Search

There has been ever-increasing international interest in investigating the long-term emissions of chemicals in products (CiPs) throughout their entire life cycle in the anthroposphere. Hexabromocyclododecane (HBCDD) is a contemporary example of special interest due to the recent listing of this hazardous flame retardant in the Stockholm Convention and the consequent need for parties to take appropriate measures to eliminate this compound. Here, we conducted a scenario-based dynamic substance flow analysis, coupled with interval linear programming, to forecast the future HBCDD emissions in China in order to assist with the implementation of the Stockholm Convention in this current world's predominant HBCDD manufacturing and consuming country. Our results indicate that, under a business-as-usual scenario, the cumulative HBCDD production will amount to 238,000 tonnes before its phase-out, 79% of which will be consumed in domestic market, accumulate as stocks in flame-retarded polystyrene insulation boards, and ultimately end up in demolition waste. While the production is scheduled to end in ca. 2021, emissions of HBCDD would continue until after 2100. For the entire simulation period 2000–2100, 44% of total cumulative emissions will arise from the industrial manufacture of HBCDD-associated end-products, whereas 49% will come from the end-of-life disposals of HBCDD-containing waste. The most effective end-of-life disposal option for minimizing emissions we found was, a pre-demolition screening combined with complete incineration. Our study warns of the huge challenges that China would face in its eliminating HBCDD contamination in the following decades, and provides an effective methodology for a wider range of countries to recognize and tackle their long-term emission problems of hazardous CiPs. Keywords: Hexabromocyclododecane, Emissions, Chemicals in products, Dynamic substance flow analysis, Interval linear programming, End-of-life

Health risk assessment (HRA) has been recognized as a useful tool for identifying health risks of human activities. In particular, this method has been well applied to spatially defined units, such as a production plant, a treatment facility, and a contaminated site. However, the management strategies based on the risk information will be more efficient if the comprehensive picture of total risks from all kinds of sources is depicted. In principle, the total risks can be obtained when all risk sources are assessed individually. Apparently, this approach demands huge amount of efforts. This study develops a methodology that combines substance flow and risk estimation to facilitate examination of risk in a systemic way and provide comprehensive understanding of risk generation and distribution corresponding to flows of substances in the anthroposphere and the environment. Substance flow analysis (SFA) and HRA method is integrated to produce a systemic risk assessment method, from which substance management schemes can be derived. In this study, the chromium cycle in Taiwan is used as an example to demonstrate the method, by which the associated substance flow in the economy and the risk caused by the substance in the environmental system is determined. The concentrations of pollutants in the environmental media, the resultant risks and hazard quotients are calculated with the widely-used CalTOX multimedia model. Keywords: Health risk assessment, Substance flow analysis, Systemic, Chromium, CalTOX