Materials flow analysis of e-waste: Domestic flows and exports of used computers from the United States

The management of electronic waste (e-waste) presents new sustainability challenges, prominent among these is informal electronic recycling in the developing world fed by both international and domestic sources. There is a need to mitigate environmental impacts of informal recycling while maintaining social and economic benefits of refurbishment and reuse. The development of appropriate social responses is hindered by critical data gaps, which include lack of data on trade flows of used and scrap electronics, flows invisible to trade statistics of many countries. We address this data gap by proposing and implementing an approach to quantify the exportation of used and scrap equipment from a particular country or region to the rest of the world. The approach is based on material flow analysis and combines collection of primary survey data from residential and business/public sectors with secondary data from available recycling, landfill and computer adoption studies. Exports are estimated through materials balance: exports = generated - reuse - recycling - landfill. The proposed methodology is implemented in a case study of desktop (excluding monitors) and laptop computers in the United States (US) in 2010. Results indicate that 40 million used and scrap computers entered the end-of-life management sector, from which 30% were reused domestically, 6-29% were exported, 17-21% were landfilled in domestic sites and 20-47% were collected for domestic recycling in 2010. The range in results reflects uncertainty arising from inferring end-of-life fate from individual and institutional users. Given sufficient resources to conduct a survey, the proposed materials flow analysis method can be widely applied to other devices and nations.