Environment authorities said on Saturday a smelter is mainly to blame for a lead poisoning that sickened 615 kids in northwest China's Shaanxi Province.

But "other factors" cannot be ruled out, such as auto exhausts, home decoration, diet and living habits, said Han Qinyou, head of the Baoji Municipal Environmental Protection Monitoring Station, at a press conference.

At least 615 children, out of the total 731 under the age of 14 living in two villages near the Dongling Lead and Zinc Smelting Co. at Changqing Township of Fengxiang County in Baoji, have shown excessive amounts of blood lead after medical tests.

Residents from the Madaokou and Sunjianantou villages that are adjacent to the company believed that children's sicknesses are linked to environmental pollution caused by the smelter.

"We collected 69 samples of groundwater, surface water, soil, air and sewage in the area to check for contamination," Han said. "The results show that the groundwater, surface water, soil and the company's waste discharge have all met the national standards, but lead content in the air along the main roads near the company is 6.3 times that of the monitoring sites 350 meters away from the roads."

The official would not specify whether there has been an air pollution.

"What we will do next is to speed up the relocation of nearby residents, order the company to improve its ways of waste discharge and carry out further environmental assessment in the area," he added.

The smelting plant belongs to Dongling Group, one of the biggest private companies in Shaanxi Province. The plant in Changqing town began operating in 2006, producing 100,000 tonnes of lead and zinc and 700,000 tonnes of coke annually. It contributed 17 percent of the county's GDP last year.

Local authorities ordered the closure of the smelting plant on Aug. 6, about two weeks after the first lead poisoning case was reported in 6-year-old Miao Fan.

Zhao Weiping, vice Communist Party secretary of the Dongling Group, offered an apology to local residents at the press conference on Saturday.

"We will cooperate with the government to treat the sickened children and improve our work in light of the requirements of environment authorities," he said.

Of the 615 children, 166 were diagnosed as lead poisoning patients and need to be hospitalized. The lead content in their blood has exceeded 250 micrograms per liter.

"So far, 154 kids have been hospitalized. The other 12 are being admitted to hospital," He Hongnian, executive deputy head of Fengxiang County, told the press conference. "Their medical expenses will be covered by the county government."

"The rest should be able to expel the excessive lead from their bodies through nonmedical treatments at home. The government will send milk, dried vegetables and dried fruits to them starting tomorrow," he said.

The county government had pledged, in a deal reached before the plant was opened, to relocate all residents living within a radius of 500 meters to the plant in three years. But the relocation was behind schedule -- of all the 581 families that should have been relocated by now, only 156 have moved to new homes.

The county government promised earlier this week to speed up relocation and to ensure that all the remaining 425 families would be relocated to a new site 1,350 meters away from the smelter within two years.

"To eliminate their worries about whether the new site could rid of the lead pollution completely, we will invite experts on architecture, environmental protection and meteorology to give an evaluation next week," He said.

(Xinhua News Agency August 16, 2009)