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Updated 3:00 PM May 8, 2003



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Professor's work leads to ban on lead candle wicks

Jerome Nriagu's interest in candles began simply enough, with a visit to a local store to take a look at candle wicks.
(File photo by Bob Kalmbach, U-M Photo Services)

That initial trip led the professor of environmental health sciences to research that ultimately prompted the U.S. Consumer Product Safety Commission (CPSC) to decide in April to ban lead wicks in candles because of health risks.

"It is rare for scientists to see their work translated into policy. I'll cherish the thought for a while," Nriagu said when the ban was announced.

Nriagu characterized the decision as quick—he began his research about three years ago—and long overdue—the CPSC first got involved in the lead candle wick concern in the 1970s when it called on the industry to eliminate lead from candle wicks voluntarily. Despite that recommendation, candlemakers continued to use lead, necessitating the stronger ruling announced recently.

Candlemakers use lead in wicks because it makes the flame burn more upright, helping the candles burn longer. But after Nriagu read a research paper from Australia indicating candles made in China emitted dangerously high levels of lead when burned, he found the same thing domestically.

Nriagu measured lead emissions from 15 different brands of candles made in the United States, Mexico and China. He also examined the concentration levels of lead that lingered in the air in an enclosed space, such as a room measuring 12 feet by 12 feet and 10 feet high, after one hour and then again after five hours.

Nriagu's study found that lead emission rates for the candles ranged between 0.5 and 327 micrograms per hour. After burning the candle for one hour, the lead levels in the air of an enclosed space were estimated to range from 0.04 to 13.1 micrograms per cubic meter. The U.S. Environmental Protection Agency's standards set a limit of 1.5 micrograms per cubic meter for ambient air.

One hour later, five of the candles Nriagu tested emitted unsafe levels of lead that measured greater than 1.5 micrograms per cubic meter, and five hours later, the lead levels in enclosed spaces ranged from an estimated 0.21 to 65.3 micrograms per cubic meter. Candles produced in China and the United States released the highest levels of lead into the air.

Regular exposure to lead in confined spaces could pose health risks to susceptible people, especially children and the elderly, Nriagu says.

"I'm glad that they're getting the lead out of candles," he says of the ban, "even if it is 30 years later." He notes that in the few years since he helped draw attention to the hazards of lead candlewicks, he's seen a noticeable decline in the number of lead-wicked candles in local stores. The ban aims to get the remaining candles off the shelves as well.

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