Perspective on polychlorinated dibenzo-p-dioxin and dibenzofuran emissions during chemical production in China: an overlooked source of contemporary relevance.

Polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/DFs) are pollutants of significant global concern, and China with its large size and industries is one of the main dioxin-emitting countries in the world. PCDDs/DFs may be formed during the manufacture of chemicals and can either remain in the products as impurities or be emitted into the environment or residues disposed to landfills. The uncertainties in the environmental emissions of PCDDs/DFs from the chemical production industry in China are large because of the complex nature of the industry and variability in the technologies used and limited monitoring conducted. In the current study, we used the PCDD/DF emission factor from the updated United Nations Environment Programme (UNEP) toolkit 2013, information from otherwise published data, and the chemical production data in 2010 to estimate PCDD/DF emissions from the chemical productions in China. Based on these data, it was estimated that there is 1480 g toxic equivalent (TEQ) from the chemical production industry in China, which is much higher than the value that was estimated and used in the national implementation plans (NIPs) for China (102.4 g TEQ in 2004). These results indicate that current PCDD/DF emissions from the chemical production industry in China may be overlooked. Therefore, we suggest that attention should be paid to PCDD/DF emissions from the chemical production industry in future updates of the Chinese NIP and that appropriate measures to decrease PCDD/DF emissions should be taken by better monitoring of products and processes in chemical production industry.