Lead in Ceramic Ware

by Food and Drug Administration (FDA)

Members of a Westchester County, N.Y., family were falling ill and they couldn't figure out why. Marco Tulio Rey, 67 years old, went to see his doctor about his stomach pains. At first the doctor thought it might be stomach cancer, but was troubled by the patient's other symptoms, such as severe anemia. The doctor ordered a blood level test. When it showed an abnormally high level of lead, Rey was treated for lead poisoning. He recovered after two weeks of hospitalization.

At the same time Rey was falling ill, other members of the family felt increasing fatigue and dizziness. When Rey was diagnosed, public health officials suspected that ailing relatives might be suffering from the same malady. Tests showed that six family members had seriously high blood lead levels. Fortunately, only one required hospitalization.

While the family was recovering, a Westchester County public health worker visited the Rey home and discovered the culprit: a brown jug that a friend had purchased in Mexico and given them as a gift. The family used it to store a fermented sugar and bean drink. The public health worker could see the glaze inside the jug was corroded and the jug was lined with a powder residue that may well have contained a high lead content.

Most glazes for ceramic products contain lead but are safe because they have been properly formulated and fired to prevent the release of toxic amounts of metal into foods. However, some pottery, especially earthenware made by individuals and in small cottage industries abroad, have not been treated properly. In these pieces, acid substances may interact chemically with the glaze and accelerate the lead release. Therefore, acidic foods (such as orange, tomato and other fruit juices, tomato sauces, wines, and vinegar) stored in improperly glazed containers are potentially the most dangerous. In the 1987 case of the brown jug from Mexico, says Frederick Morrisey, a program coordinator at the Westchester County Department of Health, the acidic nature of the bean drink gradually ate away at the glaze.

Alert for Tourists

Every year, millions of Americans travel to Mexico and other countries, bringing back ceramic products for themselves and their friends. Too often, the ceramic products tourists buy from local vendors in foreign countries don't meet U.S. standards.

"What tourists bring home from Mexico is of special concern," says Edward A. Steele, acting director, executive operations staff, of the Food and Drug Administration's Center for Food Safety and Applied Nutrition. "The United States imports relatively few commercial shipments of ceramic ware from that country, yet Mexican ceramic ware increasingly is making its way across the border and into U.S. homes." Steele points out that while these pieces are often colorful, they may fall short of U.S. safety standards.

The Mexican government has been working with the United States, but so far the two countries have not been able to come up with a plan for effectively monitoring every individual who sells wares on the street.

Other countries are also of concern. During a recent trip to Spain, Steele verified his suspicion that local vendors don't always meet U.S. standards for lead-glazed products.

The problem for travelers is that there is no way to tell merely by looking at a ceramic piece whether it will leach dangerous amounts of lead. Because of his profession, Steele may be more aware of such problems than most people. So, when he traveled to Spain, he brought with him two test kits commercially available by mail order and in some drugstores around the country.

Steele says that many ceramic products he found at roadside stands and local shops would dangerously violate the American standard. For instance, Steele asked the saleswoman in the little shop next to his hotel if she knew whether the dishware she was selling could leach a dangerous amount of lead. She proudly replied that the owner had told her everything in the store was safe. However, when Steele tested a small fruit dish he purchased at the shop, he found it leached 25.5 parts per million (ppm) of lead. The U.S. legal limit for a small dish is 5 ppm.

Military personnel and others stationed abroad also are at high risk for lead poisoning. Often, says Steele, U.S. citizens who move to foreign countries will purchase an entire set of dinnerware for use. Often this dinnerware does not meet U.S. standards for lead.

Such was the case with Donald and Frances Wallace. While stationed in Italy, they bought new household items, including a pair of terra cotta coffee mugs. They each drank 8 to 10 cups of coffee a day from their mugs, and after three years it nearly killed them.

The symptoms of lead poisoning are insidious and often misdiagnosed. Mr. Wallace underwent two operations for carpal tunnel syndrome, a painful wrist disorder that he, in fact, didn't have. Mrs. Wallace's doctors thought she was suffering from porphyria, a rare, incurable metabolic disorder. Her body ached; she was dehydrated and anemic. To regain strength, Mrs. Wallace drank bouillon and juice daily from her terra cotta mug.

On his own, Mr. Wallace researched their conditions and learned that lead poisoning caused many of the symptoms that continued to weaken them. He insisted that his doctor measure their blood lead levels. The tests confirmed that the Wallaces were victims of acute lead poisoning.

FDA Inspections

Although ceramic products purchased from vendors in foreign countries remain the chief concern, FDA is looking to a quick color test developed by FDA chemists John Gould and Stephen Capar to step up inspection of imports. This test can determine — within 30 minutes — whether a ceramic product leaches excessive amounts of lead. As this article goes to press, the patent is pending for the FDA quick color test.

Steele notes that FDA is working towards putting this or a similar test "in the hands of import inspectors, who will be able to initially screen ceramic products for lead at ports of entry." Now inspectors must send all suspect pottery to the district offices for a time-consuming laboratory analysis. The test also will be made available to the general public.

FDA testing of foreign and domestic dinnerware is a cumbersome and resource-draining process. Steele acknowledges that FDA just can't check everything. (See "Pretty Poison: Lead and Ceramic Ware," in the July-August 1987 FDA Consumer.) In 1986 alone, 873 million ceramic pieces came into the United States in 46,000 shipments from 80 different countries.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.