Only a quarter of Chinese people believe that smoking tobacco increases the risk of cancer. And anti-smoking campaigns are failing to influence them, according to a government survey.

Three quarters of people in China are regularly exposed to second-hand smoke, often in the workplace, in a country that puffs its way through around a third of the world's cigarettes.

The survey, conducted by the country's Center for Disease Control and Prevention, showed that barely one in four adults believes smoking increases the risks of lung cancer, strokes and heart attacks.

In a country where 301 million people smoke, only 16 percent are looking to quit in the coming year, perhaps due to a lack of understanding about the dangers.

Over half of Chinese men smoke, compared to just 2.4 percent of women, according to the China section of the "Global Adult Tobacco Survey."

A million people die each year from smoking-related illnesses, yet China's Ministry of Health banned smoking in hospitals only this May.

"Chronic conditions now constitute the lion's share of the burden of disease in China, and tobacco use is the single largest preventable cause of death and disease," said the World Health Organization's China representative, Michael O'Leary.

Both anti-smoking campaigns and cigarettes ads had little impact on most people, the survey found. Only one in five remembered seeing marketing, and less than half noticed health warnings on television or radio.

Less smoking could reduce smoking-related health costs, but would also hurt government revenues, as the tobacco industry still provides a steady flow of government income.

Last year a county government in central China ordered government workers to smoke a combined minimum of 23,000 packs of cigarettes a year to boost tax income, with punishments for those who failed to light up enough. The order was revoked after it created an uproar in the media.