Polychlorinated biphenyls and their hydroxylated metabolites in wild fish from wheatley Harbour Area of Concern, Ontario, Canada

Abstract

Whole-body polychlorinated biphenyls (ΣPCBs) and plasma hydroxylated PCBs (OH-PCBs) concentrations were determined in brown bullhead (Ameiurus nebulosus) from Wheatley Harbour, Ontario, Canada. Elevated ΣPCBs in Wheatley Harbour are suspected to have originated from industrial waste disposal and/or discharges from nearby fish processing through discarding of fish remains. Mean ΣPCB concentrations in brown bullhead from Wheatley Harbour were approximately 250 ng/g wet weight compared with approximately 40 ng/g wet weight for brown bullhead from the reference sites, Hillman Marsh and Turkey Creek (both in Ontario, Canada). A significant relationship was found between the concentrations of non-ortho and mono-ortho PCB concentrations (toxic equivalents) and liver mixed-function oxygenase in brown bullhead (r = 0.74, p < 0.001). Plasma OH-PCB concentrations were greater in Wheatley Harbour brown bullhead than in those from Hillman Marsh (3.6 vs 1.5 ng/g wet wt, p < 0.01), and were detected infrequently in those from Turkey Creek (0.1 ng/g wet wt, n = 2). The OH-PCB congeners most frequently detected were 4'-OH-CB172, 3'-OH-CB180, 4-OH-CB187, 4-OH-CB146, 3-OH-CB138, and 4-OH-CB130, which are structurally similar to the thyroid hormones. To test the hypothesis of fish waste as the cause of the observed PCB contamination of Wheatley Harbour brown bullhead, a principal component analysis (PCA) was used to compare the brown bullhead PCB congener data with equivalent data for Lake Erie walleye, Lake Erie sediment, and industrial Aroclor mixtures. The relative proportions of each Aroclor mixture were estimated using the conjugated gradient method. The high similarity between the congener signatures for Lake Erie walleye and Wheatley Harbour brown bullhead supports the hypothesis of contamination from the fish processing industry.

Assessment of the health status of wild fish from the wheatley Harbour area of Concern, Ontario, Canada

“…In a companion study, we report elevated concentrations of whole-body PCBs and plasma hydroxylated PCBs in brown bullhead from Wheatley Harbour, compared with Hillman Marsh [13], the results of which lend support to the observed differences in the health and endocrine status of fish observed here. In a companion study, we report elevated concentrations of whole-body PCBs and plasma hydroxylated PCBs in brown bullhead from Wheatley Harbour, compared with Hillman Marsh [13], the results of which lend support to the observed differences in the health and endocrine status of fish observed here.…”

“…The harbor's average water depth is 2.5 to 3 m, and is subject to periodic flushing by the inflowing Muddy Creek and seiche from Lake Erie [14]. Chemical analysis data revealed that these fish had average PCB body burdens of 250 ng/g wet weight, more than five times greater than those of Hillman Marsh (40 ng/g wet wt) [13]. Hoop nets were deployed in Muddy Creek directly north of the harbor, in the deepest location ($1 m depth).…”

Halogenated phenolic compounds in wild fish from Canadian Areas of Concern

“…In contrast, plasma samples from the Wheatley Harbour AOC also contained approximately 30% heptachloro OH‐PCBs; and while these were also detected in Toronto and Bay of Quinte AOCs, the concentrations represented at most 3% of the homologs detected (Figure ). This suggests a different (more highly chlorinated) source of PCB contamination, thought to have been from release of fish waste from fish processing facilities directly into the small harbor, until the mid‐1980s, a hypothesis investigated and discussed in Gilroy et al . Monochloro and dichloro OH‐PCBs were generally not detected, except in the Toronto and Region AOC, albeit at very low concentrations (representing at most just over 1% of the homologs detected).…”

“…Similarly, in their study with the same fish from the Bay of Quinte AOC, Simmons et al reported elevated body concentrations of coplanar PCBs in brown bullhead from Belleville and Trenton compared with those from Deseronto. In general, greater PCB concentrations were associated with larger urban centers, with the exception of Muddy Creek (Wheatley Harbour AOC), which exhibited an exceptional contamination profile, discussed in Gilroy et al . In a study investigating concentrations of halogenated phenolic compounds in the plasma of snapping turtles ( Chelydra serpentina ) from Canadian AOCs, Letcher et al reported concentrations of PCBs in the range of 100 ng/g to 200 ng/g wet weight in the Detroit River, Wheatley Harbour, and Bay of Quinte AOCs.…”

A computational approach predicting CYP450 metabolism and estrogenic activity of an endocrine disrupting compound (PCB-30)

“…Polychlorinated biphenyl-30 has previously been shown as only weakly active toward the hER-a protein but increasing in activity after being metabolized into hydroxylated forms [22,23]. Polychlorinated biphenyl-30 has previously been shown as only weakly active toward the hER-a protein but increasing in activity after being metabolized into hydroxylated forms [22,23].…”