BEIJING (Reuters) - Chinese police detained eight executives from two companies suspected of dumping carcinogenic cadmium into a key southern China river, state media reported on Thursday, threatening drinking water supplies for millions.
Jinhe Mining Co and Jinchengjiang Hongquan Lithopone Material Co Ltd were the two most likely sources of toxic cadmium detected in the Longjiang River in the southern Guangxi region, Xinhua News Agency said late on Wednesday, citing the mayor of Hechi city.
"On behalf of the Hechi city government, I apologise to those people," Xinhua cited the mayor of Hechi as saying, adding that he had pledged to "revamp local industries and seek more sustained development."
Cadmium is used for electroplating and to make batteries and industrial paints.
Beijing has repeatedly promised to clean up pollution of waterways by toxic runoff from factories and farms -- a problem that is pervasive throughout the country. But it often fails to match rhetoric with the resources to enforce its mandates as local officials tend to put economic development ahead of environmental protection.
The mayor said the detained executives included three from Jinhe Mining Co and five from Jinchengjiang, adding that authorities were pursuing four others.
Government officials in the Guangxi region were not available for comment on Thursday.
The China Daily newspaper reported that the source of the discharge had been blocked after 20 tonnes of cadmium had flowed into the Longjiang River at Hechi on Jan 15.
Local residents rushed to buy bottled water, and many fish died despite efforts by local fire officials to dissolve the cadmium by pouring hundreds of tonnes of neutralisers into the river.
Over the next two weeks, the pollution flowed more than 100 kms (63 miles) downstream, threatening drinking water supplies in Liuzhou, a city with 1.5 million permanent residents, according to Xinhua.
The Longjiang tributary flows into the Liujiang River that eventually connects with the Pearl River Delta in neighbouring Guangdong province.
An official in the Guangxi environmental protection bureau said tap water in Liuzhou was now safe to drink, the China Daily reported. But it was not clear whether cadmium concentrations still posed a threat to downstream cities that draw their drinking water from the river.
Reporting by Sui-Lee Wee; Editing by Chris Lewis, Ken Wills and Ed Lane