ANN ARBOR---A University of Michigan School of Public Health study of candles purchased from stores in southeast Michigan shows that some candles on the market today are made with wicks that have either lead or lead cores that emit potentially dangerous levels of lead into the air.
The study is by Jerome Nriagu, a professor of environmental health sciences, who examined 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 for five hours.
Nriagu's study showed 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, which compares to the U.S. Environmental Protection Agency recommendation of 1.5 micrograms per cubic meter for ambient air. After one hour, five of the candles Nriagu tested emitted unsafe levels of lead into the air that measured greater than 1.5 micrograms per cubic meter.
After five hours, the lead levels in an enclosed space 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 this manner in confined spaces could pose health risks to people with weak immune systems, especially children and the elderly, Nriagu said.
"Lead poisoning remains one of the most serious environmental health diseases in this country and other parts of the world. It affects many organ systems and biochemical processes with the most serious sequelae often occurring in the central nervous, cardiovascular and blood systems," Nriagu said.