Preferential Biomagnification of Aryl Hydrocarbon Hydroxylase–inducing Polychlorinated Biphenyl Congeners in the Lake Michigan, Usa, Lower Food Web

Abstract

Preferential biomagnification of 14 dioxin-like polychlorinated biphenyls (PCBs) was determined in lower-trophic-level organisms of the Lake Michigan, USA, food web. Bioaccumulation of these coplanar, aryl hydrocarbon hydroxylase (AHH)-inducing PCB congeners and total PCBs in phytoplankton, zooplankton, Mysis relicta, and Diporeia sp. were studied for two locations in Lake Michigan over time. The results indicate that both total PCB and AHH-inducing PCBs biomagnify with increasing food web trophic level, with biomagnification of the AHH-inducing PCBs occurring to a greater degree. The biomagnification factors (BMFs) of the AHH-inducing PCBs suggest that they are highly conserved relative to other PCB congeners. The concentrations expressed as dioxin toxic equivalencies (TEQ concentrations) indicate that the biomagnification of AHH PCBs causes greater concentrations, and thus greater toxicity risk, with increasing trophic level.

Bioaccumulation and trophic transfer of polychlorinated biphenyls by aquatic and terrestrial insects to tree swallows (Tachycineta bicolor)

“…This is lower than the BSAF of 9.3 reported previously for the ⌺PCB in nestlings [2]. The nestling BSAF value for ⌺TEQ in the present study was slightly higher than that for ⌺PCB, which supports the hypothesis that dioxin-like congeners may exhibit differential bioaccumulation relative to other congeners [29,30]. However, for the three mono-ortho-substituted PCB congeners examined here (i.e., PCB congeners 105, 118, and 156), BSAF values ranged from the highest to the lowest among all congeners.…”

Accumulation of polychlorinated biphenyls from floodplain soils by passerine birds

“…Relative potency and potency ratios calculated for birds were intended to describe the increase or decrease in toxicity of the PCB mixture at the study locations. Potency ratios greater than 1.0 were observed for most comparisons, which suggests that the mixture of congeners in the food chain become more potent at increasingly greater trophic levels through the bioaccumulation of aryl hydrocarbon receptor-active congeners [30]. Relative potencies at FC were influenced by several samples with low concentrations of PCBs or concentrations of TEQs WHO-Avian driven by the detection limit of the analytical method.…”

Polybrominated diphenyl ethers (PBDEs) in Lake Michigan forage fish

“…PCB concentrations in Diporeia have been found to be anywhere from two to ten times higher in Diporeia than in Mysis (Manchester-Neesvig et al 2001, Stapleton et al 2002, Trowbridge and Swackhamer 2002. Given the similar physical-chemical properties of PBDEs and PCBs, Diporeia would be expected to have relatively high PBDE levels.…”