Cadmium is a soft bluish-white metal that is somewhat rare; is naturally occurring in solids and geological formations and usually found in combination with other elements such as oxygen, chlorine or sulfur. It is mainly produced as a by-product from mining, smelting and refining. Cadmium is primarily used in batteries, specifically Cd-Ni, but is also used extensively in pigments, coatings and plating and as stabilizers for plastics.
How does Cadmium get into the water?
Most of the cadmium in our water comes from the weathering of geologic formations, especially in areas with soft and acidic waters. Cadmium can also be released into the water when corrosion occurs in some galvanized plumbing and water main pipe materials. Cadmium can also come from the leaching of landfills or other industrial releases.
How is Cadmium regulated?
It is regulated by the EPA under the Safe Drinking Water Act with a Maximum Contamination Level Goal (MCLG) established at 5 parts per billion. The MCLG is the level established at which the EPA expects no health effects. The EPA sets the MCL as close to the MCLG as feasible and, in the case of cadmium, they have set the enforceable MCL at the goal of 5 parts per billion.
What health effects are associated with cadmium?
Acute health effect occur when exposed to high amounts over a short period of time. The acute effects of cadmium exposure include: stomach irritation, nausea, vomiting, salivation, cramps, diarrhea, convulsions, shock and kidney failure. Chronic effects occur when exposed to smaller amounts over longer periods of time. Chronic effects of cadmium exposure include damage to he kidney, liver, bones, and blood. Cadmium is a probable carcinogen, as there is some evidence that indicate it causes prostrate and kidney cancer in humans. Cadmium is also a probable tertogen in humans, which refers to the ability of a substance to cause birth defects by damaging the fetus.
How do you test for Cadmium?
Since Cadmium is a health-based contaminant you should have the water analyze using a laboratory.. Laboratories analyzing drinking water samples can utilize various methods including EPA method 200.7 and 200.8 which utilize an Inductively Coupled Plasma (ICP) or the Standards Method 31138 which uses Graphite Furnace.
Water Treatment Options
The EPA has approved the following treatments methods for removing cadmium from drinking water: coagulation/filtration, ion exchange, lime softening, reverse osmosis. Coagulations, filtration and lime softening are typically used in larger applications, such as public water supplies, while ion exchange and reverse osmosis can be used for residential applications.