Lead Contamination of Food
Lead is a naturally occurring bluish-gray metal found in small amounts in the earth. It has no special taste or smell and can be found in all parts of our environment (3). Human activities such as mining, manufacturing, and the burning of fossil fuels are the major sources of environmental lead (3). It has many different uses, most importantly in the production of batteries, but also in ammunition, metal products (solder and pipes), roofing, and devices to shield x-rays (3). Because of health concerns, lead from gasoline, paints and ceramic products, caulking, and pipe solder has been dramatically reduced in recent years (3). The major sources of lead in drinking water are lead plumbing, soil carried into water by rain and wind, and wastewater from industries that use lead (1). Food can contain lead if lead-containing dust gets onto crops while they are growing or during food processing (1). Lead can also get into food through food containers.
Although really dangerous pieces of china, ones you should not use for food or drink at all because of high lead risk, are fairly rare, and lead is no longer used on pottery dishes, lead has been used for centuries in food containers. It has been used both for the bright colors on ceramic dishes and for the smooth, transparent glaze (2). Some older pieces of china may contain lead which can leach out from the surface of the dish and get into foods and beverages. Then, when the food is eaten, the lead gets into the body. The amount of lead that leaches from a dish depends on how the dish is used and what kind of food is put in it (2). For example, acid foods and drinks will leach lead out of dishes much faster than non-acid foods. Spaghetti sauce, salsa, soy sauce, orange juice, applesauce, coffee, tea, cola drinks, and salad dressing are examples of acid foods. If you aren't sure about the lead in your dishes, you should not use them for storing food. The longer the food stays in contact with a dish surface that contains lead, the more lead will be leached into the food. Heating up food in a lead-containing dish can speed up the lead-leaching process. A combination of these factors will make the problem even worse. An example would be storing spaghetti in a lead-containing ceramic dish and then heating it in the microwave (2).
Lead is one of the most studied metals and much information has been accumulated on it's toxicity. It has been shown to cause neurological disorders, reproductive problems, diminished intelligence and a host of other ills. The major exposure of lead to the general population in food is through fruits and grains, according to the Agency for Toxic Substances and Disease Registry, part of the U.S. Public Health Service. Lead in the food chain comes mostly from direct deposit from the air to plants and from livestock eating soil laced with lead as they eat the plants. The bans on leaded gasoline and paint have reduced exposure (3).
Precautions that can be taken to reduce your exposure to lead in food include, avoiding the use of glazed pottery and pewter dishes to serve or store food, avoiding the storage of beverages in leaded glass decanters, keeping the home clean and as dust free as possible, eating a variety of foods, and eating foods rich in calcium, iron and Vitamin C so your body will absorb less lead from specific food sources that have been exposed to lead (2).
Here are some very informative external links that pertain to Lead in food:
1. Diane Corrin. Identifying Lead in Your Home. Minnesota Extension Service, University of Minnesota.1994. URL: http://www.mes.umn.edu/Documents/B/D/BD658.html
2. California Tableware Education and Enforcement Program. URL: http://www.dnai.com/~cteep/index.html
3. ToxFAQs. Lead. Agency for Toxic Substances and Disease Registry. April 1993. URL: http://atsdr1.atsdr.cdc.gov:8080/tfacts13.html
This Page prepared by B.T. Johnson, December 1997 UCD EXTOXNET FAQ Team.