Fifty-three people were hospitalized after tests found that 332 residents in Deqing, near a factory making lead-acid motorcycle batteries, had elevated levels of lead in their blood, the local government said in a statement.

Most were workers at the Zhejiang Haijiu Battery Co. or members of their families, it said.

Heavy metals poisoning is an urgent concern in China, where safety standards are often disregarded by manufacturers and local officials.

China has had hundreds of pollution emergencies in recent years, many involving heavy metal contamination. Thousands of children were affected by lead poisoning in several provinces in 2009 and 2010 because they lived near metal smelters or battery factories.

The government said Monday that eight local officials also were under investigation after authorities found the factory, located in a scenic rural area about 90 miles (150 kilometers) southwest of Shanghai, improperly disposed of factory waste.

The discovery prompted orders for a safety check of all 273 battery factories in Zhejiang province, where the factory is located.

More than 2,000 people were given blood tests as medical and environmental experts were sent to the area.

Officials in Deqing have been eager to demonstrate the government's rapid response to the problem. Monday's statement noted that tests last week showed soil and water samples already had been restored to acceptable levels. But there has been no official word on exactly how residents suffered such widespread lead contamination in the first place.

Zhejiang Haijiu Battery was ordered to suspend operations in Deqing. According to state media reports, the company has pledged to pay for treatment for those sickened by the lead emissions.

Lead poisoning can damage the nervous, muscular and reproductive systems. Children are particularly at risk.