DNA adducts as a biomarker of polycyclic aromatic hydrocarbon exposure in aquatic organisms: relationship to carcinogenicity

The use of DNA adduct measurement as a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs) is now well established in ecotoxicology. In p articular, DNA adduct levels in aquatic organisms has been found to produce a better correlation with PAH exposure than PAH concentrations in organism s. DNA adducts levels are most commonly determined using the P-32-postlabel ling assay which measures total aromatic adducts. The relationship between relative DNA adduct formation and carcinogenicity has been investigated for a number of carcinogenic and non-carcinogenic PAHs using an in vitro syste m. Our results demonstrate that relatively high levels of DNA adducts can b e produced by some non-carcinogenic PAHs, while other non-carcinogenic comp ounds do not produce detectable adducts. In addition, it has been shown tha t all carcinogenic PAHs investigated produce DNAadducts and that a relation ship exists between relative adduct formation and carcinogenic potency. An investigation of adduct levels in fish liver and crustacean hepatopancreas in Oxley Ck, Brisbane has shown that higher than expected DNA adduct levels were correlated with the presence of carcinogenic and noncarcinogenic PAHs with high relative adduct forming potential.