title: Effects of dissolved organic material on binding and toxicokinetics of pyrene in the waterflea Daphnia magna.
abstract: The binding and bioavailability of pyrene was studied in the laboratory in two humic fresh waters and in a reference water without dissolved organic material (DOM), measured as dissolved organic carbon (DOC). The uptake of pyrene by Daphnia magna in short-term (24 h) accumulation experiments was fitted to a first-order rate-kinetic equation to calculate simultaneous uptake and elimination rates. The partition coefficients of pyrene to DOC (KDOC) were 37.1 x 103 in Pielisjoki River (9.4 mg DOC L(-1)), and 34.9 x 103 in Lake Kontiolampi (17.4 mg DOC L(-1)) waters, indicating similar binding affinities of pyrene for both humic waters. The uptake clearance of pyrene (ku) in the DOC-rich Lake Kontiolampi water was 290.4 ml g wet weight(-1) h(-1), which was lower than those in Pielisjoki River and DOC-free waters (395.8 and 346.0 ml g wet weight(-1) h(-1), respectively). Pyrene elimination (ke) was in average 0.2 h(-1) with no significant differences between the waters. The observed bioconcentration factors of pyrene in Pielisjoki River and Lake Kontiolampi waters were 84% and 46% of that in the DOC-free reference water, respectively, thus indicating that a high concentration of DOC is needed to decrease the bioavailability of waterborne pyrene to D. magna.
authors.affiliation: Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FIN-40351 Jyväskylä, Finland. annikkil@dodo.juyu.fi
authors.forename: A
authors.initials: A
authors.lastname: Nikkilä
authors.forename: J V
authors.initials: JV
authors.lastname: Kukkonen
mesh_terms: D000818:Animals; D001682:Biological Availability; D003621:Daphnia; D005456:Fluorescent Dyes / Q000737:chemistry / Q000493:pharmacokinetics* / Q000633:toxicity; D009930:Organic Chemicals; D011721:Pyrenes / Q000737:chemistry / Q000493:pharmacokinetics* / Q000633:toxicity; D012995:Solubility; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics* / Q000633:toxicity
chemical_list: D005456:Fluorescent Dyes; D009930:Organic Chemicals; D011721:Pyrenes; D014874:Water Pollutants, Chemical; C030984:pyrene