Polybrominated diphenyl ethers PBDEs degradation

The structural range of industrially important representatives of these groups is enormous, and includes chlorobenzenes (solvents), to PCBs (hydraulic and insulating fluids), and polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDE) ethers (flame retardants). There is widespread concern over both the persistence and the potential toxicity of all these compounds, so that sites contaminated during their production represent a threat both to the environment and to human health. Comments have already been made in Chapter 6, Section 6.5.1.1 on the pathways for the aerobic bacterial degradation of chlorobenzenes and chlorobiphenyls. 

See AC Gerecke, PC Hartmann, NV Heeb, et al. 2005. Anaerobic Degradation of Decabromodiphenyl Ether. Environmental Science and Technology 39 1078-1083 and J He, KR Robrock and L Alvarez-Cohen. 2006. Microbial Reductive Debromination of Polybrominated Diphenyl Ethers (PBDEs). Environmental Science and Technology AQ-AA29-AA3A. 

The HO -initiated oxidation of 2,4,4 -tribromodiphenyl ether (BDE-28) in the atmosphere and in water solution has been studied and found to occur more readily in the former, especially at the less-brominated Ph ring. The hydrox-ylated dibrominated diphenyl ethers (HO -PBDEs, PBDE = polybrominated diphenyl ethers) are formed through direct bromine-substitution reactions or secondary reactions of HO adducts. Polybrominated dibenzo-p-dioxins resulting from o-HO -PBDEs are favoured products compared with polybrominated dibenzofurans generated by bromophenols and their radicals. The complete degradation of HO adducts in the presence of O2/NO, which generates unsaturated ketones and aldehydes, is less feasible compared with the H-abstraction pathways by 03." ... 

One of the main concerns with plastic resin pellets is that they carry persistent organic pollutants (POPs). POPs are human-made chemicals used in a variety of anthropogenic activities, including industry, agriculture and daily life. POPs include polychlorinated biphenyls (PCBs), different sorts of organochloiine pesticides (e.g. DDTs and HCHs) and brominated flame retardants (polybrominated diphenyl ethers, or PBDEs). Because of their very slow rate of degradation, POPs are persistent in the environment. POPs are... 

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