The number of mainland Chinese at risk from second-hand smoke increased to 740 million as of August, up from 540 million in 2007, Yang Gonghuan, director of the National Tobacco Control Office, said at a forum over the weekend.

Each year, more than 100,000 of them die from diseases related to second-hand smoke, she said.

To protect non-smokers from passive smoking and its related health hazards, Yang called for nationwide legislation to ban smoking in public places.