Uptake and depuration of nonionic organic contaminants from sediment by the oligochaete, Lumbriculus variegatus.
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.
Ingersoll
Christopher G
CG
Columbia Environmental Research Center, US Geological Survey, 4200 New Haven Road, Columbia, Missouri 65201, USA. chris_ingersoll@usgs.gov
Brunson
Eric L
EL
Wang
Ning
N
Dwyer
F James
FJ
Ankley
Gerald T
GT
Mount
David R
DR
Huckins
James
J
Petty
Jim
J
Landrum
Peter F
PF
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
D012989:Soil Pollutants; D003633:Dichlorodiphenyl Dichloroethylene; D003634:DDT; D003632:Dichlorodiphenyldichloroethane