A new international population study, led by the University of Cincinnati, will be the first to examine the human developmental effects of environmental exposure to the complex metal mixture found in electronic waste (e-waste).
UC epidemiologist Aimin Chen, MD, PhD, says research on the effects of complex metal and organic pollutant mixtures in e-waste is urgently needed in order to avoid unnecessary health risks to vulnerable populations from exposure to toxic air, soil and water.
Chen and his team recently received a competitive $1.7 million National Institutes of Health grant to conduct a population-based study aimed at determining how exposure to this complex e-waste toxicant mixture impacts human health.
E-waste includes a mixture of many chemicals that cause known adverse health effects alone: lead, mercury, cadmium, chromium and polybrominated diphenyl ethers (PBDEs). Inappropriate handing of e-waste, such as burning, may produce polycyclic aromatic hydrocarbons (PAHs), dioxins and furans. It is estimated that 20 to 50 million tons of this potentially toxic trash-computers, cell phones, televisions, keyboards, printers and other electronic devices-are produced worldwide annually, much of it ending up in landfills or being improperly recycled.
UC researchers believe pregnant women-and more specifically their growing fetuses and young children-living in developing countries where primitive and informal e-waste recycling occurs are at increased risk for neurotoxicity.
"Because the brain is in a state of rapid development, the blood-brain barrier in infants and young children is not as effective as in adults, and neurotoxic substances-like heavy metals-can cause developmental damage," explains Chen.
For this new research study, UC has partnered with Shantou University in China to recruit about 600 pregnant women living in recycling and non-recycling communities in China to track neurological development of the fetus during gestation and through the first year of life. The selected recycling communities have a 15-year history of primitive, informal e-waste recycling activity. Mothers will be asked to give blood, hair and urine samples before 28 weeks of gestation and cord blood upon delivery.
Chen and his colleagues recently conducted a review to thoroughly identify toxicants found in e-waste and their potential harmful effects to brain development. The study benchmarks current knowledge of e-waste toxicant mixtures and identifies potential preventative measures to reduce human exposures. The team reports its findings and recommended actions online ahead of print on Nov. 15, 2010, in the journal Environmental Health Perspectives.
Chen says universal restrictions on disposal of e-waste do not exist. In the U.S., there are no legally enforceable federal policies to regulate e-waste-only a patchwork of legislation in about half of the states. The European Union has federal legislation restricting e-waste disposal and putting much of this responsibility on the device manufacturers.
"In countries where primitive recycling processes exist, human health-especially children's health-should drive regulation and management of recycling activities," says Chen. "Restricting the use of toxic chemicals in manufacturing electronic devices would help prevent exposures. More effective environmental regulations in e-waste management are also critically needed."
"Exposure to this type of metal mixture and persistent organic pollutants is truly unprecedented," adds Shuk-mei Ho, PhD, professor and Jacob G. Schmidlapp chair of UC's environmental health department and study collaborator. "We need a better understanding of the human health effects of mixture exposure in order to develop effective measures to protect the people who are most at risk."
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