Cadmium

Learn what you need to know about cadmium.

Also known as: Cadmium sulfate 10124-36-4, Cadmium chloride 10108-64-2, Cadmium oxide 1306-19-0, Cadmium acetate 534-090-8

What is Cadmium?

Cadmium is a metal found naturally in the earth's crust and all soils and rocks contain some cadmium. Pure cadmium is a soft, silver-white metal; however, it's unusual to find it in its pure form. It is commonly found in combination with other elements, such as oxygen (cadmium oxide) or sulphur (cadmium sulphate), or as a minor component in most zinc ores.

Where is Cadmium found?

Cadmium can enter the air through mining during the smelting process, as well as through the burning of coal or municipal waste.

Cadmium is used in industry and is a byproduct of zinc, lead, and copper refining. Industrial uses of cadmium include production of metal plating, rechargeable batteries, paint pigments, and plastics. Industrial wastewater or seepage containing cadmium can contaminate nearby ground and surface waters as cadmium moves easily through the soil.

Cadmium within contaminated soil can be taken up by mushrooms, leafy vegetables, root crops, cereals, and grains through which it enters the food chain. Cadmium can also be found in some meats, particularly liver, kidney, and shellfish.

Cadmium can be found in dust. The body does not readily release cadmium once inhaled or ingested. Exposure to low doses of cadmium over a long time can build up in the body to a toxic level.

Cadmium exposure

Cadmium cannot be absorbed through the skin, rather it enters the body through inhalation or ingestion. Inhalation is primarily a concern for people who live or work near cadmium emitting industries.

Cadmium is found in smoke from burning fossil fuels, municipal wastes, and cigarettes. Industrial facilities that process metal can create high levels of cadmium in the air and significantly increase the exposure of people living or working near them.

Tobacco plants are known to easily take up and accumulate cadmium. The use of tobacco is a significant source of cadmium exposure. People who smoke cigarettes have higher cadmium levels in their bodies than nonsmokers. There is evidence to suggest that cadmium exposure may also occur from the use of smokeless tobacco products such as chewing tobacco. Vaping fluid has been found to have cadmium in it, however very little is transferred to the person during use and is likely not a major source of exposure.

People can be exposed to cadmium when they eat plants grown in contaminated soil or when they eat fish from contaminated water. An iron deficiency can cause the body to absorb more cadmium from a person's diet. Cadmium occurs naturally at low levels in many foods. The normal intake of cadmium (1-3 micrograms per day) does not appear to cause health problems.

People can be exposed to increased amounts of cadmium by drinking contaminated water. Contamination of drinking water typically results from improper disposal of industrial chemicals.

What regulations and guidelines are available to protect people from cadmium?

No standards exist for cadmium in the air of homes. However, there are workplace limits. We use a formula to convert workplace limits to home limits; inhalation levels should be no higher than 0.0002 milligrams of cadmium per cubic meter of air (mg/m3). Levels above 0.0035 mg/m3 increase the chance of lung and kidney injury. Long-term exposure to air containing cadmium dust or fumes increases a person's lung cancer risk.

The state and federal drinking water standards are both set at 5 parts per billion of cadmium. We suggest you stop drinking water that contains more than the standard.

Health effects

The following symptoms may occur immediately or shortly after exposure to high levels of cadmium:

• Stomach irritation after ingestion of contaminated food or water.
• Lung irritation following inhalation of cadmium particles or fumes at levels greater than 300 mg/m3.

The following health effects can occur after several years of exposure to cadmium:

• Long-term, high-level exposure to cadmium have been linked to increased the risk of lung cancer in occupational settings.
• Lung disorders, including emphysema or bronchitis, can develop after long-term exposure to cadmium in air.
• Kidney damage, kidney stones, and/or more fragile bones can form as a result of eating, drinking, or breathing elevated levels of cadmium.