An environmental protection official was challenged to swim in a highly polluted river with 200,000 yuan (US$32,040) as a reward if he did.

In response, the official has pledged to build facilities to combat the pollution and to control population in the area.

A river is seriously polluted by large amount of floating garbage in Rui'an, Wenzhou, east China's Zhejiang Province. [Chinanews.com]

Jin Zengmin, chairman of a glasses company in Hangzhou, asked Bao Zhenming, director of the environmental protection bureau in his hometown of Rui'an in Wenzhou City, to swim in a local river for just 20 minutes. Jin claimed pollution had caused cancers among many villagers living nearby.

He posted the challenge on his microblog at the weekend to raise awareness of the problem.

Jin claimed that shoe-making workshops along the river were discharging industrial sewage direct into the river as well as toxic gas into the air.

Seventeen residents among the 1,000 villagers died of cancer last year, Jin said.

Jin posted pictures showing lots of rubbish floating in the river and the water in parts of it turning white. He said he and his friends often swam in the river when they were young and when there were no workshops.

Bao phoned Jin on Sunday, saying it was his responsibility and promising to treat the river soon, Jin said.

Yesterday, Bao said: "The river has truly been polluted, but mainly by household garbage rather than industrial waste."

He denied that the cancer cases were related to the workshops because officials had found no industrial waste being discharged.

The pollution was mainly caused by an overexpansion of the migrant population in the area, he said. Some 40,000 citizens and 80,000 out-of-towners were living in the neighborhood, far exceeding the numbers the region could cope with.

He said many workers in about 100 labor-intensive workshops along the river were discharging household waste into the river.

Bao said officials would be clearing the waste on and along the river soon.

"The city government has built a garbage recycling plant and will put it into use this year. A new sewage treatment plant will also be built within three years," Bao said.

Jin Xiaokun, a neighborhood official, said illegal residential buildings along the river would be dismantled to control the migrant population.