Cadmium is a toxic heavy metal which has been used for a variety of industrial applications for many centuries. The metal is present in many everyday items such as batteries and electroplating processes.
The use of cadmium has been heavily regulated by both national and international organizations, such as the US Environmental Protection Agency (EPA) and the European Union, due to its carcinogenic and chronic toxic effects. For example, the Occupational Safety and Health Administration (OSHA) has put in place numerous regulations limiting workplace exposure.
Cadmium is a natural element found in small amounts in rocks, soil, water, and vegetation. Many products, such as fertilizers and batteries, contain manufactured cadmium. Its most important use is in rechargeable nickel-cadmium (Ni-Cd) batteries.
Cadmium exposure to humans typically occurs through the inhalation of dust and fumes, the ingestion of certain foods, or from smoking. It is often found in significant concentrations in tobacco, shellfish, and other seafood.
Cadmium is also found in some paints, galvanized steel, aluminum, brass, and bronze. Brass and bronze can contain up to 8% cadmium, and aluminum products can contain up to 9%. It is also used for electroplating, in the manufacture of fluorescent and smokeless powders, and in the production of some pigments.
Cadmium can accumulate in both soil and water. In the environment, cadmium combines with other compounds and forms insoluble salts which tend to settle out of water. They may be re-suspended and carried away in water currents.
Cadmium and its compounds are toxic to humans, mammals, and birds, even in small amounts. Chronic exposure to cadmium can damage the kidneys and lung tissue, as well as cause bone defects, osteoporosis, and anemia.
Acute exposure to cadmium, especially by inhalation, can cause pneumonia, kidney and liver failure, and even death. Infants and children are particularly vulnerable to cadmium toxicity. Animal studies have shown that prenatal exposure to cadmium can cause reproductive and developmental toxicity in the offspring.
The concentration of cadmium in the environment can be reduced by controlling its use, proper waste disposal, and recycling. Regulations that control the content of cadmium in products and the disposal of cadmium wastes are also of great importance.
Cadmium is an integral part of our lives, and its careful use and management is essential for protecting human and environmental health. As a society, it is our responsibility to understand the potential risks associated with cadmium exposures, and to take necessary steps to reduce them.
