Twelve industrial plants in Jiangxi Province have been temporarily shut down after more than a dozen children were found with excessive lead levels in their blood, equivalent to over 100 mg per liter.

A seven-year-old boy from a village near the city of Ji'an was found with lead levels of 117 mg per liter of blood when his mother took him to see a doctor to treat pain in his throat in early June.

The consultation led the mother to conclude that pollution from a nearby industrial park in Qingyuan district of Ji'an, home to over 30 plants, may have been the source of the poisoning.

This prompted more parents in the village of Futan to have their children checked at a local hospital.

A further 15 were found to have excessive levels of lead in their blood, with the worst case seeing a staggering 299 mg per liter.

Amid fears about the effects of lead poisoning, about 100 villagers demanded that polluting enterprises be shut down.

Excessive amounts of lead in the blood can harm the nervous and reproductive systems and cause high blood pressure and anemia. In severe cases, it can lead to convulsions, comas and death.

Local authorities on Saturday ordered the temporary closure of 12 enterprises at the industrial park.

The plants are mainly involved recycling. However, none of the 30 companies at the park handle heavy metals such as lead, the city government said.

Meanwhile, tests conducted at a government hospital found only two of 205 children living near the industrial park had high concentrations of lead in their blood.

Liu Zhongkai, a deputy director of the city's health bureau, said the official testing method was more scientific and  use more advanced equipment.

Villagers can elect to undergo further tests at other hospitals if they do not trust official results, said Long Xin, a deputy governor of Qingyuan district.

Water and air samples taken from the park and the village have returned normal results.

The results of soil tests will be available in a few days, according to the statement.

Xinhua