More than 2.4 million people in downtown Lanzhou, northwest China's Gansu Province, have been affected by tap water found to contain excessive levels of benzene, provincial authorities said on Friday. Tests carried out in the early hours of Friday showed that local tap water contained 200 micrograms of benzene per liter, far exceeding the national limit of 10 micrograms per liter, Xinhua quoted to the city's environmental protection office as saying. The city government warned citizens not to drink tap water in the next 24 hours. On Thursday, tests found that the water contained 118 micrograms of benzene per liter, according to Veolia Water, a Sino-French joint venture and the sole water supplier for the urban areas of Lanzhou, the provincial capital. Benzene is a colorless chemical which is often used to make plastics. Excessive benzene can increase the risk of cancer. The local government is investigating the source of the contamination. The departments of health and environmental protection were ordered to take more samples for examination and to monitor the pollution respectively.
