Tracking the Global Generation and Exports of e‑Waste. Do Existing Estimates Add up?

The transport of discarded electronic and electrical appliances (e-waste) to developing regions has received considerable attention, but it is difficult to assess the significance of this issue without a quantitative understanding of the amounts involved. The main objective of this study is to track the global transport of e-wastes by compiling and constraining existing estimates of the amount of e-waste generated domestically in each country <i>M</i>_GEN, exported from countries belonging to the Organization for Economic Cooperation and Development (OECD) <i>M</i>_EXP, and imported in countries outside of the OECD <i>M</i>_IMP. Reference year is 2005 and all estimates are given with an uncertainty range. Estimates of <i>M</i>_GEN obtained by apportioning a global total of ∼35,000 kt (range 20,000–50,000 kt) based on a nation’s gross domestic product agree well with independent estimates of <i>M</i>_GEN for individual countries. Import estimates <i>M</i>_IMP to the countries believed to be the major recipients of e-waste exports from the OECD globally (China, India, and five West African countries) suggests that ∼5,000 kt (3,600 kt–7,300 kt) may have been imported annually to these non-OECD countries alone, which represents ∼23% (17%–34%) of the amounts of e-waste generated domestically within the OECD. <i>M</i>_EXP for each OECD country is then estimated by applying this fraction of 23% to its <i>M</i>_GEN. By allocating each country’s <i>M</i>_GEN, <i>M</i>_IMP, <i>M</i>_EXP and <i>M</i>_NET = <i>M</i>_GEN + <i>M</i>_IMP – <i>M</i>_EXP, we can map the global generation and flows of e-waste from OECD to non-OECD countries. While significant uncertainties remain, we note that estimated import into seven non-OECD countries alone are often at the higher end of estimates of exports from OECD countries