Lethal and sublethal body residues for PCB intoxication in the oligochaete, Lumbriculus variegatus

The oligochaete, Lumbriculus variegatus, was used to examine the utility of critical body residues in describing lethal and sublethal chronic endpoints during polychlorinated biphenyls (PCB) exposure. L. variegatus was exposed to four C-14-PCB congeners and 2,2-bis-(p-chlorophenyl)-1,1-dichloroethylene (DDE) on algal cells. Accumulation and resulting effects were monitored in 10-day acute and 35-day chronic exposures. L. variegatus was resistant to the acute lethal narcotic effects of these contaminants and no mortality was obtained in 10-day exposures. However, mortality that was significantly different from unexposed controls occurred for four compounds in 35-day assays; average body residues for chronic mortality were consistent among contaminants (0.88-1.35 mmol kg(-1)). Kinetic studies showed that failure to generate mortality in some exposures was due to rapid elimination. Mono-2-chlorobiphenyl, for instance, had a K-d of 0.22 h(-1) which was seven to 44 times faster than for the other contaminants. Sublethal reductions in body mass and reproduction occurred at lower body residues than were needed to produce mortality (0.34-0.56 mmol kg(-1)). The consistency of the sublethal data suggests that they may offer a means of interpreting residue data for PCBs in the environment. (C) 1999 Elsevier Science B.V. All rights reserved.