11 February 2011

University of California reports on toxic metals in LEDs

“Light-emitting diodes are touted as the next generation of lighting. But as we try to find better products that do not deplete energy resources or contribute to global warming, we have to be vigilant about the toxicity hazards of those marketed as replacements,” says Oladele Ogunseitan, chair of the Department of Population Health & Disease Prevention at University of California Irvine (Lim et al ‘Potential Environmental Impacts of Light-Emitting Diodes (LEDs): Metallic Resources, Toxicity, and Hazardous Waste Classification’, Environmental Science & Technology, 2011; 45 (1): 320).

LEDs marketed as safe, environmentally preferable alternatives to traditional lightbulbs contain lead, arsenic and a dozen other potentially hazardous substances, according to the researchers.

Ogunseitan and fellow scientists at UCI and University of California Davis crunched, leached and measured multicolored lightbulbs sold in Christmas strands; red, yellow and green traffic lights; and automobile headlights and brake lights. They found that low-intensity red lights contained up to eight times the amount of lead allowed under California law but, in general, high-intensity, brighter bulbs had more contaminants than lower-intensity ones. White bulbs contained the least lead, but had high levels of nickel.

“We find the low-intensity red LEDs exhibit significant cancer and noncancer potentials due to the high content of arsenic and lead,” the research team says about the holiday lights. Results from the larger lighting products will be published later, but according to Ogunseitan, “it’s more of the same”.

Lead, arsenic and many metals in the bulbs or their related parts have been linked in hundreds of studies to different cancers, neurological damage, kidney disease, hypertension, skin rashes and other illnesses, say the researchers. The copper used in some LEDs also poses an ecological threat to fish, rivers and lakes.

Ogunseitan says that breaking a single light and breathing fumes would not automatically cause cancer, but could be a tipping point on top of chronic exposure to another carcinogen.

Risks are present in all parts of the lights and at every stage during production, use and disposal, the study found. When bulbs break at home, residents should sweep them up with a special broom while wearing gloves and a mask, Ogunseitan advises, and crews dispatched to clean up car crashes or broken traffic fixtures should don protective gear and handle the material as hazardous waste. Currently, LEDs are not classified as toxic and are disposed of in regular landfills. Ogunseitan has forwarded the study results to California and federal health regulators.

He cites LEDs as an example of the need to mandate product replacement testing. LEDs are hailed as being safer than compact fluorescent bulbs, which contain dangerous mercury. But Ogunseitan says that LEDs have not been properly tested for potential environmental health impacts before being marketed as the preferred alternative to inefficient incandescent bulbs (which are now being phased out under California law). A long-planned state regulation originally set to take effect on 1 January would have required advance testing of such replacement products. However, it was opposed by industry groups, a less stringent version was substituted, and Governor Arnold Schwarzenegger placed the law on hold days before he left office.

“The work continues,” says Ogunseitan, a member of the state Department of Toxic Substances Control’s Green Ribbon Science Panel. He reckons that manufacturers of LEDs and other items could easily reduce chemical concentrations or redesign them with truly safer materials. “Every day we don’t have a law that says you cannot replace an unsafe product with another unsafe product, we’re putting people’s lives at risk,” he concludes.

Tags: LEDs

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