From discount stores to luxury retailers, investigators continue to find lead in jewelry.

The latest tests by the Center for Environmental Health found lead in jewelry from 10 retailers in California, many of which are stores for teens: The Buckle, Charlotte Russe, Claire's, Cost Plus, DD's Discount, Express, Forever 21, Saks Fifth Avenue, Styles for Less and Wet Seal.

The tests on items from Express, Saks, Styles for Less and Wet Seal were done for the California Attorney General's Office, which has notified the retailers they're in violation of state law.

Lead, unlike other controversial chemicals like bisphenol A, is a clear health threat, and has been for some time. And researchers continue to find out the dangers it poses.

Two recent studies, both published in the National Institute of Environmental Health Sciences's peer-reviewed journal Environmental Health Perspectives, demonstrated the impacts that lead exposure during pregnancy can have on a woman's unborn child.

One study, investigating children's IQ scores in relation to their mother's blood lead level, concluded that lead exposure during pregnancy could have "lasting and possibly permanent effects" on a child's IQ. The second study showed that lead exposure during the first trimester (three month period), when some women are not even aware that they are pregnant, had the most pronounced effects on a child's mental development.

The Center for Environmental Health has been testing jewelry since 2003, and its work with the California Attorney General helped create a settlement in 2006 with 71 companies, forming standards for eliminating lead-tainted jewelry that bred the current state law.

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