The dismantlers participating in the study worked in Guiyu, “the largest center for e-waste dismantling in China,” says coauthor Xinhui (Cindy) Bi of the Guangzhou Institute of Geochemistry, which is affiliated with the Chinese Academy of Sciences. “Every day a large amount of electrical and electronic waste [likely to contain BDE–209], such as computers, printers, mobile phones, television sets, and so on, is processed in Guiyu,” she explains. “We do not know where the waste being recycled in China originates from, but much of it is believed to come from developed countries in the West,” says Gareth Thomas of Lancaster University (U.K.), the study’s other coauthor.

BDE–209 is the main constituent of the Deca BDE formulation, which is used as a flame retardant in the plastic components of electronics products, particularly high-impact polystyrene. Deca BDE is now the only PBDE flame retardant used in North America and Europe. It has always been the primary formulation used in China.

Toxicology studies conducted with animals show that BDE–209 can impact thyroid hormones and alter brain development. Some of the newest research, presented at the Brominated Flame Retardants conference in April, shows that laboratory rats can metabolize BDE–209 to produce hydroxylated compounds that “may have very long half-lives and be very accumulative,” says Juliette Legler, a toxicologist at the Vrije Universiteit Amsterdam.

The record level of BDE–209 found in the most contaminated Chinese worker “approaches the toxic doses administered to animals in the two most sensitive neurotoxicity studies, leaving no margin of safety,” points out Sonya Lunder, a senior analyst with the Environmental Working Group, a nonprofit advocacy organization.

Heather Stapleton at Duke University’s Nicholas School of the Environment says that the workers may be metabolically debrominating BDE–209, because the amount of two other heavy PBDE compounds, BDE–207 and BDE–197, in their blood was higher than what is found in the Deca formulation. This finding is consistent with “what we’ve observed in fish when we know that they’re debrominating PBDEs,” she adds. However, Thomas points out that more research is needed to confirm this possibility. He and his colleagues did not look for hydroxylated PBDE metabolites.

One of the reasons that the Chinese workers are likely to take up such high levels of PBDEs is because “we believe that masks and gloves are rarely or never used by most of the workers involved in this industry at present,” Bi says.

The European Brominated Flame Retardant Industry Panel noted in a written statement that the ES&T research “just emphasizes the need for industrial hygiene. . . . Other monitoring programs have demonstrated that it is accepted that Deca BDE can be found in the blood of workers handling or disassembling/recycling electronic and electrical equipment but that adequate personal protective equipment minimizes levels.”

Bi says that the Chinese government now recognizes “the severe environmental pollution and potential health effects resulting from e-waste dismantling.” Although China does not yet regulate the recycling of electronics produced outside of the country, Bi says that both the National Development and Reform Commission and the Ministry of Information Industry have developed regulations that “are in the process of being issued.”

In the meantime, Bi says that she and her colleagues are planning to investigate the source of the relatively high levels of PBDEs they found in the blood of residents of Haojiang, a city 50 kilometers east of Guiyu where fishing is the main industry. Bi says they suspect that atmospheric transport is the culprit because “most of the e-waste was processed in enclosed yards with no roofs, [and] unsalvageable materials [are burned] in the open air.”