Polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) and monobromo-polychlorinated dibenzo-p-dioxins/dibenzofurans (MoBPXDD/Fs) in the atmosphere and bulk deposition in Kyoto, Japan

Polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) and monobromo-polychlorinated dibenzo-p-dioxins/dibenzofurans (MoBPXDD/Fs) in atmosphere, bulk atmospheric deposition and soil in Kyoto, which is an urban city in Japan, were measured. Decabromodiphenyl ether (D10BDE, BDE-209) was detected in relatively high concentrations compared to other PBDE congeners in most samples. Similar results, in which D10BDE was predominantly detected, were reported in other studies in Japan. However, these homologue profiles differ from those of studies conducted in North America. The partitioning of semivolatile organic compounds between atmospheric gas phase and particulate-associated phase is an important factor in their environmental behavior. In this study, atmospheric particulate phase fraction (fP) of the brominated compounds increased with increasing bromine number, and fP was higher in samples collected in winter than in those collected in summer. Moreover, fP of PBDFs and MoBPXDFs was higher than that of PCDFs with the same halogen number. These results agree well with expectations from the vapor pressure of the brominated compounds and PCDD/Fs. Among the brominated compounds in the atmosphere, the level of MoBPXDD/Fs correlates positively with that of PCDD/Fs. This relationship has been previously observed in waste incineration samples. These results suggest that one of the sources of MoBPXDD/Fs in the atmosphere is incineration byproduct. The level of PBDD/Fs seems to correlate positively with that of PBDEs. This relationship suggest that the PBDD/Fs in the atmosphere relate to PBDEs, which is an impurity of PBDE products, or formed by the manufacture or combustion of plastics containing PBDEs.