2018 Volume 29 Issue 6 Pages 470-481
Brominated dioxins such as polybrominated dibenzo-p-dioxins (PBDDs), polybrominated dibenzofurans (PBDFs), and coplanar polybrominated biphenyls (Co-PBBs) are considered to have toxicity profiles (toxic, persistent and bioaccumulation) similar to those of the chlorinated analogues which have been prohibited as persistent organic pollutants (POPs) under the Stockholm Convention on POPs. Therefore, a joint World Health Organization (WHO) and United Nations Environment Programme (UNEP) expert panel has recommended the use of WHO toxicity equivalency factor for risk management of brominated dioxins. The Ministry of the Environment Japan (MOEJ) continues to investigate its actual emission of brominated dioxins such as PBDD/Fs. These have a close relationship with the lifecycle of decaboromodiphenyl ether (decaBDE), especially through manufacturing, recycling and incinerating. This is because PBDD/Fs are well known to be an impurity contained in decaBDE and in unintentionally generated compounds through photo and thermal degradation of brominated flame retardants (BFRs), including decaBDE. Since 2017, decaBDE has been listed in the Stockholm Convention and marked for elimination. Because of this, emission changes for brominated dioxins resulting from the shift to alternatives for decaBDE should be investigated from now on. As the WHO and UNEP expert panel pointed out, toxicity studies with brominated dioxins in fish and mammalian models are also needed for their appropriate risk management.
