Bioenergetics-based modeling of individual PCB congeners in nestling tree swallows from two contaminated sites on the upper Hudson River, New York.
A bioenergetics-based model was used to simulate the accumulation of total PCBs and 20 PCB congeners by nestling tree swallows at two contaminated sites on the Upper Hudson River, New York. PCB concentrations in birds were calculated as the sum of inherited residues and those acquired through consumption of contaminated insects. Close agreement between simulations and measured residues in 5-, 10-, and 15-day-old nestlings was obtained when PCB concentrations in the diet were set equal to those in food boli taken from adult birds. These simulations were further optimized by fitting the value of a dietary assimilation efficiency constant. Fitted constants for both sites were similar and averaged about 0.7. An evaluation of model performance for individual congeners provided no evidence of metabolic biotransformation. The results of this study are consistent with a companion effort in which principal components analysis was used to compare PCB congener patterns in insects and in tree swallow eggs, nestlings, and adults. Together, these studies establish a quantitative linkage between nestling tree swallows and the insects that they consume and provide strong support for the use of nestling swallows as a biomonitoring species for exposure assessment.
Nichols
John W
JW
US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, Duluth, Minnesota 55804, USA. nichols.john@epa.gov
Echols
Kathy R
KR
Tillitt
Donald E
DE
Secord
Anne L
AL
McCarty
John P
JP
D000818:Animals; D000831:Animals, Newborn; D001711:Biotransformation; D001835:Body Weight / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D005618:Fresh Water; D007313:Insecta / Q000737:chemistry; D008954:Models, Biological; D009518:New York; D010063:Ovum / Q000737:chemistry; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity; D018570:Risk Assessment; D013045:Species Specificity; D046388:Swallows / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity
D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls