Identification and Occurrence of Analogues of Dechlorane 604 in Lake Ontario Sediment and their Accumulation in Fish

Abstract

The dechlorane family of flame retardants, which includes Mirex (also known as Dechlorane), Dechlorane Plus (DP), and Dechloranes (Dec) 602, 603, and 604, were manufactured at a facility along the Niagara River, upstream of Lake Ontario. Some of these compounds remain in use. In a previous study, we found Mirex and Dec602 to have greater bioaccumulation potentials than Dec604 and DP based on calculated biota-sediment accumulation factors (BSAFs). In this study, analogues of Dec604, containing fewer bromines and mixed substitutions of bromine and chlorine, were identified in Lake Ontario sediment and fish using high and ultrahigh resolution mass spectrometric techniques. The tribromo-Dec604 (Br3Dec604) analogue, known as Dechlorane 604 Component B (Dec604 CB), was present in lake trout and whitefish at concentrations of 10-60 ng/g lipid weight, approximately 50-200 times greater than concentrations measured for Dec604. In addition, BrDec604 and Br2Dec604 analogues, and mixed Br2Cl2Dec604, Br3ClDec604, Br2ClDec604, and BrCl2Dec604 analogues were also present. We have shown that solutions of Dec604 and Dec604 CB exposed to UV-light undergo photodebromination and give rise to the analogues found in sediment and fish. Dec604 CB and other lesser halogenated analogues of Dec604 show greater bioaccumulation potentials than Dec604, Dec602 and DP, based on BSAFs, which highlight the need to consider likely impurities and degradation products in the assessment of persistent, bioaccumulative, and toxic compounds.

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

“…The temporal and spatial distribution of Dechloranes were generally in agreement with those of DP in the Great Lakes, indicating that the OxyChem plant in Niagara Falls was the potential emission source (Shen et al, 2011a;Sverko et al, 2010b;Yang et al, 2011). In addition, analogs of Dec 604 were recently identified in Lake Ontario sediment and fish (Jobst et al, 2013;Shen et al, 2014). These analogs contained fewer bromines and mixed substitutions of bromine and chlorine, such as tribromo-Dec 604 (Br 3 Dec 604) analog (known as Dechlorane 604 suggested a worldwide occurrence of DP related compounds and bioavailability of Dechloranes.…”

Determination of dechlorane flame retardants in soil and fish at Guiyu, an electronic waste recycling site in south China

“…The proportions of P Dec 602 þ Dec 603 to DP in the fish samples were 2.5%e67%, while only 0.063%e4.2% in soil, indicating that Dec 602 and Dec 603 may have greater bioaccumulation and/or bioavailability potential than DP. It was also reported for the lake trout and sediments in Lake Ontario that Dec 602 and Dec 603 had higher biota-sediment accumulation factor (BSAF) compared to syn-DP and anti-DP isomers (Shen et al, 2014).…”

“…Recently, degradation products of Dec 602 and Dec 604 were also found in Great Lakes fish and arctic Beluga whales (Shen et al, 2012(Shen et al, , 2014, but information on photodegradation of Dec 602, Dec 603, and Dec 604 is limited. To better understand environmental fate of these dechlorane series compounds, the photolytic degradation experiments were conducted by exposing Dec 602, Dec 603, Dec 604 CB and Dec 604 standard solutions to UV light for 80 min, as well as syn-and anti-DP for comparison purpose.…”

“…Therefore, Dec 604 might have decomposed to less brominated products during e-waste recycling operations such as open-burning and acid treatment although the degradation pathway might be different from that of direct photolysis. A recent study showed that Dec 604 analogs were present in sediments and fish in the Great Lake (Shen et al, 2014), suggesting that further studies on degradation products of Dec 604 in e-waste areas should be considered.…”

“…DP concentrations in dust samples from the ewaste area were found to be greatly higher than those from rural areas and urban areas, and strong positive correlations were observed between human hair and dust samples (Zheng et al, 2010). In addition to DP, Dechlorane 602 (Dec 602), Dechlorane 603 (Dec 603) and Dechlorane 604 (Dec 604) might be also used as flame retardants , and these dechlorane series compounds were found to have high bioaccumulation potential compared to DP (Shen et al, 2014). In this study, we investigate the presence of the dechlorane compounds in farmland soil collected around a number of e-waste recycling sites in Guiyu because environmental occurrence of these dechlorane flame retardants have not been reported in e-waste recycling areas except for DP.…”