Current status of short- and medium chain polychlorinated n-alkanes in top predatory fish across Canada

• Published in: Chemosphere (Oxford) 2015-05, Vol.127, p.93-100
• Main Authors: Saborido Basconcillo, Libia, Backus, Sean M., McGoldrick, Daryl J., Zaruk, Donna, Sverko, Ed, Muir, Derek C.G.
• Format: Article
• Language: English
• Subjects: Alkanes - analysis; Animals; Atmospheric transport; Atmospherics; Canada; Chains; Chlorinated paraffins; Fish; Food Chain; Homologue group patterns; Homology; Hydrocarbons, Chlorinated - analysis; Industrial development; Lake Huron; Lake Ontario; Lakes; Polychlorinated n-alkanes; Trout; Water Pollutants, Chemical - analysis
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2015.01.016

•Short and medium chain PCAs were measured in fish from nine water bodies in Canada.•Highest sPCAs levels were measured in sites where atmospheric transport is suspected.•Highest mPCAs levels were found in the highly industrialized/urbanized Great Lakes.•sPCAs decreased 6.6-fold in Lake Ontario lake trout in the last ten years.•Homologue groups patterns in fish aids in the identification of PCAs sources. Short and medium chain polychlorinated n-alkanes (sPCAs and mPCAs) were measured in top predatory fish from nine freshwater bodies across Canada in 2010–2011. Maximum sPCA concentrations were measured in brook trout from Kejimikujik Lake in Nova Scotia (10±8ngg−1 wet weight) while the lowest concentrations were found in lake trout from Kusawa Lake in the Yukon (2±3ngg−1 wet weight). The presence of sPCAs in fish from these sites is strongly suggestive of long range atmospheric transport, given the absence of known point sources. The highest mPCA concentrations (11–12ngg−1 wet weight) were found in lake trout from Lakes Huron, Erie and Ontario. These results showed that fish from sites impacted mostly by atmospheric sources contained higher concentrations of sPCAs than mPCAs while the opposite was observed in sites impacted by industrialization. C12H20Cl6, C12H19Cl7, C14H24Cl6 and C14H23Cl7 were the most abundant homologue groups observed. Lake trout from Lake Huron showed a markedly different sPCA homologue profile, characterized by higher abundances of C11H15Cl9 and C12H17Cl9, indicating local sources. Principal components analysis of sPCA homologues abundances showed that C12H20Cl6, C12H19Cl7, C11H18Cl6, C11H17Cl7 were associated with lakes influenced by atmospheric sources while C11H16Cl8, C12H18Cl8, C11H15Cl9, C12H17Cl9 were associated with sites influenced by urban/industrial sources. Finally, concentrations of sPCAs in Lake Ontario lake trout collected in 2011 decreased 6.6-fold compared to 2001, however no significant differences were observed for mPCAs.