Material Flow Analysis and Environmental Behavior of Polybrominated Diphenyl Ethers

Abstract

Recent research on material flow analysis (MFA) and atmospheric environmental behavior of polybrominated diphenyl ethers (PBDE) are reviewed in this paper. MFA studies can be classified into two categories: top-down or bottom-up types. In the top-down type, the amount of PBDE stock for each application is estimated based on trends in domestic demand for PBDE with the share of each product category. The bottom-up type builds up the flows based on concentrations in the individual final products and product flow volumes. Due to the ban on PBDE, the bottom-up type has become more important. Based on the atmospheric monitoring of PBDE, a declining trend in pentabromodiphenyl ether and octabromodiphenyl ether has been confirmed in many areas, however, due to delayed regulation on decabromodiphenyl ether, a trend of decline for this compound is still weak or as yet unconfirmed. In fact, some areas are observing a trend toward increase. As the environmental concentration decreases, non-detect data is expected to increase. It is therefore vital that appropriate analysis methods are identified, such as applying a model that can deal with censored data.