LED light bulbs are becoming increasingly popular with designers and consumers of green technology, as they use less electricity, last longer, and emit more light on a pound-for-pound basis than traditional incandescent bulbs. However, while it may be tempting to look at them as having solved the problem of environmentally-unfriendly lighting, researchers from the University of California would advise against such thinking.

Scientists from UC Irvine and UC Davis pulverized multicolored LED Christmas lights, traffic signal lights, and automobile head and brake lights, allowed residue to leach from them, and then analyzed its chemical content. They discovered that low-intensity red LEDs contained up to eight times the amount of lead allowed under California law, although generally brighter bulbs tended to contain the most contaminants. While white bulbs had a lower lead content than their colored counterparts, they still had high levels of nickel.

Besides the lead and nickel, the bulbs and their associated parts were also found to contain arsenic, copper, and other metals that have been linked to different cancers, neurological damage, kidney disease, hypertension, skin rashes and other illnesses in humans, and to ecological damage in waterways. UC Irvine’s Oladele Ogunseitan said that while breaking a single bulb and breathing its fumes would not automatically cause cancer, it could be the tipping point for an individual regularly exposed to another carcinogen.

The study found that the production, use and disposal of LEDs all present health risks, which the public should be made aware of. It suggests that a special broom, gloves and mask should be used when cleaning up broken bulbs, and that crews attending to car accidents or broken traffic lights should be required to wear protective gear, and treat the material as hazardous waste.

LEDs are currently not classified as toxic, and are disposed of in conventional landfills.

Ogunseitan blames the situation on a lack of proper product testing before LEDs were presented as a more efficient replacement for incandescent bulbs – which are now being phased out around the world. Although a law requiring more stringent testing for such products was scheduled to begin on January 1st in California, it was opposed by industry groups, and Governor Arnold Schwarzenegger put it on hold before leaving office.

“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,” said Ogunseitan. “And it's a preventable risk.”

Incandescent bulbs, incidentally, contain very high levels of lead and mercury, while compact fluorescents are also high in mercury.

The UC Irvine and UC Davis team's study appears in the January 2011 issue of Environmental Science & Technology.