Da. Bright et al., DIFFERENTIAL BIOACCUMULATION OF NON-ORTHO-SUBSTITUTED AND OTHER PCB CONGENERS IN COASTAL ARCTIC INVERTEBRATES AND FISH, Environmental science & technology, 29(10), 1995, pp. 2504-2512
The composition of 47 ortho- and seven non-ortho-substituted PCBs in s
ediment, water, invertebrates, and fish collected from Cambridge Bay,
Northwest Territories, Canada, is presented. The congener composition
in sea urchins (Strongylocentrotus droebachiensis) was attributed to d
ifferences in the log K-ow of individual congeners during uptake from
ingested sediment and aqueous solubility during secondary uptake from
the water column. Four-horn and short-horn sculpins exhibited selectiv
e bioaccumulation of the recalcitrant congeners: those lacking two non
-chlorinated carbons in adjacent meta and para positions on the biphen
yl ring. The presence of methyl sulfone PCBs in four-horn sculpin live
r provided direct evidence for metabolism. The percent composition of
total PCB levels in four-horn sculpin livers, contributed by non-ortho
-substituted PCBs 77 and 126 (those with potential for dioxin-like tox
icity), was relatively constant regardless of total PCB concentration,
suggesting that for a given species increased exposure to PCBs does n
ot lead to increased relative concentrations of non-ortho-substituted
congeners. Limited data on congeners 77 and 126 in sediment, sea urchi
ns, or four-horn sculpins suggests that, with increasing trophic statu
s, these congeners were diminished rather than enriched relative to th
e total PCB concentration.