Chromium

The metal of modernity, spawning icons from the Chrysler Building to the Harley Davidson, this colourful element is the key ingredient in stainless steel and leather. But chromium also has a dark side - one brought to public attention by Erin Brockovich. Presenter Justin Rowlatt speaks to Erin - the real Erin - and he also travels to the Savoy Hotel in London and to the world's first steel town of Sheffield, to tell the story of chromium's biggest modern use.