Tire-balancing weights getting the lead out

The little lead weights clipped on the outer rim of your vehicle's wheels may be the biggest source of lead put into the environment each year, and they may soon be on their way out.

The Environmental Protection Agency Friday will recognize a group of tire retailers (including Wal-Mart and Costco), government-related entities (including the Postal Service and Air Force) and auto manufacturers that have agreed to phase out lead wheel weights by 2011.

The little gray weights about the size of a pinky finger are used to balance the wheels so they don't vibrate when they rotate and so tires don't wear improperly.

They can fall off wheels, however, and get crunched into dust — floating into the air and washing into the groundwater. Lead is a neurotoxin, meaning it attacks the nervous system. It can cause brain damage and is most harmful to children under 6.

Lead weights already are banned in the European Union and in some Asian countries, where larger steel or zinc alloy weights are used.

Lead weights haven't been identified as the cause of any specific case of pollution poisoning by the EPA, but the element is dangerous enough that getting it off the roads is important, said Susan Bodine, assistant administrator for the agency's office of solid waste and emergency response.

"We know a lot about exposure to lead, and we know what the exposure pathways are," Bodine said. "The fact that we have these huge percentages of the whole distribution chain signing up (to phase out lead wheel weights) is a tremendous gain, and 2011 is not that far off."

The EPA estimates that 13% of wheel weights fall off annually, crunching under the weight of other vehicles and washing into sewers or entering landfills after streets are cleaned. The average 2.5-ounce weights could add up to 2,000 tons of lead into the environment a year, according to the U.S. Geological Survey.

The voluntary program is an acknowledgment by many of the companies that this is an issue they can no longer avoid, said Jeff Gearhart, campaign director of The Ecology Center, an environmental policy group.

"There was a lot of foot-dragging by some of the companies," Gearhart said. "This year, it's become more and more clear that the writing is on the wall. … It's not a question of if, it's a question of when."