“Crude e-waste recycling activities, including the open burning of e-waste, are a hot spot for PBDEs and PCDD/Fs,” says the paper’s first author, Anna Leung. The researchers found that PBDE levels in combustion residues from open burning were some of the highest found in any environmental medium (33,000–97,400 nanograms per gram [ng/g]), more than 16,000 times higher than those found in soil samples in a distant reservoir that served as a control site. High levels of PBDEs were also found in soils from an acid-leaching site (2720–4250 ng/g), where workers use a mixture of nitric acid and hydrochloric acid to recover precious metals from shredded printed circuit boards, and from a printer-roller dump site (593–2890 ng/g). BDE–209, a signature of Deca-BDE, was the dominant congener; however, signature congeners from Penta- and Octa-BDE were also found.

Levels of PCDD/Fs at an acid-leaching site were higher (12,500–89,800 picograms per gram [pg/g]) than those in the combustion residues (13,500–25,300 pg/g). Bixian Mai from the Guangzhou Institute of Geochemistry (China) suggests that “the PCDD/Fs from combustion may be emitted to the atmosphere instead of depositing to the nearby soils,” whereas the “wastes from acid leaching are directly discharged to the surrounding surfaces.”

The UN Environment Programme estimates that each year 20–50 million metric tons of e-waste are produced worldwide; this number is increasing rapidly. The U.S. EPA estimates that between 2000 and 2007, 500 million computers will become obsolete in the U.S. As an alternative to overpacking landfills or recycling domestically, some industrialized countries have found it more convenient and cheaper to export e-waste to developing countries, such as China and India, where labor costs are low, and occupational and environmental laws are lax or not well implemented.

According to the environmental group Basel Action Network, 50–80% of e-waste collected in the U.S. for recycling is exported to developing countries. “This situation is exacerbated because the U.S. has not ratified the Basel Convention, which prohibits the shipment of hazardous waste [including e-waste] across countries,” says Oladele Ogunseitan of the University of California, Irvine. “Therefore, it may not necessarily be illegal for the U.S. to export e-waste out of the country,” says Leung. She adds that China’s State Environmental Protection Administration has prohibited the import of e-waste but that the recycling of e-waste has still been largely unregulated until recently. Following in the footsteps of the EU, China is drafting ordinances to address the issue of recycling e-waste.

The interdisciplinary team, led by Minghung Wong, has been conducting research in Guiyu since 2003. Its studies provide evidence that pollutants, such as PCDD/Fs, PBDEs, PAHs, and heavy metals (Cd, Cu, Ni, Pb, and Zn), are found at higher levels at open-burning sites than at nonopen-burning sites. The work underscores the importance of e-waste processing activities.

Workers in the e-waste recycling industry are especially vulnerable. “Exposure to PBDEs and PCDD/Fs for the workers can come through industrial exposure by skin contact or inhalation,” says Minghu Zheng from the Research Center for Eco-Environmental Sciences in Beijing. The research group and Ogunseitan recommend further studies to assess the impact of pollutants on the local wildlife and human population. “We are also [undertaking] a human-health risk assessment by conducting a food consumption survey and analyzing fish tissues and human milk” for persistent organic pollutants, says Leung. She also hints that unpublished data reveal elevated levels of several heavy metals in dust inside recycling workshops and in road dust in the vicinity. She hopes that the results from their research can be used as a “case study to alert other e-waste processing regions of the adverse environmental and health impacts associated with unregulated and primitive e-waste practices.”