Cadmium

Friedrich Stromeyer found cadmium in 1817 as an impurity in zinc carbonate, and cadmium sulfide and selenide soon gave painters cadmium yellow, orange and red — intense, opaque and lightfast, and used heavily by Monet, Van Gogh and Matisse. The element is seriously toxic and accumulates in the kidneys and bones. From the 1910s the Kamioka mines discharged cadmium into the Jinzu river in Toyama prefecture; it concentrated in irrigated rice paddies, and villagers developed such severe osteomalacia that their bones fractured under their own weight, a condition named itai-itai, ouch-ouch disease, and recognised as one of Japan's four great pollution diseases. Nickel-cadmium cells were once ubiquitous and are now restricted under RoHS, though cadmium survives in CdTe thin-film solar panels and in reactor control rods.