Relationship Between Inhaled PAH and Urinary Excretion of Phenanthrene, Pyrene and Benzo[a]pyrene Metabolites in Coke Plant Workers

By means of personal air samplers the exposure to polycyclic aromatic hydrocarbons (PAH) of four coke employees working at different locations was measured during 4 running days. Simultaneously the 24 hrs urines were collected. A simple, well reproducible method for the determination of 9,10-dihydroxy-9,10-dihydrobenzo[a]pyrene, 1-; 2-; 3-; 4- and 9-hydroxyphenanthrenes, 1,2-; 3,4-; and 9,10-dihydroxydihydrophenanthrenes as well as 1-hydroxypyrene and 1,2-dihydroxy-1,2-dihydropyrene was used. As expected, workers on the battery topside are most exposed and, accordingly, excrete by far the highest amount of PAH metabolites. A good correlation between the PAH inhaled during 8 hrs and the metabolites excreted in the 24 hrs urine is observed. 20% to 30% of the inhaled phenanthrene is excreted as dihydrodiols, but only 0.5% of the inhaled benzo[a]pyrene forms 9,10-dihydrodiol in the urine. The individual invariance of the metabolite profile of the isomeric phenols and dihydrodiols indicates a genetically caused enzyme pattern of oxygenases, which can or cannot be induced by exogenous factors. More investigations are necessary to clarify whether this metabolic profile may be suitable as a marker for carcinogenic risk.