Cadmium has featured in red traffic lights, rechargeable batteries and now has a role in quantum dots, according to Allan Blackman, from AUT, in ep 15 of Elemental.

Colourful cadmium is a favourite of artists - think cadmium yellow.

Cadmium pigments are heat resistant up to 3000 degrees celcius, and are used to paint glass. Cadmium sulphide is imperial red and has been used to make red glass for the stop light of traffic lights.

But Professor Allan Blackman from AUT tells us it is also toxic.

Go to this episode on rnz.co.nz for more details