The smelter discharged 1.11 tons of lead annually, according to Zhao.
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 even death.
"According to international practices, people with constant exposure to lead need regular health exams, including the factory workers and anyone at potential risk," said Wang Dongqing, an environment protection worker based in provincial capital Xi'an.
The scandal has shed light once again on the dilemma facing many parts of China when industrial development poses threat to the environment and people's health.
The smelter, which started production in 2006, contributed to 17 percent of Fengxiang County's GDP last year.
To some extent, the plant also benefited the villagers, some of whom secured factory jobs while others earned extra money by leasing houses to migrant workers or running grocery stores and eateries that were more often frequented by the factory workers than local peasants.
But there was a heavy price to pay.
The county government was supposed to help relocate 581 families living within 500 meters from the factory zone by this year, but 425 of them were never moved.
Official Pu Yiming in Changqing town said relocation was delayed because of readjustments in the overall planning of an industrial park in town, as well as the villagers' reluctance to leave their hometown.
The villagers, however, disagreed.
"It's all because the government and business put economic benefits above people's health," said Sun Yagang, who lives only 100 meters from the plant. "Otherwise, why didn't they wait until after we'd moved to open the plant?"
Sun and most villagers were totally ignorant of the pollution and its harm.
"Had we known better, we wouldn't have stayed here."
The county government has promised to relocate all the remaining 425 families within two years and began building new homes 1,350 meters from the factory site last Thursday.
The Fengxiang environmental protection bureau will strengthen monitoring all the enterprises in the industrial park. Any enterprise that fail the test will be ordered to halt operation, officials said.
The government also pledged free treatment for the young victims.
However, parents remained worried about the health of their children, as the treatment that uses an intravenous drip of calcium disodium edetate could cause adverse reactions including "acute renal failure in a few cases".
Other alternative therapies, including living away from the pollution and nutriment interference, can only remove lead from the body in the long run, said Liu Yaxiang, vice president of the county hospital.
Liu said his hospital received 86 children suffering from lead poisoning. The calcium disodium edetate therapy would be used on only seven children, as parents of others were not willing to take the risks.
"I don't know which therapy to choose," said Liu Hong, one of the mothers.
The villagers believed they suffered more losses than health.
"Now that people know our village is contaminated by lead, they have stopped buying my milk," said villager Wen Guaiyan, who raises four milk cows.
Many other villagers suffered similar losses, unable to sell their vegetables, eggs and other farm produce.
Scared by lead poisoning, parents are considering sending children to other counties for education.