China has shuttered almost 90 percent of lead-acid battery makers in a government crackdown to curb lead poisoning cases, cutting sales and weighing on metal prices, an industry group said yesterday.

Local environmental protection bureaus have inspected 1,744 lead-storage battery makers and only 229 are still operating, Cao Guoqing, vice secretary-general of the China Battery Industry Association, said in an e-mailed response to questions. China is the world's largest exporter of the batteries used in electric bicycles and hybrid vehicles.

Decreasing lead demand may extend a 20 percent decline in prices this year on the London Metal Exchange and squeeze profits at metal makers Henan Yuguang Gold and Lead Co and Shenzhen Zhongjin Lingnan Nonfemet Co. Battery producers, which represent 80 percent of consumption, were shut along with recyclers after hundreds were poisoned in Zhejiang and Guangdong provinces in May and June.

"We would expect this will certainly keep a lid on the price of lead going forward," David Lennox, a resource analyst at Fat Prophets, said yesterday by phone from Sydney. This is not the first time "we are seeing lead being removed from the manufacturing industrial processes. There would be certainly more to come."

Lead has fallen 30 percent from a three-year high of US$2,904 a ton on April 11 on the LME.

"Sales and exports must have been reduced, weighing on lead prices," Cao said. He declined to give an estimate of inventory levels for the about 2,000 lead-acid battery makers in China.

China is seeking to better protect the environment after the economy's size more than doubled in the past five years. The government is accelerating the passage of legislation aimed at preventing heavy metals pollution, Li Ganjie, vice environmental protection minister, said on June 3.

At least 600 people, including 103 children were found to suffer from lead poisoning in Zhejiang, Xinhua news agency said on June 12. Zhejiang and Guangdong are the two biggest producing regions, supplying 36 percent of total output, according to SMM Information & Technology Co.

Excessive amounts of lead in the blood can damage the digestive, nervous and reproductive systems, and cause stomach aches, anemia and convulsions.