Thirty-nine children in southwest China's Yunnan Province were found to have excessive lead levels in their blood, local authorities said Friday.

A two-week health check period in Beiyapian District, Heqing County earlier this month showed excessive levels in blood samples of 39 children under the age of 14, said the county government in a statement.

The sick children were hospitalized.

However, the statement did not mention the conditions of those kids.

The health checks followed a crackdown by the local environmental protection department on illegal gold metallurgy activities, which could generate lead fumes and poisonous solid waste.

An initial investigation showed that the children might have breathed lead fumes discharged from illegal gold metallurgy workshops owned by some villagers.

The county government is still investigating the cause of the poisoning.

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, comas and even death.