Toxic water with levels of benzene, a cancer-inducing chemical, 20 times the safe level has been recorded in China.<br /><br />Residents of Lanzhou rushed to buy bottled water after taps were turned off.<br /><br />A leak from the nearby oil company is believed to be behind the contamination, though investigations are ongoing.<br /><br />The heavily industrialised region ranks amongst the most polluted in the country.
