Some creams promising to lighten skin, eliminate age spots and zap freckles  contain high levels of mercury, a toxic metal that can cause severe health problems, a Tribune investigation has found.

The newspaper sent 50 skin-lightening creams to a certified lab for testing, most of them bought in Chicago stores and a few ordered online. Six were found to contain amounts of mercury banned by federal law.

Of those, five had more than 6,000 parts per million – enough to potentially cause kidney damage over time, according to a medical expert.

The Food and Drug Administration banned mercury in skin-bleaching or lightening products in 1990, but the agency rarely tests the products to see if consumers are at risk. The Tribune’s tests – among only a handful ever conducted – show that tainted products are still readily available.

“I’m shocked and speechless,” said Dr. Jonith Breadon, a Chicago dermatologist  who said she sees patients weekly who ask about lightening their skin. “I just assumed since (mercury) was banned in the U.S., it never got in. But clearly that isn’t true.”

FDA spokesman Ira Allen said that with fewer than 500 inspectors reviewing imports, the agency cannot check all food, drug and cosmetic products under its jurisdiction. “It is likely that things get past us,” he said.

When notified of the Tribune’s test results, the retailers said they would pull the products from shelves, and two distributors said they would stop selling them.