Charlotte, N.C. ? Some jewelry your kids get from the nation’s largest retailers could cause brain damage and even wipe points from their IQ, researchers have found.

A majority of bracelets, rings, necklaces and earrings bought from big chain stores leached enough lead to cause minor neurological damage with just 20 seconds of daily contact, according to a University of North Carolina at Asheville study that will be published next month in the Bulletin of Environmental Contamination and Toxicology.

Most of the jewelry tested was aimed at children, researchers said.

One ring leached lead at 250 times the federal limit of daily exposure in children younger than 3.

Sellers are not required to disclose the content of jewelry, but at least two chains have taken steps to reduce or eliminate lead items. Some in the industry say the findings are alarmist.

Researchers say consumers have no way of telling which jewelry pieces could have dangerous lead levels. The biggest potential for high lead content is in items with a dull, antique looking finish. The pieces are sold at all types of stores, not just large chains.

UNC-Asheville researchers recommend not buying lead jewelry — typically, items not touted as being made of gold, silver or platinum — until manufacturers reduce the amount of lead.

“We hate to suggest a ban, but a lot of this jewelry is bad,” said Rick Maas, a UNC-Asheville environmental sciences professor who co-authored the study.

Excessive amounts of lead in the bloodstream can cause brain and nerve damage, particularly in small children.

This summer, the Consumer Product Safety Commission recalled 150 million pieces of toy jewelry sold in vending machines between 2002-2004 because of dangerous lead levels. Four major importers halted shipments while talking with regulators on reducing the amount of lead in jewelry. The recall stemmed from the lead poisoning of a 4-year-old from Oregon who swallowed a piece of jewelry bought in a vending machine, the CPSC said.

Focus on stores

Retailers are now the targets.

Federal regulators said they were studying lead in costume jewelry sold by mass retailers. A report is due next year.

The California Attorney General sued 13 retailers in June for failing to disclose that some jewelry sold at their stores contained lead exceeding state standards. Merchants want to remove jewelry that fails to meet legal standards and will meet with manufacturer and attorney general officials this month, said Jeff Margulies, an attorney representing eight retailers named in the suit.

Jewelry industry officials are concerned that studies like this one will unnecessarily panic shoppers.

“Too much of anything could hurt you; it’s possible you could eat too much broccoli and die from that,” said Laurie Hudson, chief executive officer of Jewelry.com, a retail Web site. “I would have a hard time believing that too much lead content in a pair of earrings or costume bracelet would destroy a life.”

UNC-Asheville researchers tested jewelry bought at 15 major retailers in California — including Wal-Mart, Target, Nordstrom and Claire’s.

Researchers wiped the jewelry pieces for 20 seconds, estimating that was an average length of time a child would fiddle with a bracelet, necklace or ring each day. More lead enters the blood stream when children put their hands in their mouths — or the pieces of jewelry.

A child’s IQ could be reduced by 2 points, Maas said, if the child were to rub jewelry that the government deems minimally hazardous for just 20 seconds a day for a month.

Among the 311 pieces of jewelry researchers tested, 54 percent contained more than 3 percent lead. Previous studies found dangerous levels of leeching in keys and plumbing parts containing as little as 1.5 percent lead.

Dull finishes worst

Researchers looked closer at jewelry with dull gray plating that gave pieces antique pewter appearance because the plating itself is made of lead. Among that select group of 62 pieces, which contained 3 percent or more of lead, almost two-thirds leeched enough lead to cause brain damage in children under 7.

But the bigger concern is that the jewelry will raise a child’s blood lead level, already bolstered by lead found in drinking water, household dust and playground soil.

“It’s a cumulative effect,” said UNC-Asheville mathematics professor Steven Patch, who co-authored the study. “There are some things you can’t control and some things you can in limiting lead exposure.”

Nordstrom began working on making all jewelry sold in the children’s department lead-free last month, a spokeswoman said.

Target said it has asked manufacturers not to use uncoated lead in jewelry. “We are surprised and disappointed to learn of the findings in the University of North Carolina report,” a company statement said.

Wal-Mart and Claire’s officials did not return calls before publication.

In addition to jewelry, high lead levels can be found in other household items — especially those made with PVC plastic. Lead dust is a byproduct of deteriorating PVC. Artificial Christmas trees — especially those about 10 years and older — can pose a health hazard from lead, the UNC-Asheville researchers said.