Updated

China's product safety agency will look into findings that dangerous levels of cadmium are being used in exports of children's jewelry, a Chinese official said Tuesday following growing concern in the United States about the products.

Attending a toy safety conference in Hong Kong, the official said that his agency only just learned of findings in an Associated Press investigation published Sunday and would examine the findings on cadmium contamination.

"We just heard about this, and we will investigate," said Wang Xin, a director general for the General Administration of Quality Supervision, Inspection and Quarantine.

Though Wang does not have the authority to order a full-bore inquiry, his comments were the government's first on the matter and show China's nervousness about potential troubles in the U.S., the biggest Chinese export market.

On Monday, retail giant Walmart pulled products cited in the AP report from its stores in the U.S. The attorney general of Connecticut promised to investigate suspect costume jewelry. A New York state legislator called for a ban on the sale of children's jewelry with cadmium in the state. The top U.S. consumer safety regulator warned Asian manufacturers that cadmium and other toxins must be kept out of children's charm bracelets, pendants and other baubles.

Lab tests conducted for the AP on 103 pieces of low-priced children's jewelry on sale in the U.S. found 12 items with raised levels of cadmium, which can hinder brain development in young children, according to recent research, and is known to cause cancer.

Twelve items had cadmium levels of at least 10 percent by weight. One piece had a startling 91 percent, and others contained more than 80 percent. The government has no restrictions on cadmium in jewelry.

The findings of cadmium contamination come on the heels of a string of product quality scandals in 2007 that caused Congress in 2008 to ban toys and other kids products that contain lead — another dangerous and once commonly used material. Cadmium is even more harmful.

A soft, whitish metal that occurs naturally in soil, cadmium is perhaps best known as half of rechargeable nickel-cadmium batteries, but also is used in pigments, electroplating and plastic. Low-cost jewelry makers find cadmium attractive because it is cheap and easy to work with.

Melissa Hill, a spokeswoman for Wal-Mart Stores Inc., called the AP findings "troubling." She said the company, which is the world's largest retailer, had a special responsibility "to take swift action, and we are doing so."

In taped remarks delivered at the toy safety conference in Hong Kong, the chairwoman of the U.S. Consumer Product Safety Commission urged other countries to ensure that manufacturers do not substitute cadmium, antimony or barium in place of lead in children's products.

"All of us should be committed to keeping hazardous or toxic levels of heavy metals out of ... toys and children's products," Inez Tenenbaum said in a transcript of the remarks.

Tenenbaum singled out cadmium for special vigilance and said: "Voluntary efforts will only take us so far."

The commission immediately said it was opening an investigation into the AP's findings, promising to "take action as quickly as possible to protect the safety of children."

Stung by the product scandals earlier this decade, toy manufacturers in Hong Kong said they understood why the U.S. would tighten regulations further.

Vincent Tan, the director for compliance at the Jetta Co., a toy manufacturer, said he would support a cadmium ban "if scientific evidence supports that it is leaching and causing hazards for children."

Companies like Jetta — which has made electronic and plastic toys for U.S. companies like Hasbro Inc. and Mattel Inc., but does not produce children's jewelry — do not use cadmium in paint. But the metal may be present in alloys it uses.

Children can be exposed by sucking or biting such jewelry. But without direct exposure, most people do not experience its worst effects: cancer, kidneys that leak vital protein and bones that spontaneously snap.

The worrisome results came in tests of bracelet charms sold at Walmart stores, at the jewelry chain Claire's and at a Dollar N More store. High amounts of cadmium also were detected in "The Princess and The Frog" movie-themed pendants.

U.S.-based trade groups, as well as distributors and sellers of the jewelry containing cadmium, said their products meet safety standards. Cadmium is regulated in painted toys but not in jewelry.

A cadmium specialist with the Beijing office of Asian Metal Ltd., a market research and consultancy firm, said products with cadmium are normally directed to the Chinese domestic market.

A 2008 law imposed limits on lead in children's products and sent factories rushing for substitutes. About the same time, cadmium prices dropped, in part because nickel-cadmium batteries are swiftly being replaced with newer designs.