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. (15th October 2015)

• Record Type: Journal Article
• Authors: Dahmer, Shari C.; Tetreault, Gerald R.; Hall, Roland I.; Munkittrick, Kelly R.; McMaster, Mark E.; Servos, Mark R.
• Is Part Of: Environmental toxicology and chemistry. Volume 34:Number 11(2015:Nov.)
• Page Start: 2489
• Page End: 2502
• Publication Date: 2015-10-15
• Subjects: Pollution -- Environmental aspects -- Periodicals; Environmental chemistry -- Periodicals; 615.902
• DOI: 10.1002/etc.3126
• Languages: English
• ISSNs: 0730-7268

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <sec id="etc3126-sec-0001" sec-type="section"> <p>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‐<italic>p</italic>‐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 (<italic>Catostomus commersoni</italic>) 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‐<italic>p</italic>‐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. <italic>Environ Toxicol Chem</italic> 2015;34:2489–2502. © 2015 SETAC</p> </sec> </abstract>