LANZHOU -- Twenty officials in northwest China's Gansu province have received various punishments for their role in a lead contamination scandal affecting 368 people, a provincial government spokesman said.

From March to August last year, residents from Xinsi, Muba and Liugou villages in Huixian County of Longnan City -- including dozens of children -- were hospitalized with excessive levels of lead in their blood.

Because medical facilities in the area were inadequate, some of the villagers had to travel as far as Xi'an in neighboring Shaanxi Province to be tested.

In October 2006, investigators from the State Environmental Protection Administration determined that the villagers had been poisoned by discharges from a nearby lead smelting plant that had been in operation for 10 years.

Huixian Non-ferrous Metals Smelter Company, the source of contamination, had never operated anti-pollution equipment -- despite being upgraded in 2004 -- and was guilty of illegal waste discharges ever since it began operations in 1996.

At one point discharges from the plant forced the local government to temporarily suspend the supply of water to 80,000 people.

Ran Hong, chairman of the board of directors of the polluting smelter, will be charged with destroying environmental resources, said the provincial government on Tuesday.

When the pollution case became public, Pan Yue, deputy chief of the State Environmental Protection Administration (SEPA) said, "The incident was caused by negligence and malpractice by the local government and environmental departments, and has severely harmed the health of the people."

He said those responsible should be severely punished.

According to a decision by the provincial government, the other 19 officials -- mostly county-level officials and city environmental authorities -- were either sacked or given warnings or demerits.

No information was available at press time about the health status of the children and other villagers. Children can suffer permanent damage from lead poisoning.

Excessive amounts of lead in the body harm the nervous and reproductive systems. Lead also damages the brain and the kidney and causes high blood pressure and anemia.