Impacts of cooking technique on polychlorinated biphenyl and polychlorinated dioxins/furan concentrations in fish and fish products with intake estimates.

Polychlorinated biphenyl (PCB) and polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) concentrations were determined in composites of 18 different fish products and were prepared as raw, baked, boiled, and fried. ∑PCB concentrations were found to range from 0.12 ng·g(-1) whole weight (ww) in raw octopus to 33 ng·g(-1) ww in baked mackerel. Boiled monkfish was found to have the lowest ∑PCDD/F concentrations (0.41 pg·g(-1) ww), while maximum concentrations were observed in fried catfish (59 pg·g(-1) ww). PCB and PCDD/F concentrations in fish were generally reduced during cooking, although differences were small. The average PCB reduction in finfish was 7.9%, while an increase in PCB mass was observed in non-finfish (2.9%). PCDD/F losses, on average, were observed in both the finfish (3.6%) and non-finfish products (25%). Maximum ∑PCB, ∑PCDD/F, and TEQ(PCDD/F+DL-PCB) (toxic equivalency) intakes, based on 150 g serving size, were determined to be 3300 ng (mackerel), 6600 pg (catfish), and 270 pg (catfish), respectively. PCB and PCDD/F changes associated with cooking generally were small (<15%), although larger mean differences (∼40%) were observed in some fish products (e.g., catfish).

PCB, PCDD and PCDF residues in fin and non-fin fish products from the Canadian retail market 2002.

Fish products (n=129) available on the Canadian retail market were collected and analyzed for levels of PCBs, PCDDs and PCDFs during the spring of 2002. The collection included samples from eight fish groups (Arctic char, crab, mussels, oysters, salmon, shrimp, tilapia, trout) from the wild and those raised on fish farms, as available. Sample collection included both domestic and imported fish products, however, no significant difference in residue levels was observed between these groups of fish products. Salmon samples were found to contain the highest concentration of sigmaPCBs (geometric mean 12.9 ng/g wet weight), while crab samples had greatest sigmaPCDD/F levels (geometric mean 0.002 ng/g wet weight). The geometric mean of the total toxic equivalents (WHO-TEQ) ranged from 0.06 pg WHO-TEQ/g whole weight in farmed shrimp to 1.1 pg WHO-TEQ/g whole weight in farmed salmon samples. PCB 153, 138, 118 and 101 were the dominant congeners observed in fish product samples studied, while 1,2,3,7,8-pentachlorodibenzodioxin and 2,3,7,8-tetrachlorodibenzofuran contributed the most to total PCDD and PCDF loadings. Lipid content was positively correlated to sigmaPCB levels; however, no relationship between lipid content and sigmaPCDD/F concentrations was established. SigmaPCB levels were below the Canadian guideline value for PCBs in fish and fish products (2000 ng/g). Similarly, 2,3,7,8-TCDD levels in all fish products were below the Canadian guideline value (0.020 ng/g).

Polybrominated diphenyl ethers in retail fish and shellfish samples purchased from Canadian markets.

Fish and shellfish retail samples (n = 122) were purchased from three Canadian cities in the winter of 2002 and analyzed for a total of 18 polybrominated diphenyl ether (PBDE) congeners. The samples (salmon, trout, tilapia, Arctic char, mussels, oysters, shrimp, and crab) represented the range of fish and shellfish commercially available to Canadian consumers at the time of purchase. Trout and salmon (geometric mean SigmaPBDE = 1600 and 1500 pg/g, wet weight, respectively) were found to contain significantly higher amounts of PBDEs than the mussel, tilapia, and shrimp groups (geometric mean SigmaPBDE = 260, 180, and 48 pg/g, wet weight, respectively). These differences in SigmaPBDE concentrations among fish and shellfish products were partly driven by differences in lipid content among the samples. Mean SigmaPBDE concentrations in domestic samples were also significantly greater than in imported samples, possibly reflecting global environmental distribution of PBDEs. These concentration differences will contribute to variations in dietary exposure to PBDEs when assorted fish and shellfish items from various origins are consumed.