Hirai, Y.; Fujiki, Y.; Sakai, S. (2016) 36th International Symposium on Halogenated Persistent Organic Pollutants, pp. S3.2002
The purpose of this study is to estimate the emission inventory for polychlorinated biphenyls (PCBs) in Japan from 2003 to 2013. Evaporation of PCBs from transformers and capacitors (including both in-use products and waste waiting for destruction) were estimated by multiplying the emission factors for warm and cold season with the amount of PCBs contained in those electric products. Emission of PCBs from thermal processes including cement kilns, iron ore sintering, waste incineration and other primary and secondary metal production are estimated by multiplying the activity levels of these sources and emission factors estimated by the Ministry of Environment and the Ministry of Economy, Trade and Industry for each year. The estimated evaporation of PCBs from PCB containing products (2800 kg-PCB/year in 2003) were much higher than the estimated emission of PCBs from the unintentional thermal processes (540 kg-PCB/year in 2003). For MonoCBs, however, the unintentional source (cement industry) was the dominant source (330 kg-MonoCBs/year in 2003) compared to the evaporation from PCB products (3.7 kg-MonoCBs/year in 2003). During the ten years, emission from PCB products has decreased continually (2800 kg/year in 2003 to 1100 kg/year in 2013), because the stock of PCB waste has decreased due to the PCB waste destruction and probably because the evaporation rate of PCBs from PCB products has also decreased due to the improved handling and storage of those PCB wastes. On the other hand, emission of total-PCBs from unintentional thermal processes remained rather constant (540 kg/year in 2003 and 560 kg/year in 2013). From MonoCBs to HexaCBs, the estimated emissions remained almost the same. However, from HeptaCBs to DecaCB, the estimated emissions showed a gradual decrease (4.2 kg/year in 2003 to 2.4 kg/year in 2013). These results were consistent with the result of our regression analysis on the atmospheric concentration of PCBs during these periods.