China's Ministry of Health estimates that secondhand smoke kills more than 100,000 Chinese citizens each year, Xinhua reported May 30.

In its 2007 Report on China's Smoking Control, the ministry also said that 540 million Chinese are exposed to secondhand smoke, but just 35 percent knew that passive smoking presents danger to the health of nonsmokers.

Among those exposed to secondhand smoke, 82 percent said they inhaled others' tobacco smoke at home, 67 percent were exposed in public places, and 35 percent were exposed at work. Rural residents were more likely to be exposed to secondhand smoke than urbanites.

"We hope the report can promote authorities to institute and implement laws or regulations to prevent passive smoking inside public buildings," said Yang Gonghuan, deputy director of China's National Center for Disease Control and Prevention.