Citizen buy bottled water at a supermarket in Lanzhou, capital of northwest China's Gansu Province, April 11, 2014. Tap water in downtown Lanzhou has been found to contain excessive levels of benzene, provincial authorities said on Friday. Tests carried out in the early hours of Friday showed that tap water contained 200 micrograms of benzene per liter, far exceeding the national limit of 10 micrograms per liter, according to the city's environmental protection office. (Xinhua/Guo Gang)
LANZHOU, April 11 (Xinhua) -- Excessive levels of benzene in tap water have affected more than 2.4 million people in downtown Lanzhou in northwest China's Gansu Province, provincial authorities said on Friday.
Tests at a water plant at 8:30 a.m. on Friday showed tap water contained 160 micrograms of benzene per liter, far in excess of the 10 micrograms per liter national limit, according to the city's environmental protection office.
The city government warned citizens not to drink tap water for the next 24 hours. Benzene is a colorless carcinogen used to manufacture plastics.
Tests from Thursday evening to early Friday morning found between 118 micrograms and 200 micrograms of benzene per liter at the water plant, according to Veolia Water, a Sino-French joint venture and the sole water supplier for urban Lanzhou, the provincial capital.
The levels at the plant fell to 78 micrograms of benzene per liter on Friday afternoon, according to a statement from the Gansu provincial government's information office.
Meanwhile, the tap water at some urban households was also found to contain as much as 78 micrograms of benzene per liter, according to the statement.
Veolia Water began using activated carbon at 3 a.m. on Friday to absorb the organic matter and dilute the pollution.
An initial investigation found problems in a 3 km channel that links the plant that preprocesses the water and the plant that supplies water to Lanzhou. Closure of the channel will cut the city's water supply by half, said Tian Hong, head of Lanzhou's water quality monitoring station.
Fire engines and water sprinklers will be used to carry water to affected areas.
The local government is investigating the source of the contamination, and sources with Veolia told Xinhua that they believe the benzene came from chemical waste, but refused to single out any particular plant.
They denied any possibility that the Yellow River, the original source of the water, was polluted. Gansu publicity department reaffirmed on Friday afternoon that the Yellow River, which runs through the city, is not contaminated.
Lanzhou residents panicked upon hearing the news, rushing to supermarkets or community grocery stores to stock up on bottled water.
At Hualian Supermarket, one of the largest in downtown Lanzhou, many trolleys or baskets full of cases of bottled water were seen. Latecomers gathered in front of empty shelves, waiting for resupply.
"I had no idea what benzene was, but my family are all scared. My husband called to ask me to buy as much bottled water as I can," a shopper told Xinhua.
The booking line for Lanzhou Huanghe Origin Food and Drinks Co. Ltd., the biggest barrelled water provider in the city, was busy on Friday as mounting orders came.
The company normally sells 15,000 barrels of water a day. It has already started using its 50,000 barrel reserve to meet the rising demand, said Yu Cunyuan, the company's general manager.
Chen Baohua, a professor with Lanzhou University's College of Chemistry and Chemical Engineering, warned local residents not to touch or drink the contaminated water as excessive inhalation of and contact with benzene would damage the human hematopoietic system, which is responsible for production of blood.
This is the second incident of its kind in Lanzhou in two months. On March 6, residents reported a strange odor when they turned on their taps, which was later confirmed to be a high concentration of ammonia, but still within the limits of the national standard.
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