The re-examination of 23 children suspected of having suffered lead poisoning in a town in East China's Anhui province has found the amounts of lead in their blood were within normal levels, but local officials and parents remain convinced that an unlicensed battery plant is responsible for poisoning their children.

A child who has been diagnosed as having excessive amounts of lead in his blood cries as he receives medical treatment yesterday at a hospital in Hefei, capital of Anhui Province in east China. [Shanghai Daily]

The Anhui provincial health department announced the results of the re-examination on Thursday, while the Huaining county government maintained its view that the illegal battery plant, which it has closed, had produced excessive lead pollution and damaged the health of the town's children.

Meanwhile, the Ministry of Environmental Protection has dispatched an investigation team to Anhui province, China Central Television reported on Thursday.

The provincial health department said in a statement on its website that since Dec 28 more than 200 children from Gaohe township in Huaining county have had blood tests at the Anhui Provincial Children's Hospital.

The hospital in Hefei, capital of Anhui province, conducted tests on those children's peripheral blood and 23 of them were diagnosed with a high blood lead level, the statement said.

However, the province's Center for Disease Control and Prevention collected venous blood from those 23 children for a second test on Wednesday and the results did not find abnormally high levels of lead, the statement said.

Xinhua News Agency reported that the hospital had tested 280 children, of whom 28 (five were newly found to be suffering lead poisoning on Thursday) had been hospitalized for symptoms of lead poisoning.

The hospitalized minors, aged from nine months to 16 years old, were diagnosed with more than 250 micrograms of lead per liter of blood, Cheng Bangning, a doctor at the micro-elements testing laboratory at the hospital told Xinhua.

"My son is now very cranky and restless. He yells a lot," Huang Dazhai, the father of a 5-year-old boy who was found to have 330.9 micrograms of lead per liter of blood, told Xinhua.

Just 100 micrograms per liter is enough to impair brain development in children.

Excessive lead in the blood, particularly in children, can damage the digestive, nervous and reproductive systems.

All hospitalized children were residents from the densely populated Xinshan community in Gaohe township, Xinhua reported.