Cadmium, named after the greek mythological character Cadmus, was discovered in 1817. Cadmium is highly toxic and is commonly found as impurities of zinc ores. Industrial scale production of cadmium started in the 1930s where it was initially used as an anti-corrosive coating for iron and steel.
The majority of cadmium used today is associated with the production of batteries, predominantly in the manufacture of rechargeable nickel-cadmium batteries; other uses include the production of pigments, plastic stabilisers and low melting-point alloys.
Cadmium has no known biological function in humans and is highly toxic. Along with lead and mercury, cadmium is one of six substances banned by the European Union's Restriction on Hazardous Substances and has been classified as a carcinogen to humans. Cadmium exposure is a risk factor to a large number of illnesses including kidney disease, atherosclerosis, hypertension and cardiovascular disease. The tobacco plant readily absorbs and accumulates cadmium from soil, on average the concentration of cadmium in smokers is 4 to 5 times that of non-smokers.
Cadmium occurs naturally in ores of zinc, copper, and lead and is also found in fossil fuels such as coal - the leaching of these materials can lead to the contamination of ground and surface water sources. However, the primary source of contamination of drinking water is as a result of the presence of cadmium as an impurity of zinc in galvanised pipes or from the use of solders containing cadmium in plumbing. Levels of cadmium could be higher in areas of soft water as the corrosion effect in plumbing is greater when water pH is low.
Cadmium in your drinking water can be detected by the following tests.
Cadmium can be reduced or removed from your drinking water using the following methods.
