Legacy Polybrominated Diphenyl Ethers (PBDEs) Trends in Top Predator Fish of the Laurentian Great Lakes (GL) from 1979 to 2016: Will Concentrations Continue to Decrease?

Abstract

Polybrominated diphenyl ethers (PBDEs) were widely used as fire retardants and have been detected throughout the Great Lakes (GL) ecosystem. The concentration trends (after fish age normalization) of PBDEs in top predator fish (lake trout and walleye) of the GLs were determined from 1979 to 2016, which includes most of the period when PBDEs were manufactured and used in this region. The fish samples were collected by two national (U.S. and Canada) long-term monitoring and surveillance programs. Trends in total concentrations (age-normalized) of the five major PBDE congeners (BDE-47, 99, 100, 153, and 154) found in fish across all five lakes have varied over time. Significant increases were observed from 1990 to 2000 (16.3% per year). Rapidly decreasing concentrations (−19.5% per year) were found from 2000 to 2007. Since 2007, the decreasing trend has become smaller (less than −5.5% per year) and relatively unchanged from 2011 to 2015. BDE-47, the congener with the highest concentrations in lake trout, has decreased continuously (ranging from −6.7% to −16.2% per year) in all lakes except Lake Erie. This decrease can be associated with the voluntary and regulatory phase out of production and/or usage of PBDEs since 2000. However, it has been offset by recent (since 2007) increasing trends of the other four higher brominated BDE congeners, especially BDE-100 and 154. Production and usage of commercial penta- and octa- BDE mixtures containing primarily the five major PBDE congeners was discontinued in 2004 in the U.S.A. and 2008 in Canada. These results indicate increasing fish uptake and bioaccumulation of higher brominated BDE congeners may be related to the transformation of BDE-209 to lower brominated BDE compounds in the GL environment or food web. Considering the abundance of BDE-209 in existing products and sediment in GL region, the duration of the unchanging total PBDE concentration trend in GL fish could be longer than expected.

Patterns and Trends of Polybrominated Diphenyl Ethers in Bald Eagle Nestlings in Minnesota and Wisconsin, USA

“…In addition to ∑PBDEs, we compared 5 congeners (BDE‐47, ‐99, ‐100, ‐153, and ‐154) that generally have the highest concentrations in aquatic biota (Route et al 2014a; Zhou et al 2019). To estimate study area means, we fit a parametric survival mixed effect model (frailty model; Govindarajulu et al 2011) using the function survreg in package survival for each analyte (Spears and Isanhart 2014).…”

“…Bald eagle nestlings from all study areas had congener profiles that were typical for top-level predators of Midwestern large rivers (Blocksom et al 2010) and the Great Lakes (Gauthier et al 2008;Pérez-Fuentetaja et al 2015;Gandhi et al 2017;Su et al 2017;Zhou et al 2019), although there was substantial variation. We found BDE-47 to be consistently highest, followed by BDEs-99 and -100, whereas BDE-153 and -154 contributed much less across all 12 study areas (Table 1).…”

“…The PBDE burden in piscivorous fish and birds of the Midwestern United States is dominated by 5 congeners associated with penta‐BDE formulations, BDE‐47, ‐99, ‐100, ‐153, and ‐154 (Blocksom et al 2010; Gandhi et al 2017; Zhou et al 2019), although other congeners are found. The exact ratio of PBDE congeners depends in part on the source, but can also vary by species (Gandhi et al 2017; Su et al 2017).…”

Characterization of a Sequential UV Photolysis-Biodegradation Process for Treatment of Decabrominated Diphenyl Ethers in Sorbent/Water Systems

“…The percentage contribution of BDE-209 to the total PBDE contamination in soil has often been reported to be greater than 60% and may exceed 90%. For example, one detailed investigation of sediments from the Laurentian Great Lakes (GL) showed that BDE-209 was the dominant congener, accounting for more than 90% of the total mass of the five major PBDE congeners present [2]. The accumulated BDE-209 in GL sediments has adversely impacted the GL ecosystem; this is an ongoing problem since BDE-209 is still present in many commercial/industrial products.…”

“…Such a system avoided the need to dewater, and allowed for the optimal mixing and control of redox conditions. Importantly, this type of system is ubiquitous in aquatic ecosystems (e.g., wetlands, river/lake/ocean sediments, water reservoirs) and agricultural farms (e.g., paddy field, aquafarm), which are common sinks for the accumulation of POPs/EDCs [ 1 , 2 ]. Moreover, soil slurry reactors (SSRs) are central to many important ad-situ or ex-situ remediation technologies [ 8 ].…”