Inexpensive jewelry coming in from overseas primarily has been found once again to contain cadmium, a heavy metal, can cause kidney, bone, lung, and liver disease. In a recent study, 69 pieces of cadmium rich jewelry were analyzed, many labeled for children and imported primarily from China, selling for less than $5 each and were purchased in 2009 and 2010.
Cadmium contamination is a global health concern. Most human exposure comes from food or tobacco grown with cadmium-rich phosphate fertilizer. Health effects typically are not acute but instead result from chronic, long-term exposure. Because cadmium can accumulate in the body, all exposures should be avoided. Agencies around the world, including the World Health Organization, are working to regulate the use and disposal of the heavy metal.
Jeffrey Weidenhamer of Ashland University in Ohio, and research leader, says:
“Our hope is that the potential hazards of cadmium laden jewelry will be taken seriously. While the bioavailability of cadmium from many items was low, the amounts of cadmium obtained from other items were extraordinarily high and clearly dangerous if these items were mouthed or swallowed by children. To think there are products on the shelf that you could pull thousands of micrograms of cadmium off by simple extractions like this is very concerning.”
Humans who put in their mouths or swallow jewelry containing cadmium may be exposed to as much as 100 times the recommended maximum exposure limit for the toxic metal. The study measured bioavailability, or how much cadmium leaked out of the jewelry. The research also found that damaged pieces of jewelry in some cases leached up to 30 times more cadmium than undamaged pieces.
In the 1950s and 1960s industrial exposure to cadmium was high, but as the toxic effects of cadmium became apparent, industrial limits on cadmium exposure have been reduced in most industrialized nations and many policy makers agree on the need to reduce exposure further.
Buildup of cadmium levels in the water, air, and soil has been occurring particularly in industrial areas. Environmental exposure to cadmium has been particularly problematic in Japan where many people have consumed rice that was grown in cadmium contaminated irrigation water. This phenomenon is known under the name Itai-Itai disease.
Food is another source of cadmium. Plants may only contain small or moderate amounts in non-industrial areas, but high levels may be found in the liver and kidneys of adult animals.
Cigarettes are also a significant source of cadmium exposure. Although there is generally less cadmium in tobacco than in food, the lungs absorb cadmium more efficiently than the stomach.
Aside from tobacco smokers, people who live near hazardous waste sites or factories that release cadmium into the air have the potential for exposure to cadmium in air. However, numerous state and federal regulations in the United States control the amount of cadmium that can be released to the air from waste sites and incinerators so that properly regulated sites are not hazardous. The general population and people living near hazardous waste sites may be exposed to cadmium in contaminated food, dust, or water from unregulated releases or accidental releases. Numerous regulations and use of pollution controls are enforced to prevent such releases.
Weidenhamer continues regarding a similar study from last year that he conducted specific to Chinese imported items:
“It was a complete surprise to find such high amounts of cadmium, up to 90% by weight, in some of these jewelry items. Given the toxicity of cadmium, information on its bioavailability was needed in order to evaluate the potential risks. That is what motivated the Environmental Health Perspectives study.”
Weidenhamer’s findings were widely reported, and after multiple recalls of children’s jewelry, the U.S. Consumer Product Safety Commission (CPSC) issued recommended limits on cadmium bioavailability. These limits were based on the amount of cadmium leached after an item soaked in a saline solution for 6 hours (to simulate putting the item in one’s mouth) or in dilute hydrochloric acid for 24 hours (to simulate ingestion).
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Written by Sy Kraft, B.A.