Debromination of the Flame Retardant Decabromodiphenyl Ether by Juvenile Carp (Cyprinus carpio) following Dietary Exposure

Abstract

The congener 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE 209) is the primary component in a commonly used flame retardant known as decaBDE. This flame retardant constitutes approximately 80% of the world market demand for polybrominated diphenyl ethers (PBDEs). Because this compound is very hydrophobic (log K(ow) approximately 10), it has been suggested that BDE 209 has very low bioavailability, although debromination to more bioavailable metabolites has also been suggested to occur in fish tissues. In the present study, juvenile carp were exposed to BDE 209 amended food on a daily basis for 60 days, followed by a 40-day depuration period in which the fate of BDE 209 was monitored in whole fish and liver tissues separately. No net accumulation of BDE 209 was observed throughout the experiment despite an exposure concentration of 940 ng/day/fish. However, seven apparent debrominated products of BDE 209 accumulated in whole fish and liver tissues over the exposure period. These debrominated metabolites of BDE 209 were identified as penta- to octaBDEs using both GC/ECNI-MS and GC/HRMS. Using estimation methods for relative retention times of phenyl substitution patterns, we have identified possible structures for the hexa- and heptabromodiphenyl ethers identified in the carp tissues. Although exposure of carp to BDE 209 did not result in the accumulation of BDE 209 in carp tissues, our results indicate evidence of limited BDE 209 bioavailability from food in the form of lower brominated metabolites.

Sorption of PBDE in low‐density polyethylene film: Implications for bioavailability of BDE‐209

“…This relative difference ranges from 0 to 70% at 60 d with an average of 30 AE 24%, falls below 20% for all but one congener (BDE-181, with a relative difference of 37%) at 240 d, and diminishes at 365 d (the relative difference for BDE-181 stands at 22%) (Table S4). Clearly, a calibration time of 60 d, a time duration often used in fish exposure experiments [5][6][7], can yield reasonable accuracy when C w is determined with the laboratory-calibrated C pe /C w . We previously obtained a curvilinear relationship between the logarithm of PDMS-water partition coefficient (log K f ) and log K OW for PCBs with the turning point at log K OW approximately equal to 7 to 7.5 [17,18], which is similar to the fieldobserved correlations between log-based bioconcentration factor and log K OW [19][20][21].…”

“…Limited data on dietary uptake of PBDEs have been acquired through laboratory studies [5][6][7][8][9]23] and are summarized in Table S4. For northern pike (Esox lucius), dietary uptake efficiency decreases singly from BDE-47 (92 AE 20%) to BDE-99 (62 AE 10%) and to BDE-153 (40 AE 10%) [23] with increasing log K OW (Table 1).…”

“…Previous studies have demonstrated that the net dietary uptake efficiency (parallel to bioavailability) of BDE-209 in common carp (Cyprinus carpio) was much lower than those for BDE-28, -47, -99, -153, and -183 [5][6][7]. Two independent studies [8,9] also reported low dietary uptake of BDE-209 in rainbow trout (Oncorhynchus mykiss).…”

PBDE exposure from food in Ireland: optimising data exploitation in probabilistic exposure modelling

“…Hence, and although the dose range for BDE-209 is clearly smaller than for BDE-99 or -47 in this study, BDE-209 may be relevant for human health. There is increasing evidence that BDE-209, which is contained in decaBDE, is persistent, bioaccumulative, and might be debrominated to lowerbrominated BDEs (Stapleton et al, 2004;He et al, 2006;Kierkegaard et al, 2007;Van den Steen et al, 2007;Schenker et al, 2008). In addition, the scientific discussion about toxic effects of BDE-209 is ongoing (Viberg et al, 2003;Van der Ven et al, 2008).…”

PBBs, PBDEs, and PCBs levels in hair of residents around e-waste disassembly sites in Zhejiang Province, China, and their potential sources

“…High levels (mean = 192.38 ng g − 1 dw, n = 6) of PBDE209 were also found in all of the soil samples collected from the four disassembly sites (Table 2). PBDE209 can be degraded easily through exposure to light (e.g., UV radiation, direct sunlight) and through biological activity in the environment, with a short half-life in days (Hagmar et al, 2000;Stapleton et al, 2004). Therefore, it is possible that PBDE209 was sporadically being released from the e-waste into the soil in the vicinity.…”