Photodegradation of decabromodiphenyl ether in house dust by natural sunlight
Photodegradation of decabromodiphenyl ether in house dust by natural sunlight
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DOI：
10.1897/07-301r.1
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发表时间：
2008-02-01
影响因子：
4.1
通讯作者：
Dodder, Nathan G.
中科院分区：
文献类型：
--
作者：
Stapleton, Heather M.;Dodder, Nathan G.
在溶剂/水混合物、沉积物和土壤等几种基质中观察到十溴二苯醚（BDE 209）的光解降解;但是，没有研究调查BDE 209在室内灰尘中的降解潜力。在本研究中，将天然粉尘材料和掺有BDE 209的粉尘材料暴露在阳光下，累计时间为200小时。在两种基质中均观察到BDE 209的降解，但与天然粉尘材料相比，掺加粉尘中的BDE 209降解率高35%。假一级降解速率分别为2.3 × 10（-3）和1.7 × 10（-3）/小时。在200小时的接触过程中，多达38%的BDE 209原始质量在加标灰尘中降解，其中25%无法解释，并以未知的途径和/或产物消失。剩余的13%是由溴化程度较低的同系物形成的。在加标粉尘中检测到的脱溴产品包括所有三种非溴同系物（BDE 206、BDE 207和BDE 208）和几种八溴同系物（BDE 196、BDE 197、BDE 201、BDE 202和BDE 203/200）。在八溴二苯醚商用混合物中，BDE 201是一种非常小的成分（低于检测限，为0.8%），BDE 202未被检测到。因此，室内灰尘中存在这些同系物可能是BDE 209环境脱溴的标志。BDE 197与BDE 201的比例也可能表明BDE 209的降解。因为在本研究的两种接触情景中，这两种同系物的比例似乎都达到了一个稳态值（类似于1）。
Photolytic degradation of decabromodiphenyl ether (BDE 209) has been observed in several matrices such as solvent/ water mixtures, sediments, and soil; however, no studies have investigated the degradation potential of BDE 209 in house dust. In the present study, both a natural and a BDE 209-spiked dust material were exposed to sunlight for 200 cumulative h. Degradation of BDE 209 was observed in both matrices but was 35% greater in the spiked dust relative to the natural dust material. The pseudo-first-order degradation rates were 2.3 X 10(-3) and 1.7 X 10(-3) per hour for the spiked and natural dust, respectively. During the 200-h exposure, as much as 38% of the original BDE 209 mass was degraded in the spiked dust, 25% of which could not be accounted for and was lost to unknown pathways and/or products. The remaining 13% was accounted for by the formation of lower brominated congeners. Debrominated products detected in the spiked dust included all three nonabrominated congeners (BDE 206, BDE 207, and BDE 208) and several octabrominated congeners (BDE 196, BDE 197, BDE 201, BDE 202, and BDE 203/200). In technical commercial octa-BDE mixtures, BDE 201 is a very small component (below detection limit to 0.8%), and BDE 202 is not detected. Therefore, the presence of these congeners in house dust may provide a marker of environmental debromination of BDE 209. The ratio of BDE 197 to BDE 201 may also be indicative of BDE 209 degradation. as the ratio of these two congeners appeared to reach a steady-state value (similar to 1) in both exposure scenarios in the present study.