Brominated and chlorinated flame retardants in Lake Ontario, Canada, lake trout (Salvelinus namaycush) between 1979 and 2004 and possible influences of food-web changes

Abstract

Concentrations of non-polybrominated diphenyl ether (PBDE) brominated (hexabromocyclododecane [HBCD], 1,2-bis[2,4,6-tribromophenoxy]ethane [BTBPE], and pentabromoethylbenzene [PEB]) and chlorinated (Dechlorane Plus [DP] as well as short- and medium-chain chlorinated paraffins [SCCP and MCCP, respectively]) flame retardants were evaluated in archived Lake Ontario, Canada, lake trout (Salvelinus namaycush) samples collected between 1979 and 2004. Polybrominated diphenyl ethers also were analyzed to provide a point of reference for comparison to previous studies. Concentrations of the dominant PBDE congeners (BDEs 28, 47, 99, 100, 153, and 154) increased significantly from 1979 until the mid-1990s, then either leveled off or decreased significantly between 1998 and 2004, a result that corresponds to those of previous studies. In contrast, BDE 209 increased approximately fourfold between 1998 and 2004. The temporal trends of the non-PBDE flame retardants varied, with sum (sigma) HBCD and DP showing significant overall decreases; BTBPE, sigmaSCCP, and sigmaMCCP showing parabolic trends; and PEB showing no overall change during the study period. Because many of the non-PBDE chemicals may be used as replacements for penta- and octa-BDE mixtures, these results will provide a baseline to evaluate future usage patterns. Possible changes in food-web structure, evaluated through stable nitrogen isotopes (delta15N), may be influencing our interpretations of contaminant trends in lake trout and are hypothesized to be partially responsible for the observed decrease in concentrations of BDEs 28, 47, 99, 100, 153, and 154 between 1998 and 2004. Retrospective analyses evaluating temporal trends in stable isotope values at the base of the food web, however, are recommended to test this hypothesis further.

Sources and environmental behaviors of Dechlorane Plus and related compounds — A review

“…SE and PLE (including ASE) were applied to solid samples, while LLE and SPE (e.g., C18) were used for liquid sample extraction . Mixed organic solvents, such as n-hexane/ acetone (v/v: 1/1) (Hoh et al, 2006;Ismail et al, 2009;Peverly et al, 2015;Ren et al, 2008;Salamova et al, 2014;Zhang et al, 2011a, b), n-hexane/dichloromethane (v/v: 1/1) (De la Möller et al, 2010Möller et al, , 2011Zhang et al, 2013), and the same mixtures with different proportions (Kang et al, 2010;Tomy et al, 2008;Wu et al, 2010;Xian et al, 2011), were commonly used for extraction.…”

“…Cleanup or purification of the environmental sample extracts could be done by a silica gel column (Hoh et al, 2006;Ismail et al, 2009;Ren et al, 2008;Salamova et al, 2014) or a multilayer column packed with acidic and basic silica gel Kang et al, 2010;Liu et al, 2014;Wu et al, 2010;Zhang et al, 2013) except for sediment. It was also reported that alumina and Florisil columns, as well as commercial SPE column (i.e., Oasis® HLB) were effective (Cequier et al, 2015;Zhang et al, 2011b;Zheng et al, 2015a).…”

“…It was also found to be persistent in suspended sediment (half-life: approximately 17 years, Sverko et al, 2008) and fish (half-life: 14 years, Ismail et al, 2009). It has been observed in the Arctic regions and marine environment, indicating its long-range atmospheric transport (LRAT) potential (Möller et al, 2010(Möller et al, , 2012a.…”

Particle-bound Dechlorane Plus and polybrominated diphenyl ethers in ambient air around Shanghai, China

“…Recent research has shown that some halogenated flame retardants are potentially toxic, bio-accumulative, ubiquitous and persistent in the environment (Ismail et al, 2009;Muir and Howard, 2006), especially polybrominated diphenyl ethers (PBDEs) (de Wit, 2002;Law et al, 2003Law et al, , 2006Law et al, , 2008Talsness, 2008). Penta-and octa-BDEs were regulated in Europe and the Unites States (Hites, 2004) and were added as new persistent organic pollutants (POPs) to the Stockholm Convention at the 4th Conference of the Parties (COP-4) held in May 2009 (www.pops.int).…”

“…It was only recently detected in the environment (Hoh et al, 2006) even though it has been produced for almost fifty years. Most published research on DP has focused on the Great Lakes area (Hoh et al, 2006;Qiu et al, 2007;Qiu and Hites, 2008;Sverko et al, 2008Sverko et al, , 2010Tomy et al, 2007), which results suggest that DP is bio-available and bio-accumulative (Gauthier and Letcher, 2009;Ismail et al, 2009). As for Asia, Qiu and Hites (2008) analyzed the tree barks from China and Korea and suggested that there might be Asia-specific sources of DP to the environment.…”