Levels of Polychlorinated Biphenyls (PCBs) and Three Organochlorine Pesticides in Fish from the Aleutian Islands of Alaska

Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and chlorinated pesticides, have been shown to have many adverse human health effects. These contaminants therefore may pose a risk to Alaska Natives that follow a traditional diet high in marine mammals and fish, in which POPs bioaccumulate.This study examined the levels of PCBs and three pesticides [p, p'-DDE, mirex, and hexachlorobenzene (HCB)] in muscle tissue from nine fish species from several locations around the Aleutian Islands of Alaska. The highest median PCB level was found in rock sole (Lepidopsetta bilineata, 285 ppb, wet weight), while the lowest level was found in rock greenling (Hexagrammos lagocephalus, 104 ppb, wet weight). Lipid adjusted PCB values were also calculated and significant interspecies differences were found. Again, rock sole had the highest level (68,536 ppb, lipid weight). Concerning the PCB congener patterns, the more highly chlorinated congeners were most common as would be expected due to their greater persistence. Among the pesticides, p, p'-DDE generally dominated, and the highest level was found in sockeye salmon (Oncorhynchus nerka, 6.9 ppb, wet weight). The methodology developed by U.S. Environmental Protection Agency (USEPA) was used to calculate risk-based consumption limits for the analyzed fish species. For cancer health endpoints for PCBs, all species would trigger strict advisories of between two and six meals per year, depending upon species. For noncancer effects by PCBs, advisories of between seven and twenty-two meals per year were triggered. None of the pesticides triggered consumption limits.The fish analyzed, mainly from Adak, contain significant concentrations of POPs, in particular PCBs, which raises the question whether these fish are safe to eat, particularly for sensitive populations. However when assessing any risk of the traditional diet, one must also consider the many health and cultural benefits from eating fish

Consumption advisories for cancer health effects based on concentrations of PCBs and the mixture of PCB, HCB, and DDE+85, respectively.

<p>The advisories are in meals/year and are based on USEPA cancer slope factors (CSF). The species are arranged after recommended meals per year in ascending order. ROSO, rock sole. PCOD, Pacific cod. SCUL, great sculpin. FLSO, flathead sole. SALM, sockeye salmon. DOLL, dolly varden. ROCK, rock greenling.</p

Contaminant levels and p values of the fish species included in the statistical analysis.

<p>Concentrations are in ng/g (ppb), wet weight.</p>a<p>Significant differences² were found between the following species for each of the contaminants below.</p><p>Total PCBs, lipid adjusted.</p><p>Rock sole and sockeye salmon (p = 0.004).</p><p>Flathead sole and sockeye salmon (p<0.002).</p><p>Great sculpin and sockeye salmon (p<0.002).</p><p>Pacific cod and sockeye salmon (p = 0.01).</p><p>Rock sole and dolly varden (p = 0.02).</p><p>Flathead sole and dolly varden (p = 0.01).</p><p>Pacific cod and dolly varden (p = 0.03).</p><p>HCB.</p><p>Sockeye salmon and flathead sole (p = 0.002).</p><p>Dolly varden and flathead sole (p = 0.004).</p><p>Great sculpin and flathead sole (p = 0.004).</p><p>Pacific cod and flathead sole (p = 0.03).</p><p>Mirex.</p><p>Rock sole and flathead sole (p = 0.03).</p><p>Rock sole and dolly varden (p = 0.02).</p><p>Rock sole and great sculpin (p = 0.04).</p><p>Rock sole and rock greenling (p = 0.04).</p>1<p>Kruskal-Wallis test.</p>2<p>Wilcoxon rank-sum test.</p

USEPA risk values [43], used in risk-based consumption limits.

1<p>Reference Dose.</p>2<p>Cancer Slope Factor.</p>3<p>Not available.</p

Consumption advisories for noncancer health effects based on PCB concentrations.

<p>The advisories are in meals/year and based on USEPA reference dose (RfD). The species are arranged after recommended meals per year in ascending order. ROSO, rock sole. PCOD, Pacific cod. SCUL, great sculpin. FLSO, flathead sole. SALM, sockeye salmon. DOLL, dolly varden. ROCK, rock greenling.</p

Trophic level and lipid content of the analyzed fish species.

1<p>Not available.</p

Average PCB congener pattern.

<p>The values are expressed as percent of total PCBs. Black rockfish and Pacific halibut were excluded from the calculations.</p

Consumption advisories for cancer health effects based on total TEQ.

<p>The advisories are in meals per year and calculated for the analyzed 5 out of 12 dioxin-like PCB congeners. The calculations are based on USEPA cancer slope factors (CSF). PCOD, Pacific cod. SCUL, great sculpin. SALM, sockeye salmon. ROSO, rock sole. FLSO, flathead sole. DOLL, dolly varden. ROCK, rock greenling.</p

Box plot showing total PCB concentrations.

<p>Concentrations are in ng/g (ppb), wet weight. The box represents 50 percent of the values. The median, as well as the sample maximum (excluding outliers) and minimum are shown. Outliers are represented by dots. The species are arranged after median values in ascending order. Black rockfish and Pacific halibut were excluded. ROCK, rock greenling. DOLL, dolly varden. PCOD, Pacific cod. SALM, sockeye salmon. SCUL, great sculpin. FLSO, flathead sole. ROSO, rock sole.</p

Box plot showing lipid adjusted total PCB levels.

<p>Concentrations are in ng/g (ppb), lipid weight. The box represents 50 percent of the values. The median, as well as the sample maximum (excluding outliers) and minimum are shown. Outliers are represented by dots. The species are arranged after median values in ascending order. Black rockfish and Pacific halibut were excluded. SALM, sockeye salmon. DOLL, dolly varden. ROCK, rock greenling. SCUL, great sculpin. PCOD, Pacific cod. FLSO, flathead sole. ROSO, rock sole.</p