Children's jewelry is sold at a wholesale market in Yiwu, China. Interviews with more than a dozen manufacturers and sellers confirm cadmium is a common ingredient in the trinkets. ((Associated Press))

Young children should not be given any cheap metal jewelry imported from China because it could contain high levels of cadmium, the head of the U.S. Consumer Product Safety Commission says.

"We have proof that lead in children’s jewelry is dangerous and was pervasive in the marketplace. To prevent young children from possibly being exposed to lead, cadmium or any other hazardous heavy metal, take the jewelry away," CPSC head Inez Tenenbaum posted Wednesday evening on the regulator's website.

Her comments follow an investigation by The Associated Press that revealed some cheap jewelry imported from China and sold at major North American chains like Wal-Mart and Claire's were almost entirely made of cadmium, a heavy metal that is more toxic than lead.

In the AP investigation, 103 pieces of low-priced children's jewelry were tested for cadmium. Twelve were found to contain at least 10 per cent of the toxic metal, including several with content as high as 90 per cent.

In other tests that were part of the AP investigation, several of those shed very high amounts of the metal when analyzed for how much of the toxin a child might be exposed to after swallowing the item.

"Because of these recent developments, I have a message for parents, grandparents and caregivers: Do not allow young children to be given or to play with cheap metal jewelry, especially when they are unsupervised," Tenenbaum wrote.

Cadmium replacing lead

Observers have noted that the use of cadmium in children's jewelry comes as new U.S. regulations have severely restricted lead levels in such trinkets.

"We are moving swiftly to stop the replacement of lead with cadmium and other hazardous heavy metals in children’s products imported from China," wrote Tenenbaum.

U.S. regulators were moved to action after the March 2006 death of a four-year-old Minneapolis boy, who died four days after he swallowed a metal charm that was nearly pure lead.

Since 2004, the CPSC has conducted more than 50 recalls of more than 180 million units of metal jewelry because it contained a hazardous amount of lead. And since August 2009, it has been illegal to produce a piece of children’s metal jewelry with more than 300 parts per million of lead.

"Now we hear about cadmium in jewelry. This is unacceptable," wrote Tenenbaum.

Health Canada is in the process of conducting a routine round of testing on children's jewelry to determine cadmium levels.

In 2009, Health Canada tested 41 pieces of children’s jewelry for lead and cadmium, but it has refused CBC News requests to release the cadmium results.

With files from The Associated Press