A metallic element that occurs most commonly in nature as the sulfide, CdS, cadmium has many important industrial applications. It is used to electroplate other metals, in the production of paints and plastics, and in nickel-cadmium batteries. The metal also escapes into the environment during the burning of coal and tobacco. Cadmium is ubiquitous in the environment, with detectable amounts present in nearly all water, air, and food samples. In high doses, cadmium is toxic. In lower doses, it may cause kidney disease, disorders of the circulatory system, weakening of bones, and, possibly, cancer.