cadmium contamination(The release and presence in the air, water and soil of cadmium, a toxic, metallic element, from sources such as the burning of coal and tobacco and improper disposal of cadmium-containing waste)
calcium(A malleable silvery-white metallic element of the alkaline hearth group; the fifth most abundant element in the earth crust, occurring especially as forms of calcium carbonate. It is an essential constituent of bones and teeth and is used as a deoxidizer in steel)