A new indirect method for detection of metabolites of polycyclic aromatic compounds in urine

A frequently used means of assessing exposure to PAHs is measurement of uri nary 1-hydroxypyrene and its metabolites following enzymatic deconjugation. Singh et al.([1]) have reported an HPLC method which eliminates the deconj ugation step, and directly measures levels of metabolites as well as free 1 -hydroxypyrene. Using the samples from their study, including urine from mi ce fed coal tar, and urine from workers occupationally exposed to coal tar, we have developed a rapid, sensitive method for determining exposures to P AHs. The method takes advantage of the extreme mutagenicity of nitro-PAH in the Ames Assay. Urine samples were chemically nitrated and tested in Ames strain TA98. For the mouse urines, correlation of mutagenic potency with va rious measures of coal tar intake and excretion gave R-2 values greater tha n 0.97. There was more scatter in the worker study, possibly reflecting dif ferential responses of the two methods to non-coal tar PAH exposures.