Cadmium is a heavy metal of major environmental and health concern. It occurs naturally in the earth's crust. The highest concentration of cadmium in nature is found in sedimentary rock. Sedimentary rock formations are associated with the formation of underground water supplies. Cadmium is used in various industrial activities.
Cadmium does not corrode easily, so it works well in batteries (its primary use), manufacturing of alloys, pigments. Also used as a coating for steel and copper, as an additive in plastics and in solar panels. Cadmium can leach into ground water from landfills, illegal dumping and industrial manufacturing processes. Cadmium can also leach into drinking water from galvanized pipes.
Potential for Human Exposure
Exposure to cadmium includes cigarette smoke, eating foods high in cadmium and contaminated drinking water.
Cadmium in Food
Cadmium occurs naturally in many foods because it is present in the soil and water. Cadmium levels in most U.S. foods are between 2 and 40 parts per billion (2-40ppb). Fruits and beverages contain the least amount of cadmium, while leafy vegetables and raw potatoes grown in contaminated soils with high levels of cadmium contain the most. Shellfish, liver, and kidney meats are also high in cadmium.
It's estimated that of the 30 micrograms (mcg -- millionths of a gram) of cadmium the average person ingests daily, 1-3 mcg is retained by the body.
Cadmium in Cigarette Smoke
A single cigarette typically contains 1-2 mcg of cadmium. When burned, cadmium is present at a level of 1,000-3,000 ppb in the smoke. Approximately 40 to 60 percent of the cadmium inhaled from cigarette smoke is able to pass through the lungs and into the body. This means that for each pack of cigarettes smoked, a person can absorb an additional 1-3 mcg of cadmium over what is taken in from other sources in their daily life.
Smokers typically have twice as much cadmium in their bodies as non-smokers.
The U.S. Environmental Protection Agency (EPA) suggests that a safe level of cadmium in drinking water is 5 ppb or less. The EPA believes that this level of exposure to cadmium will not produce any of the health problems associated with cadmium.
Cadmium causes kidney, blood, and bone damage in humans and numerous effects in laboratory animals including liver necrosis, kidney damage, decreased bone calcium, peripheral neuropathy, testicular damage, and impaired neurobehavioral development. Cadmium compounds are classified as human carcinogens by several regulatory agencies. The International Agency for Research on Cancer and the U.S. National Toxicology Program have concluded that there is adequate evidence that cadmium is a human carcinogen. General non-cancer symptoms of acute exposure include:
- Renal failure
- Muscle cramps
- Liver damage
Protecting against Cadmium
The best way to protect against cadmium exposure is to avoid sources of cadmium. Since cadmium can enter the water supply naturally or through man-made activities it is important to test your water sources.
The Health Metric heavy metals test is easy to use and will alert you to heavy metal contamination in your home or workplace water supply. If heavy metals are detected you have the option of filtering your water with a reverse osmosis filtration system or buying bottled water. Be sure to test your water filter to make sure it is functioning properly.