode factory; the bake oven; and the electrolysis and the pot-relining departments. Unexposed workers from the foundry department served as the control gr oup. The exposure to PAH was measured by personal monitoring, and the average PAH concentrations in the work atmosphere ranged from 0.4 mug/ m3 in the foundry to 150 mug/m3 in the pot-relining department. The av erage exposure to benzo(a)pyrene was under the Swedish exposure limit of 5 mug/m3. The internal dose of pyrene was measured utilizing the 1- hydroxpyrene concentration in pre- and postshift urine samples. High e xposure to PAH in the work atmosphere was associated with increased co ncentrations of 1-hydroxypyrene in the urine. The average increase in concentration of 1-hydroxypyrene ranged from 0.2 mumol/mol creatinine in the control group to 5.9 mumol/mol creatinine in the pot-relining d epartment; an accumulation of 1-hydroxyprene over a 5-day working peri od was observed. A good correlation was found between PAH exposure and the concentration of 1-hydroxypyrene in the urine on a group level (r (s) = 0.90; P = 0.02). PAH-DNA adducts were determined by P-32-postlab eling analysis (nuclease P1 enrichment procedure). In 93% of the worke rs, PAH-DNA adducts were detected and workers with a high PAH exposure had significantly higher PAH-DNA adduct values than did those with a low PAH exposure. A good correlation was found between PAH exposure an d the average PAH-DNA adduct values in blood on a group level (r(s) = 0.90; P = 0.02), but not on the level of individual workers. A highly significant correlation was found between the average PAH-DNA adduct v alues and the concentration of 1-hydroxypyrene in the urine at the end of day 5 for smokers (r(s) = 0.66; P < 0.001; n = 23), but for nonsmo kers this relationship was only marginally significant (r(s) = 0.25; P = 0.089; n = 31). Multiple regression analysis clearly showed the eff ect of smoking on DNA adduct values in WBCs (P = 0.10), as well as on 1-hydroxypyrene concentration in the urine (P < 0.001). Higher DNA add uct values in smokers were found only in those job groups with high PA H exposure. Higher concentrations of 1-hydroxypyrene in smokers were f ound in all groups, but the difference between smokers and nonsmokers was most pronounced in those groups with the highest PAH exposure. The strong effect of smoking in the exposed groups suggests a synergistic effect of smoking in combination with occupational PAH exposure on th e formation of PAH-DNA adducts and 1-hydroxypyrene in the urine.