Researchers from University of California, Berkeley's School of Public Health have found lead, cadmium, chromium, aluminum and five other metals in common lipstick brands. Researchers said that the level of metals in the products were high enough to cause a serious health complication.

Metals have been detected in cosmetics before, and heavy metals in lipstick and lip gloss are especially a cause for concern, as they often get ingested by the wearer. According to estimates, a lipstick user might ingest 24 milligrams of lipstick/lip gloss per day, while some who reapply repeatedly eat up to 87 milligrams a day.

"Just finding these metals isn't the issue; it's the levels that matter. Some of the toxic metals are occurring at levels that could possibly have an effect in the long term," said S. Katharine Hammond, professor of environmental health sciences and lead investigator of the study.

The study included 32 different lipsticks and lip glosses. The study results showed that a user who consumed an average amount of lip makeup would have a high exposure to chromium, which is associated with stomach cancer, although most studies link cancers from chromium exposure to lung cancer in people exposed to it at an occupational setting.

Also, overexposure to manganese for a long time has been linked to damage to the nervous system. However, lead levels in 24 products were below acceptable levels.

Researchers said that the there is no reason why people should avoid using these products, but added that health regulators need to be aware of the level of metals in some of these products. Currently, there are no U.S. standards for metal level in cosmetic products.

"I believe that the FDA (Food and Drug Administration) should pay attention to this. Our study was small, using lip products that had been identified by young Asian women in Oakland, Calif. But, the lipsticks and lip glosses in our study are common brands available in stores everywhere. Based upon our findings, a larger, more thorough survey of lip products and cosmetics in general is warranted," said Sa Liu, a UC Berkeley researcher in environmental health sciences and lead author of the study, according to a news release.

The study is published in the journal Environmental Health Perspectives.