Environmental Control Challenges of Dioxins, Polychlorinated Biphenyls, and Brominated Flame Retardants
文摘
Over the past few decades, the international community has challenged on persistent organic pollutants (POPs) control issues on both global and local scale. This article deals with problems related to POPs from the standpoint of their total life cycle and examines each category of intentionally and unintentionally produced chemicals. Environmental control challenges and experiences of dioxins, polychlorinated biphenyls, and brominated flame retardants were addressed. Polychlorinated dioxins have their various release sources, but in particular, thermal processes such as waste incineration are the main emission sources. The international community has addressed this issue by adopting technologies for complete combustion and advanced emission gas treatment. With these technologies, Japan has successfully achieved more than 95% reduction of dioxin emission. PCB-containing products manufactured in the past are thought to be the main source of PCB presence now in the environment. Thermal destruction and chemical dechlorination processes have been applied for such waste PCBs. It becomes clear that brominated flame retardants (BFRs) accumulate in the environment as well as in humans. Global-scale efforts have just begun to control BFRs. From now on, we should also address the problem of brominated dioxins and try to improve the related technologies and/or develop new technologies also in the future.