The number of children suspected of having lead poisoning in Hunan province has skyrocketed to 1,300, up from an initial estimate of 100 the day before.
The poisonings were caused by emissions from a smelter in Wugang, media reported.
Children in other nearby villages are also being checked.
The shocking development came amid revelations that two employees of the local environmental protection bureau are being investigated for negligence.
The Wugang scare is the second case of lead poisoning this month, after more than 850 children were sickened by another smelting plant in Shaanxi province.
As of Wednesday, almost 2,000 children, all younger than 14 years of age from four villages near the Jinglian Manganese Smelting Plant in Wenping township of Wugang, had undergone tests. Of those, more than 1,350 were diagnosed as having excessive lead in their blood, a city official said yesterday.
Huang Wenbin, deputy environment chief in Wugang city, said the plant was to blame for the poisonings. It opened in May 2008 without approval of the local environment protection bureau, he said.
Two employees there are under investigation.
The plant's general manager, Liu Zhongwu, is still on the run after police detained two executives of the plant on suspicion of "causing severe environmental pollution", said an official surnamed Yang in the city's publicity department.
City government officials said it have launched an overhaul on more than 100 plants in Wugang, including seven other smelters. The government has made plans to test and compensate lead-poisoned children and their families.
In six other villages near the Jinglian plant, the local government has stepped up screening for lead poisoning. Nearly 700 blood samples were taken on Wednesday.
"Now my younger daughter is receiving treatment at a hospital in Changsha," a villager surnamed Xiao, 31, told China Daily. "But the medical tests are still underway. They're examining six children from each village near the smelter every day."
He said that 20 more children in his village who were found to have been poisoned by lead are ready for treatment.
As of yesterday, 83 cases had been confirmed by Changsha authorities. Seventeen were diagnosed as having "moderate poisoning" with blood-lead content between 250 and 499 mg per liter, 28 as "slight poison" with 200 to 249 mg and another 38 with 100 to 199 mg. The normal lead content in blood ranges from 0 to 100 mg per liter.
The 17 children with moderate poisoning have been hospitalized in Changsha and will receive free treatment, while the minor cases will be treated at home. Final test results for the other suspected cases will be released within a week.
Xinhua contributed to the story
Source: China Daily