This toxic metal is slowly being phased out of our lives. But as presenter Justin Rowlatt discovers, while nickel-cadmium batteries may have disappeared from our gadgets, they still help to keep planes up in the air.

Chemistry professor Andrea Sella tells the story of this colourful yet poisonous element, while metals consultant Dominic Boyle says even if we stop using it all together, the stuff is still piling up.

Justin visits the offices of SES Batteries in the Indian military town of Ambala to find out why the country's army still uses nickel-cadmium batteries. And Jennifer Holdaway of the Social Science Research Council explains how cadmium found its way into China's rice supplies.

(Picture: Stack of AA nickel-cadmium batteries; Credit: Sergei Chumakov/Thinkstock)