title: A bio-effect directed fractionation study for toxicological and chemical characterization of organic compounds in bottom sediment.
abstract: The major aim of this study was to characterize toxic organic compounds in bottom sediments from a PCB polluted bay. To overcome difficulties in pinpointing toxicants in complex environmental samples we applied a bio-effect directed (BED) fractionation approach and investigated the relationships between aromaticity, teratogenicity, and aryl hydrocarbon receptor (AhR) mediated toxicity. Hepatic ethoxyresorufin O-deethylase (EROD) activities and malformations were investigated in rainbow trout (Oncorhynchus mykiss) larvae exposed by injecting sediment extract and fractions (separated by their degree of aromaticity) thereof into newly fertilized eggs. Our results imply that non-additive effects get more pronounced the more complex the exposure. The fraction mainly composed of dicyclic aromatic compounds (DACs), including PCBs, was surprisingly less teratogenic than the fraction mainly composed of polycyclic aromatic compounds (PACs). A major part of the latter potential was isolated in a subfraction mainly composed of three- and four-ring compounds (including alkylated and sulphur-heterocyclic compounds). Though no clear relationship between aromaticity and EROD induction was observed, both the DAC- and the PAC-fractions contributed equally to the EROD induction potential. A major part of the PAC-fraction's induction potential came from a subfraction containing compounds with more than five rings. No clear relationship between teratogenicity and EROD induction was observed, underlining the need for a battery of biomarkers in estimating environmental risk. Two specific malformations not previously described in literature-asymmetric yolk sac and fin edema-could be tracked through the fractionation steps, suggesting that this BED-fractionation strategy is a reliable tool for pinpointing toxic compounds in the environment.
authors.affiliation: Department of Applied Environmental Research (ITM), Stockholm University, SE-106 91 Stockholm, Sweden, and County Administrative Board of Stockholm, SE-104 22 Stockholm, Sweden. henrik.sundberg@itm.su.se
authors.forename: Henrik
authors.initials: H
authors.lastname: Sundberg
authors.forename: Rasha
authors.initials: R
authors.lastname: Ishaq
authors.forename: Gun
authors.initials: G
authors.lastname: Akerman
authors.forename: Ulla
authors.initials: U
authors.lastname: Tjärnlund
authors.forename: Yngve
authors.initials: Y
authors.lastname: Zebühr
authors.forename: Maria
authors.initials: M
authors.lastname: Linderoth
authors.forename: Dag
authors.initials: D
authors.lastname: Broman
authors.forename: Lennart
authors.initials: L
authors.lastname: Balk
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000473:pathology; D000818:Animals; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis; D019015:Geologic Sediments / Q000737:chemistry*; D007814:Larva; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D017686:Oncorhynchus mykiss; D009930:Organic Chemicals / Q000737:chemistry* / Q000633:toxicity*; D010063:Ovum / Q000187:drug effects; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity; D013329:Structure-Activity Relationship; D013723:Teratogens / Q000633:toxicity; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity*
chemical_list: D009930:Organic Chemicals; D011084:Polycyclic Aromatic Hydrocarbons; D013723:Teratogens; D014874:Water Pollutants, Chemical; D019363:Cytochrome P-450 CYP1A1