title: Bioaccumulation of benzo(a)pyrene from sediment by fathead minnows: effects of organic content, resuspension and metabolism.
abstract: The accumulation of 14C-benzo(a)pyrene (BaP) sorbed to sediment was examined in fathead minnows (Pimephales promelas) to compare uptake from sediment with a high organic carbon (OC) content (7.7%), to that with a low OC content (2%). Ingestion of sediments was quantified by co-labeling the sediment with 141Cerium, which was not assimilated by the fish. Results of this study indicated that (1) significantly greater quantities of BaP were dissolved in water over low-OC sediment, compared to water over high-OC sediment, (2) fish disturbed the sediment and increased the concentration of BaP in centrifuged (particle-free) water, (3) fish ingested significantly more of the low-OC sediment than high-OC sediment, perhaps in response to the lower food quality of the low-OC sediment, and (4) uptake of BaP from sediment ingestion contributed <3% of the total flux of BaP into the fish. Primarily as a result of the greater concentration of BaP in water, fish from the low-OC exposures had significantly higher rates of BaP accumulation. However, after 48 h the body burdens in these fish declined by 50%, likely due to the induction of MFO enzymes in response to accumulation of BaP. A smaller effect was apparent in the fish from the high-OC exposures, consistent with the lower dose of BaP they experienced. These results illustrate the complex, and sometime counterintuitive, interactions that affect the uptake and bioaccumulation of sediment-associated contaminants.
authors.affiliation: Department of Geological Sciences, University of Tennessee, 306 Geology Building, Knoxville, Tennessee 37996-1410, USA. jmccart1@utk.edu
authors.forename: J F
authors.initials: JF
authors.lastname: McCarthy
authors.forename: L W
authors.initials: LW
authors.lastname: Burrus
authors.forename: V R
authors.initials: VR
authors.lastname: Tolbert
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000378:metabolism / Q000633:toxicity*; D001822:Body Burden; D002273:Carcinogens / Q000378:metabolism / Q000633:toxicity*; D003530:Cyprinidae / Q000502:physiology*; D019015:Geologic Sediments / Q000737:chemistry; D006899:Mixed Function Oxygenases / Q000494:pharmacology; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D002273:Carcinogens; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene; D006899:Mixed Function Oxygenases