What is Cadmium?
Cadmium is a metal found in natural ore deposits where other elements such as zinc and copper are usually found as well. Cadmium is mostly used for electroplating other metals and for nickel cadmium batteries, pigments, coatings, stabilizers in plastics and synthetic products, and alloys. Small amounts of cadmium compounds are in television picture tubes, telephone and trolley wires, the metal in automobile radiators, control rods and shields for nuclear reactors, motor oils, and in curing agents for rubber.

How does Cadmium enter our water?
Because it is a natural element found on the earth’s crust, cadmium can leach into ground and surface waters. Major releases of cadmium can also come from human activity such as industrial waste (especially smelting and refining industries), leaching of landfills, and from the atmosphere. Cadmium can be directly released to drinking water from the corrosion of some galvanized plumbing and watermain pipe materials. Most cadmium entering surface water settles into the bottom sediments.

How does Cadmium affect human health?
Cadmium concentrations are quite low in Canada’s unpolluted freshwater and drinking water supplies. Short-term exposure above recommended levels can cause nausea, vomiting, diarrhoea, muscle cramps, salivation, sensory disturbances, liver injury, convulsions, shock and renal failure. In long-term exposures above guidelines, cadmium has the potential to cause effects such as emphysema, kidney, liver damage and softening of the bones.

How does Cadmium affect the aquatic environment?
Cadmium is toxic to freshwater fish, invertebrates, and aquatic plants and its toxicity depends on water quality parameters, such as hardness. Cadmium is most likely to settle in bottom sediments and affect bottom-dwelling aquatic life

What are the Cadmium guidelines?
To protect people from exposure to cadmium, the Federal-Provincial-Territorial Committee on Drinking Water has established a guideline of 0.005 micrograms of cadmium per litre of drinking water.

• Drinking Water Guidelines

The Canadian Water Quality Guideline for the Protection of Aquatic Life is 0.017 micrograms of cadmium per litre of water. An interim Canadian Sediment Quality Guideline, for the Protection of Aquatic Life of 0.6 micrograms per kilogram, has been developed to protect bottom dwelling aquatic life.

• Canadian Water Quality Guidelines for the Protection of Aquatic Life:
  • for water
  • for sediment

What can individuals do to help?
To prevent cadmium from reaching our water supply:

• Recycle nickel-cadmium and solar batteries.
• Be aware of product contents. Dispose carefully of old telephone wires, televisions and some resins and plastics. Select less toxic alternatives or use non-toxic substitutes wherever possible.
• Properly dispose of paints, motor oils, radiator contents, and other products containing cadmium at hazardous waste collection centres. Do not pour them down the drain or in the sewer. Pouring chemicals in these areas may disrupt septic systems or contaminate water supplies.