BE: MUSES: Tracking Heavy Metal Life Cycle Pathways with Input-Output Methods

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

This Biocomplexity in the Environment - Materials Use: Science, Engineering and Society research project is aimed at developing input-output models of heavy metal flows throughout some 500 economic sectors in the United States, including those representing product use and recycling. This next generation of models will build upon the existing Economic Input-Output Life-Cycle Assessment (EIO-LCA) model, providing a basis for the materials use studies of metals such as cadmium, chromium, copper, lead, mercury and nickel. The heavy metals are of considerable concern as they are in widespread use in numerous industries and many are quite toxic. Understanding how and why we use these toxic materials can help the decision-makers make use of them more effectively or reduce/eliminate their use altogether. This research will result in an inexpensive, quick analysis tool for both existing material flows and changes in material flows. Emissions estimates will be corroborated using independent information sources for emissions and ambient concentrations, and these will be combined to assess and characterize the uncertainty in model predictions. International comparisons of metals use, reuse and recycle rates in Canada and Japan will provide insights into the magnitude of problems and possible material management strategies. These next generation LCA models will permit steady-state supply chain, releases, uses and recycling flows of heavy metals to be identified at the individual product level up through the industrial sector level. The models will also provide estimates of changes in heavy metal flows due to new technologies, growth in economic activity and changes in mix of economic activity. Scenarios leading to long-term sustainable materials use will be identified involving both new technologies and management strategies. With comparison to multiple datasets and simulation results, the data and model uncertainty will be identified and characterized. The project will implement the models on the Internet for widespread use, including education modules and a specialized interface intended for middle and secondary school students. The new models will inform the various stakeholders such as industry, environmental groups, regulators and the public at large who are concerned with these heavy metal flows.