The occurrence of Dechlorane Plus and related norbornene-based flame retardants in Baltic wild salmon (Salmo salar)

Twenty five Baltic wild salmon (Salmo salar) specimens were analysed for the content of Dechlorane-related compounds (DRCs). Out of the ten analysed DRCs, seven compounds were detected in the muscle tissues of salmon, including Dechlorane (Dec) 602, Dec 603, syn- and anti-stereoisomers of Dechlorane Plus (DP), Dechlorane Plus monoadduct (1,3-DPMA), hexachlorocyclopentadienyl-dibromocyclooctane (DBHCTD), and Mirex. The concentrations of Dec 604 and two DP dechlorinated compounds - decachloropentacyclooctadecadiene (Cl10DP) and undecachloropentacyclooctadecadiene (Cl11DP) - were below the limit of detection in all samples. The aggregated concentrations of DRCs (σ_DRC) were in the range of 551-3339 pg g^-1 fresh weight (f.w.) with 1,3-DPMA being the predominant DRC component contributing up to 70% to the σ_DRC. The fractional abundance of syn- and anti-DP stereoisomers showed a pronounced enrichment of anti-DP and was close to the composition of OxyChem^® DP commercial product. The obtained concentrations of DRCs were substantially lower than those reported in previous studies of biotic samples (among them fish, mollusks, white stork and peregrine falcon eggs) from inland freshwater reservoirs in more industrialised areas throughout Europe and North America. A statistically significant relationships between the concentrations of Dec 602 and the concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) was observed.