SAN FRANCISCO — Waste from computers, televisions and other devices used in the United States is polluting the environment and exposing workers to toxic chemicals in regions of China and India where discarded electronics are dismantled, according to a study released Wednesday.

Researchers detected high levels of toxic metals in more than 70 samples collected in March from industrial waste, river sediment, soil and groundwater around the southern Chinese city of Guiyu and the suburbs of New Delhi, according to the report by Greenpeace International. Dust from dismantling workshops contained the highest levels of contaminants.

"The extent of the contamination is even worse than we had feared. The levels analyzed are really scary and very concerning," said Ted Smith, the founder of the Silicon Valley Toxics Coalition who chairs the Computer TakeBack Campaign, which promotes responsible electronics recycling.

Most of the electronics collected in the United States for recycling are shipped to China, India and other Asian countries where worker protections and environmental safety standards are weak, Smith said.

The researchers chose to collect samples from Guiyu in China's Guangdong Province and the Mayapuri and Buradi districts of New Delhi because the two regions are known to dismantle discarded American electronics to recover valuable metals such as gold, platinum and silver.

The samples collected from those areas contained elevated levels of heavy metals used to make electronics including lead, tin, copper, cadmium and antimony. Researchers also detected the presence of polybrominated diphenyl ethers, or PBDEs, a type of flame retardant; as well as polychlorinated biphenyls, or PCBs, a class of chemicals used in insulating fluids.

The heavy metals and organic contaminants have been linked to a variety of health problems, ranging from cancer to nervous system damage.

"The high level of contamination caused by unsafe electronics disposal is a potentially serious threat to workers and to public health," said Arnold Schecter, a professor of environmental sciences at the University of Texas School of Public Health. "I think we're fooling ourselves. We think we're doing the right thing by recycling, but we're harming people in less developed countries."

Public health advocates said the study demonstrated the need to conduct larger studies of the impact of electronics recycling on the environment and people's health.

They called on U.S. lawmakers to pass legislation that would ban the export of electronic waste to developing countries and require electronics manufacturers to safely recycle their products after they become obsolete. The European Union, and several U.S. states including California, have passed similar "producer takeback" bills.

"The U.S. must step up to the plate and meet our global responsibility and stop this pollution in other parts of the world," Smith said.

Source: Associated Press