"The federal government should ban the use of lead weights, those fingertip-size chunks of metal that balance the tires of cars and trucks, says a petition filed with the U.S. Environmental Protection Agency last week.

While the federal government has banned lead in paint, gasoline and plumbing, among other products, the EPA has ignored an estimated 3.5 million pounds of lead weights that drop off tire rims and onto U.S. roads every year, according to a coalition of environmental groups that filed the petition.

Once the lead weights hit the road, they can be picked up by children or eaten by wildlife. They are run over by other vehicles and broken down into dust, which can be inhaled or end up in runoff that taints water and wetlands, the groups say.

Lead has been shown to cause serious neurological problems, affecting development, intelligence and behavior, particularly in children."

Jane Kay reports for the San Francisco Chronicle June 1, 2009. [2]