title: Tumor prevalence and biomarkers of genotoxicity in brown bullhead (Ameiurus nebulosus) in Chesapeake Bay tributaries.
abstract: We surveyed four Chesapeake Bay tributaries for skin and liver tumors in brown bullhead (Ameiurus nebulosus). We focused on the South River, where the highest skin tumor prevalence (53%) in the Bay watershed had been reported. The objectives were to 1) compare tumor prevalence with nearby rivers (Severn and Rhode) and a more remote river (Choptank); 2) investigate associations between tumor prevalence and polynuclear aromatic hydrocarbons (PAHs) and alkylating agents; and 3) statistically analyze Chesapeake Bay bullhead tumor data from 1992 through 2008. All four South River collections exhibited high skin tumor prevalence (19% to 58%), whereas skin tumor prevalence was 2%, 10%, and 52% in the three Severn collections; 0% and 2% in the Choptank collections; and 5.6% in the Rhode collection. Liver tumor prevalence was 0% to 6% in all but one South River collection (20%) and 0% to 6% in the three other rivers. In a subset of samples, PAH-like biliary metabolites and (32)P-DNA adducts were used as biomarkers of exposure and response to polycyclic aromatic compounds (PACs). Adducts from alkylating agents were detected as O6-methyl-2'-deoxyguanosine (O6Me-dG) and O6-ethyl-2'-deoxyguanosine (O6Et-dG) modified DNA. Bullheads from the contaminated Anacostia River were used as a positive control for DNA adducts. (32)P-DNA adduct concentrations were significantly higher in Anacostia bullhead livers compared with the other rivers. We identified alkyl DNA adducts in bullhead livers from the South and Anacostia, but not the Choptank. Neither the PAH-like bile metabolite data, sediment PAH data, nor the DNA adduct data suggest an association between liver or skin tumor prevalence and exposure to PACs or alkylating agents in the South, Choptank, Severn, or Rhode rivers. Logistic regression analysis of the Chesapeake Bay database revealed that sex and length were significant covariates for liver tumors and length was a significant covariate for skin tumors.
authors: U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, 177 Admiral Cochrane Drive, Annapolis, MD 21401, USA. Fred_Pinkney@fws.gov
authors: Alfred E
authors: AE
authors: Pinkney
authors: John C
authors: JC
authors: Harshbarger
authors: Natalie K
authors: NK
authors: Karouna-Renier
authors: Kathryn
authors: K
authors: Jenko
authors: Lennart
authors: L
authors: Balk
authors: Halldóra
authors: H
authors: Skarphéðinsdóttir
authors: Birgitta
authors: B
authors: Liewenborg
authors: Michael A
authors: MA
authors: Rutter
mesh_terms: D000477:Alkylating Agents / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D018736:DNA Adducts / Q000032:analysis; D004219:District of Columbia / Q000453:epidemiology; D005260:Female; D005393:Fish Diseases / Q000139:chemically induced* / Q000453:epidemiology / Q000473:pathology; D007059:Ictaluridae; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000139:chemically induced / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D016015:Logistic Models; D008297:Male; D008396:Maryland / Q000453:epidemiology; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism; D015995:Prevalence; D045483:Rivers / Q000737:chemistry; D012867:Skin / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000139:chemically induced / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D014768:Virginia / Q000453:epidemiology
chemical_list: D000477:Alkylating Agents; D015415:Biomarkers; D018736:DNA Adducts; D011084:Polycyclic Aromatic Hydrocarbons