Hazardous implications of halogenated polycyclic aromatic hydrocarbons in feedstuff: Congener specificity and toxic levels in feed ingredients and feeds.

ABSTRACT

Studies have shown that halogenated polycyclic aromatic hydrocarbons (HPAHs), including chlorinated (ClPAHs) and brominated PAHs (BrPAHs), could be hazardous pollutants due to their pervasive occurrence in the environment. However, their accumulation properties and toxic potentials in animal feedstuffs remain unclear. This study investigated 75 congeners of parent PAHs, ClPAHs, and BrPAHs in animal-based feed ingredients and fish and swine feeds in Japan using a GC/Orbitrap MS system. The total parent PAHs ranged from below the method detection limit (lipid weight (l.w.), with the highest concentration found in fish oil. The total ClPAHs and BrPAHs were in the ranges of meal. The maximum detection frequencies for parent PAHs, ClPAHs, and BrPAHs were detected for fluorene (75 %), trichloropyrene (86 %), and 2-bromonaphthalene (97 %), respectively. The highest ClPAH concentrations were dominated by dichloropyrene (61.92 ng/g l.w., fish meal). The BrPAHs were mostly contributed by 1-bromonaphthalene (33.94 ng/g l.w., animal fat) and 2-bromonaphthalene (22.37 ng/g l.w., fish meal). The toxic assessment estimated for target compounds in various feed ingredients and feed based on the toxic equivalency quotients (TEQs) revealed that HPAHs could additively contribute (up to 100 %) to PAH-like toxic effects. Despite their high detection frequencies and concentrations, several ClPAHs and BrPAHs had no relative toxic potency values. Thus, the TEQs were underestimated, indicating that urgent in-depth research is required to obtain toxicological data for predominant HPAHs.