Los Angeles ? Federal and state watchdogs opened a new front Monday in the campaign to keep poisons out of Chinese imports, launching inquiries into high levels of cadmium in children’s jewelry while Walmart pulled many suspect items from its store shelves.

A day after The Associated Press documented the contamination in an investigative report, the top U.S. consumer safety regulator warned Asian manufacturers not to substitute other toxins for lead in children’s charm bracelets and pendants.

Regulators and lawmakers reacted swiftly to the AP report, which found that some Chinese manufacturers have been using cadmium, sometimes at extraordinarily high levels. Congress clamped down on lead in those products in 2008, but cadmium is even more harmful.

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.”

Members of Congress voiced anger about the imports. Sen. Bill Nelson, a Florida Democrat, said he’s reviewing the law that regulates such substances to decide if a fix is needed.

“Parents will be outraged to learn certain jewelry makers overseas thought they could pull a fast one at the expense of our kids’ safety,” said Democratic Sen. Mark Pryor of Arkansas, who has championed stronger rules for children’s products.

Cadmium, which is known to cause cancer, is a soft, whitish metal that occurs naturally in soil. It’s perhaps best known as half of rechargeable nickel-cadmium batteries, but also is used in pigments, electroplating and plastic.

Cadmium is attractive to Chinese manufacturers because it is cheap and easy to work with. But, like lead, it can hinder brain development in the very young, recent research shows.

In taped remarks to be delivered today 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 remarks to an international toy safety conference.

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.”

Lab tests were conducted for the AP on 103 pieces of low-price children’s jewelry such as charm bracelets and pendants purchased around the country. Virtually all were imported from China.

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 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.

Eighty-nine items were free of cadmium.