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Historical decline and altered congener patterns of polychlorinated dibenzo‐ p ‐dioxins and dibenzofurans in fish and sediment in response to process changes at a pulp mill discharging into Jackfish Bay, Lake Superior
Author(s) -
Dahmer Shari C.,
Tetreault Gerald R.,
Hall Roland I.,
Munkittrick Kelly R.,
McMaster Mark E.,
Servos Mark R.
Publication year - 2015
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.3126
Subject(s) - congener , bay , pulp mill , environmental chemistry , contamination , sediment , bioaccumulation , benthic zone , environmental science , effluent , mercury (programming language) , polychlorinated dibenzofurans , catostomus , ecotoxicology , chemistry , fish <actinopterygii> , ecology , geology , environmental engineering , oceanography , fishery , biology , paleontology , computer science , programming language
Improved regulations for pulp and paper mill effluents and an industry shift away from elemental chlorine bleaching in the 1990s greatly reduced the release of polychlorinated dibenzo‐ p ‐dioxins and dibenzofurans (PCDD/Fs) into the environment. However, the high potential of these contaminants to persist in sediment and bioaccumulate in biota means that they have remained a concern. To document current contamination from bleached kraft pulp mill effluent, PCDD/Fs were measured in white sucker ( Catostomus commersoni ) collected from Jackfish Bay, Lake Superior. These values were contrasted to historically reported fish data as well as PCDD/F patterns from dated sediment cores. Patterns of PCDD/Fs in sediment cores from Jackfish Bay and reference sites demonstrated a relationship between contamination and mill process changes. During the peak PCDD/F contamination period (1991), when the mill was still using elemental chlorine, the contamination patterns in fish and sediment were distinct and dominated by 2,3,7,8‐tetrachlorodibenzo‐ p ‐dioxin and 2,3,7,8‐tetrachlorodibenzofuran. Following the reduction in the use of elemental chlorine during the early 1990s, a rapid decline was observed in PCDD/F contamination of fish tissue, and levels are now approaching background conditions with congener patterns more reflective of atmospheric sources. Although surface sediments from Jackfish Bay continue to have elevated PCDD/Fs, with some locations exceeding sediment quality guidelines, they do not appear to be highly bioavailable to benthic fish. Environ Toxicol Chem 2015;34:2489–2502. © 2015 SETAC