title: Uptake and accumulation of sediment-associated 4-nonylphenol in a benthic invertebrate (Lumbriculus variegatus, freshwater oligochaete).
abstract: In the present work, the oligochaete Lumbriculus variegatus was exposed for 56 d to lake sediment spiked with 4-nonylphenol (4-NP), which is a breakdown product of alkylphenol polyethoxylates, an important class of nonionic surfactants. During the exposure period, the content of 4-NP was determined in the oligochaetes, sediment, overlying water, and pore water in order to monitor the distribution of the 4-NP in the compartments of the test system. Concentration of 4-NP in L. variegatus increased linearly over the course of the test, with an uptake rate coefficient of 1.9 x 10(-2) (+/- 0.2 x 10(-2); [g carbon/(g lipid x h)]). No steady state was reached at the end of the exposure period, suggesting that the elimination of 4-NP by the organism was negligible. Ingested sediments played an important role in the accumulation of 4-NP in L. variegatus, which may achieve very high 4-NP body concentrations. The 56-d biota sediment accumulation factor (BSAF) was 24 +/- 7 g carbon/g lipid. L. variegatus also was exposed to 4-NP-contaminated field sediment, and field oligochaetes and sediments were collected for 4-NP pollution assessment in aquatic ecosystem. The 4-NP uptake with natural sediment was in accordance with that measured with spiked sediments, suggesting that the bioavailability of sediment-associated 4-NP for L. variegatus was not affected by 4-NP sediment concentration and abiotic sediment characteristics. The BSAFs measured in field oligochaetes, ranging from 39 to 55 g carbon/g lipid, was relatively higher than the bioaccumulation factor measured in laboratory tests. The results suggest that 4-NP concentration can reach high levels in benthic oligochaetes; this can be an important way of exposure for their pelagic predators.
authors.affiliation: Department of Chemical, Physical and Mathematical Sciences, University of Insubria, Via Valleggio 11, I-22100, Como, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Croce
authors.forename: Silvia
authors.initials: S
authors.lastname: De Angelis
authors.forename: Luisa
authors.initials: L
authors.lastname: Patrolecco
authors.forename: Stefano
authors.initials: S
authors.lastname: Polesello
authors.forename: Sara
authors.initials: S
authors.lastname: Valsecchi
mesh_terms: D033304:Amphipoda / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D002244:Carbon / Q000378:metabolism; D019015:Geologic Sediments / Q000737:chemistry*; D007448:Invertebrates / Q000187:drug effects* / Q000378:metabolism; D050356:Lipid Metabolism; D009835:Oligochaeta / Q000187:drug effects / Q000378:metabolism; D010636:Phenols / Q000378:metabolism / Q000633:toxicity*; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D010636:Phenols; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D002244:Carbon; C041594:4-nonylphenol