Halogenated Contaminants in Farmed Salmon, Trout, Tilapia, Pangasius, and Shrimp

Polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzo-p-furans (PCDD/Fs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane diastereomers (HBCDs), and perfluorinated compounds (PFCs) were analyzed in popular farmed fish such as salmon, trout, tilapia, and pangasius and in farmed shrimp. The samples originated from southeast Asia, Europe, and South America, Results show the following: (i) Carnivorous species contained higher contaminant concentrations than omnivorous species. (ii) Contaminant concentrations generally decreased per species in the following order of salmon > trout >> tilapia approximate to pangasius approximate to shrimp. (iii) Most contaminant concentrations decreased in the following order of PCBs approximate to dichloro-diphenyl-trichloroethanes (DDTs) >> hexachlorobenzene approximate to pentachlorobenzene approximate to dieldrin approximate to PBDEs approximate to alpha-HBCD approximate to perfluorooctane sulfonate (PFOS) >> World Health Organization toxic equivalents (WHO-TEQ) [PCDD/Fs and dioxin-like (dl)-PCBs]. (iv) Contaminant concentrations were very low (mostly <1 ng/g wet weight) and far below the European and Dutch legislative limits. (v) Contaminant concentrations in farmed shrimp, pangasius, and tilapia were lower than those in wild fish, whereas contaminant concentrations in farmed salmon and trout were higher than those in lean wild marine fish. From the five species investigated, salmon is predominantly responsible (97%) for human exposure to the sum of the investigated contaminants. The contribution of trout, tilapia, pangasius, and shrimp is small (3%) because contaminant concentrations and consumption volumes were much lower.