title: Uptake and depuration of nonionic organic contaminants from sediment by the oligochaete, Lumbriculus variegatus.
abstract: Uptake of sediment-associated contaminants by the oligochaete Lumbriculus variegatus was evaluated after 1, 3, 7, 14, 28, and 56 d of exposure to a field-collected sediment contaminated with DDT and its metabolites, dichlorodiphenyldichloroethane (DDD) and dichlorodiphenyldichloroethylene (DDE), or to a field-collected sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Depuration of contaminants by oligochaetes in a control sediment or in water was also evaluated over a 7-d period after 28 d of exposure to the field-collected sediments. Accumulation of PAHs with a log octanol-water partitioning coefficient (log Kow) <5.6 typically reached a peak at day 3, followed by a lower plateau between days 7 and 56 of the sediment exposure. Similarly, 4,4'-DDT exhibited a peak in accumulation at day 14 followed by a decline at days 28 and 56. In contrast, accumulation of PAHs with a log Kow >5.6 or DDD and DDE typically exhibited a steady increase from day 1 to about day 14 or 28, followed by a plateau. Therefore, exposures conducted for a minimum of 14 to 28 d better reflected steady-state concentrations for DDT and its metabolites and for PAHs. Depuration rates for DDT and its metabolites and high-Kow PAHs were much higher in organisms held in clean sediment relative to both water-only depuration and model predictions. This suggests that depuration in clean sediment may artificially accelerate depuration of hydrophobic compounds. Comparisons between laboratory-exposed L. variegatus and oligochaetes collected in the field from these sediments indicate that results of laboratory tests can be extrapolated to the field with a reasonable degree of certainty.
authors.affiliation: Columbia Environmental Research Center, US Geological Survey, 4200 New Haven Road, Columbia, Missouri 65201, USA. chris_ingersoll@usgs.gov
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Ingersoll
authors.forename: Eric L
authors.initials: EL
authors.lastname: Brunson
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: F James
authors.initials: FJ
authors.lastname: Dwyer
authors.forename: Gerald T
authors.initials: GT
authors.lastname: Ankley
authors.forename: David R
authors.initials: DR
authors.lastname: Mount
authors.forename: James
authors.initials: J
authors.lastname: Huckins
authors.forename: Jim
authors.initials: J
authors.lastname: Petty
authors.forename: Peter F
authors.initials: PF
authors.lastname: Landrum
mesh_terms: D000818:Animals; D003634:DDT / Q000378:metabolism; D003633:Dichlorodiphenyl Dichloroethylene / Q000378:metabolism; D003632:Dichlorodiphenyldichloroethane / Q000378:metabolism; D019015:Geologic Sediments / Q000737:chemistry*; D009835:Oligochaeta / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*; D013997:Time Factors
chemical_list: D012989:Soil Pollutants; D003633:Dichlorodiphenyl Dichloroethylene; D003634:DDT; D003632:Dichlorodiphenyldichloroethane