Polychlorinated naphthalenes (PCNs) in food products in Latvia: Congener-specific analysis, occurrence, and dietary exposure of the general population

A study was performed to evaluate the dietary exposure of the Latvian population to polychlorinated naphthalenes (PCNs). Based on the toxicological characteristics, provisional levels of occurrence, congener patterns, and the availability of analytical standards, twenty-six congeners were included in the analysis. Considering the planar structure of PCNs, an analytical protocol on the basis of destructive clean-up and isolation of analytes on carbon was applied, while GC-HRMS and isotope dilution were used for the detection and quantification of analytes. Commonly consumed foods were analyzed for the content of PCNs, followed by per capita intake calculations. By applying the available in vitro relative potency (REP) factors, putative toxic equivalents (TEQ) were determined, in order to assess the "dioxin-like" effect arising from the presence of PCNs in food. The daily intake (EDI) for total PCNs (Sigma(PC)(N)) and PCN-TEQ for the general population were calculated to be 116 pg kg(-1) body weight (b.w.) and 0.036 pg TEQ kg(-1) b.w., respectively. Fish and fish products were found to provide the main contribution to the dietary "dioxin-like" burden of PCNs, constituting similar to 60% of the total PCN-TEQ intake. For some fish samples, PCN-TEQ could additionally contribute up to similar to 3% to the regulated PCDD/F-PCB-TEQ while for other matrices this contribution could be lower by an order of magnitude. The obtained data indicated that the estimated dietary exposure to PCNs is likely to be of low concern, although PCN-TEQ could be recognized as a contributor to the overall "dioxin-like" TEQ loading that results from the exposure to halogenated aromatics. (C) 2020 Elsevier Ltd. All rights reserved.