BEIJING — China will relocate 1,400 families who live near a smelter that caused lead poisoning in about 850 children this year, state media said Friday.

Authorities in Fengxiang county in northern Shaanxi province said the families will be moved into new homes at least four kilometres from the smelter before the end of next year, the official Xinhua News Agency said.

The families all live within 1,000 metres of the Dongling Lead and Zinc Smelting Co.

The company, which was shut down amid protests in August, has agreed to pay part of the 300 million yuan (US$44 million) relocation cost, splitting it with local governments.

China's rapid economic development has often come at the cost of heavy environmental pollution. The smelter, which produces 100,000 tons of lead and zinc and 700,000 tons of coke a year, contributed 17 per cent to the county's economic production last year.

Similar reports of lead poisoning have emerged in Yunnan, Fujian and Shaanxi provinces in recent months, affecting more than 3,000 children.

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

Deputy county chief He Hongnian was quoted saying construction of two new residential areas began in September.

A total of 851 children in the area were diagnosed with lead poisoning. Some had lead levels 10 times the amount China considers safe.

Xinhua said a few serious cases remain hospitalized, but a third of the children have fully recovered and the others are receiving dietary treatment for their illness.