Development of methodologies to evaluate certain classes of polycyclic aromatic compounds (PAC) detected in complex mixtures to which humans are exposed would greatly improve the diagnostic potential of (32)P-postlabeling analysis. Identification of DNA adduct patterns of specific exposure-related marker adducts would strengthen associations between observed DNA adducts and exposures to different environmental pollutants (e.g., kerosene, cigarette smoke, coke oven, and diesel). Diesel-modified DNA adduct patterns were compared in various in vitro and in vivo rodent model systems and then compared to DNA reactive oxidative and reductive metabolites of 1-nitropyrene. The formation of nitrated-polycyclic aromatic hydrocarbon (nitrated-PAH) DNA adducts, derived from the metabolism of diesel extract constituents, was enhanced relative to other PAH-derived DNA adducts via xanthine oxidase-catalyzed nitroreduction. These adducts were detectable only by the butanol extraction version of the postlabeling analysis. Marker adducts detected in the various test systems presented here will assist in characterizing nuclease-P1-sensitive nitrated PAH adducts in humans.