State media in China report that almost 1000 children have tested positive for lead poisoning in Henan province.
The has been a spate of reported lead poisoning incidents around China recently, with protests over pollution from three smelters by residents in the city of Jiyuan, last month.
After tests on more than 2,700 children under the age of 14, health authorities have found 968 had excessive levels of lead.
Xinhua news agency said all children living within 1000 metres of the three smelters, have now been removed from the area.
The agency also reports there was a mass lead poisoning case in neighbouring Shaanxi province in August when 851 children tested positive for excessive lead levels in their blood, leading to the hospitalisation of 174.