A Princess and the Frog necklace purchased at Wal-Mart in Ohio contained high levels of the heavy metal cadmium. (Associated Press)

U.S. and Canadian product safety authorities will investigate the presence of cadmium in children's jewelry imported from China, and Wal-Mart has pulled the items from shelves after lab tests showed some were made almost entirely of the toxic metal.

The promise for action is the result of an Associated Press investigation that found some Chinese manufacturers have been substituting cadmium for lead in cheap charm bracelets and pendants being sold throughout the United States and possibly Canada.

It comes just days before the head of the U.S. Consumer Product Safety Commission is to deliver a speech to Asian manufacturers lauding them for abandoning the use of lead in children's products.

In the most contaminated piece analyzed in lab testing performed for AP, cadmium made up a startling 91 per cent of the metal content, measured by weight. The testing also showed that some items easily shed the heavy metal, raising additional concerns about the levels of exposure to children.

This Best Friends bracelet was purchased at Claire's, a jewelry chain with 3,000 stores in Canada, the U.S. and Europe. (Associated Press)

Scott Wolfson, a spokesman for the U.S. commission, said the agency would study the test results and take the necessary action. Health Canada said it is concerned and has begun an investigation.

High hazard

Cadmium is a known carcinogen. A listing by the U.S. Centers for Disease Control and Prevention ranks it No. 7 among the 275 most hazardous substances in the environment.

Like lead, cadmium can hinder brain development in the very young, according to recent research. Children don't have to swallow an item to be exposed. They can get persistent low-level doses by regularly sucking or biting jewelry with a high cadmium content.

In its investigation, The Associated Press purchased 103 items from stores in New York, Ohio, Texas and California. Lab results indicated 12 items contained at least 10 per cent cadmium.

Jewelry with the highest cadmium content came from three sources: Wal-Mart, dollar stores and the jewelry chain Claire's, which like Wal-Mart has numerous outlets in Canada.

"There's nothing positive that you can say about this metal. It's a poison," said Bruce Fowler, a cadmium specialist and toxicologist with the U.S. Centers for Disease Control.

Jewelry industry veterans in China say cadmium has been used in products there for years.

Regulations miss jewelry

A patchwork of U.S. consumer protection regulations does nothing to keep these nuggets of cadmium off store shelves. If the products were painted toys, they would face a recall. If they were industrial garbage, they could qualify as hazardous waste. But since there are no cadmium restrictions on jewelry, such items are sold legally.

Two charms on a Best Friends bracelet bought at Claire's, which has nearly 3,000 stores in Canada, the U.S. and Europe, consisted of 89 per cent and 91 per cent cadmium, respectively. Informed of the results, Claire's issued a statement pointing out that children's jewelry is not required to pass a cadmium leaching test.

"Claire's has its products tested by independent accredited third-party laboratories approved by the Consumer Product Safety Commission in compliance with the commission's standards and has passing test results for the bracelet using these standards," the statement said.

Three flip-flop bracelet charms sold at Wal-Mart contained between 84 per cent and 86 per cent cadmium. The bracelet was purchased in August 2008. The company that imported the bracelets, Florida-based Sulyn Industries, stopped selling them to Wal-Mart Corp. in November 2008, the firm's president said.

Wal-Mart has pulled the items following the report, saying the information was troubling, "and we have a responsibility to take swift action."

Sulyn president Harry Dickens said the charms were subjected to testing standards imposed by both Wal-Mart and federal regulators but were not tested for cadmium.

In separate written statements, Dickens and Wal-Mart said they consider safety a very high priority.

"We consistently seek to sell only those products that meet safety and regulatory standards," Wal-Mart said. "Currently, there is no required cadmium standard for children's jewelry."

Canada checks complaints

Health Canada said its investigation will include sampling and testing of children's jewelry for cadmium, and that it will take appropriate action once that's completed.

The agency also said it's the responsibility of companies to ensure that consumer products they import, sell or advertise meet all requirements of the Hazardous Products Act.

"Therefore, it is the responsibility of industry to test their products and take other measures as appropriate to ensure that they meet Canadian health and safety requirements," agency spokesman Gary Scott Holub said in an email.

Last month, a Health Canada report revealed that half of the children's jewelry it had tested in 2009 was made of almost pure lead, according to Canwest News, which obtained the internal report.

It said Health Canada oversaw targeted testing of 67 suspicious pieces and found 39 had illegal levels of lead. Twenty of the metallic pieces had lead levels ranging from 80 per cent to 95 per cent. These levels, comparable to lead-acid car batteries, were found in such things as an apple-shaped pendant and a key-shaped pendant with a heart, according to Canwest.

The worst offender, a plastic wristband with various metallic charms made of 95 per cent lead, was labelled lead-free, according to the report.

With files from CBC News