MP16 Policy and Management
Monday, 14 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(HIG-1117-832253) An Economic and Material Flow Input-Output Model for Metals in the United States.

Higgins, C.¹, Hawkins, T.¹, Suh, S.¹, Matthews, H.¹, Goyal, A.¹, Hendrickson, C.¹, ¹ Carnegie Mellon University, Pittsburgh, 15217, USA

ABSTRACT- The continued use of toxic heavy metals in products poses risks to people and the ecosystem, and those risks can be identified using material flow analysis (MFA). In this study, heavy metal flows in the U.S. economy and environment are analyzed and their extraction, uses, pathways for exposure, and pathways for recycling are identified. An Economic Input-Output (IO) model characterizes the entire supply chain of an economy, while detailed process information of specific heavy metal-based product shows how these products penetrate the U.S. economy. The synthesis of material flow data with an economic flow model in a hybrid-unit Physical IO model, which has both monetary and mass units, allows the entire life cycle of a metal to be characterized more completely with higher resolution. A hybrid-unit Physical IO model is constructed for lead and cadmium in the U.S. in 1998. The acquisition of data and integration of the physical flows with the economic IO model is explained, as well as analysis of the resulting model. The model provides identification of the direct and indirect releases of lead and cadmium, and a mass balance of the flows of each metal. The mass balance reveals inconsistencies or data gaps that will direct further refinement of the model. Implications of the model and its results with regard to heavy metals policy and to design of recycling/recovery programs are discussed.

Key words: Material flow analysis (MFA), Hybrid-unit Physical IO analysis, Lead, Cadmium