Facts About Cadmium

Consumers are getting a refresher course in chemistry lately, as products containing dangerous levels of various toxic elements are finding their way into children's products. First we had lead showing up in painted toys; then, antimony in Zhu Zhu hamsters; and now, cadmium in jewelry. What is cadmium, and what are its potential dangers?

Cadmium is an element, silver-white and solid at room temperature. It does not occur uncombined (on it's own) in nature. It is generally produced as a by-product of smelting zinc, ore, and copper. (Columbia Encyclopedia: Columbia University Press, 1992).

According to USGS (U S Geological Survey), approximately 51% of cadmium is produced in Asia by China, Japan and the Republic of Korea.

The metal and its compounds are highly toxic. It attacks the respiratory system, and also causes kidney problems. Fatigue, headache and vomiting can also follow constant low levels of exposure. Severe stomach and bowel problem result after swallowing.(Mosby Medical Encyclopedia: Penguin Publishing, 1992).

One of cadmium's uses is as a pigment in paints, in the form of cadmium sulfate (CdS). If you've used oils or watercolors, then you have probably heard of "cadmium yellow". Many companies substitute other non-toxic substances, and the word "hue" will be added to the color name, as in "cadmium yellow hue". (I make sure that as many of my art products as possible are non-toxic.) Ingestion of minute amounts could occur by licking the tip of a paintbrush or fingers coated with paint.

Cadmium is used in various industries to electroplate other metals to prevent corrosion. Cadmium poisoning was once generally found in industrial manufacturing situations, when workers had been exposed to it via inhalation or skin contact. Precautions and safety regulations in industry have reduced that risk.

As far as the cadmium electroplated to the jewelry, experts are concerned that the natural acids in saliva and gastric juices would release the cadmium into the bloodstream. The AP reported that it had arranged tests which included bathing suspect items in an acid solution, to gauge how much cadmium would leach out of the jewelry if swallowed.

The average home probably has cadmium, in the form of nickel-cadmium batteries (Ni-Cd). These rechargeable batteries can be found in power packs for portable tools, for example. My warranty information warns against tampering with the battery, to prevent explosions and burns, as well as possible toxicity. Our local recycler has special collections for batteries and other household hazardous materials, but that brings to mind the question; are these poisonous materials ending up in our landfills?

Our well water is tested periodically for various contaminants, one of which is cadmium. According to the site www.cadmium.org, cadmium ingestion in populations is primarily through food. The cadmium is due to natural occurrence, use of phosphate fertilizers, and sewage sludge. (Municipal sludge is, unfortunately, spread on some farm fields in our area as fertilizer.)

Another source of cadmium? Cigarette smoking. A friend of mine once gave me a list of some of the many poisons found in cigarettes and cigarette smoke. Cadmium is just one of the many trace toxins found in cigarettes (along with arsenic, formaldehyde, and other lovelies). So if you needed one more reason to quit, there you go.

It's very frustrating to the consumer when products hit store shelves, and are then found to be dangerous. Fortunately, in the case of jewelry, exposure would be limited to children putting the items in the mouth. One would hope that older children would be beyond that stage, and younger children should not have jewelry in the first place, as there is a choking hazard attached to putting such small items in the mouth.

I hate to say it, but I have taken to buying as many products as possible which are not produced in China. That takes a lot of extra time spent shopping and doing research, and sometimes it means doing without an item for a while; but as time goes by, it seems to me that the tag "Made In China" means "Beware!".

Sources: Pritchard, Justin, AP writer. "Heavy Metal Found In Jewelry". Intelligencer Journal/Lancaster New Era
11 January 2010: A1

Glanze, W. (ed.) Mosby's Medical Encyclopedia (Penguin Books, New York, 1992)

Columbia University Press, Columbia Encyclopedia, available online at www.bartleby.com

www.cadmium.org

www.metalprices.com

Special thanks to my former chemistry teacher Mr. Larry Folly. I really was paying attention in class!