Local governments in Hunan Province that had been unwilling to clamp down on polluters previously, will now likely pay the price after a string of lead poisoning cases. Like many other parents of the lead-poisoned children, Lei Guo refuses to be appeased although doctors tell him his two children are getting better.

"Why are they feeling no less pain if their blood lead levels have dropped?" he says.

The 30-year-old migrant worker hurried home from Guangzhou March 16, when he heard the news of lead poisoning in his hometown, a village in Guiyang County of Chenzhou City, central China's Hunan Province.

Blood tests showed the amount of lead in his two-year-old son's blood and four-year-old daughter's stood at 474 micrograms per liter and 418 micrograms per liter, respectively, much higher than the normal level of below 100.

Results of tests at two medical institutions in Chenzhou City over the past week showed that 191 of 423 children from Guiyang County had excessive blood lead levels, among which forty-six had lead levels high enough to be classified as lead poisoning, said Chenzhou Health Bureau in a statement.

Excessive amount of lead in the blood can cause damage to the digestive, nervous, and reproductive systems and cause stomachaches, anemia and convulsions.

Sources of pollution

Three lead smelters held accountable for discharging contamination, which caused the poisoning, have been closed, says Zhang Jiyao, deputy director of Chenzhou Municipal Environmental Protection Bureau.

Zhang says none of the three companies have gone through environmental assessment, and the bureau is still assessing the ground water, soil and the smelters' waste discharge to collect more proof.

Lei says the Yuanshan Lead Recycling Company, one of the three closed smelters, is the one that sickened his children.

The company, which produced two tonnes of lead every day was less than 300 meters from the village. Villagers say the black smoke of the company killed crops and gave them sore throats.

The lead poisoning cases in Guiyang emerged about 10 months after 254 children were found with excessive levels of lead in their blood in the neighboring Jiahe County of Chenzhou in July last year.