Restaurants and office buildings in China's commercial capital Shanghai are scrambling to set up nonsmoking areas as the city bans lighting up in indoor public spaces ahead of the World Expo.

There is rising awareness of the health risks of smoking in China, by far the world's biggest tobacco-consuming country, and this modern city of 20 million is cleaning up its act as it prepares to host the Expo, which begins May 1.

That six-month event, which will showcase the theme "Better City, Better Life," is expected to attract 70 million people, with exhibits from 192 countries. Most of the visitors will be Chinese from other cities where tobacco use is less strictly controlled.

Getting people to comply with the rules is likely to prove difficult, many feel.

"The regulations are not going to work. China is at least 50 years behind advanced countries, and people here lack self-discipline," said Xu Baofeng, a manager at a mobile phone service outlet, who was standing inside the shop with his head sticking outdoor as he smoked.

"You can see the NO SMOKING sign on our wall, but many people just ignore it," Xu said, saying that some male customers fight back or complain to higher managers if staff try to stop them.

Even before the ban took effect Monday, most major public facilities in Shanghai, including many shopping malls and all subways and subway stations, banned smoking.

Now authorities have penalties to apply, and have signed up thousands of volunteers to help enforce the ban.

First-time offenders will get a warning. If they resist, they face fines of 50 yuan to 200 yuan ($7 to $30).

In response, downtown office buildings are now distributing notices about new indoor smoking areas. Workers routinely smoke in hallways and elevator lobbies.

Most restaurants are only offering token moves, such as designating areas for nonsmokers that are not truly smoke free. At one downtown Internet cafe Tuesday, video game players were puffing away freely. A manager said he wouldn't encourage people to smoke but felt he had no right to stop them.

People are still free to light up on sidewalks and streets.

China accounts for more than one-quarter of the world's 1.3 billion smokers, and any newcomer to the country is hit by the pervasive smell of tobacco smoke on exiting any airport or train station. The Chinese buy a total 2 trillion cigarettes a year.

Key targets of the bans for Shanghai and other cities are hospitals, where patients complain about doctors lighting up.

Under a U.N. treaty, Beijing pledged to ban indoor smoking in public places four years ago. Like neighboring Japan, it has been gradually limiting where smokers can light up.

But such steps face stiff resistance from retailers and local governments that profit from tobacco taxes.

Guangzhou, a city in southern China, banned smoking in public places on a trial basis in 2007. But it reimposed the ban last fall, apparently having failed to enforce it earlier.

Seven other cities recently announced plans for such bans: Chongqing, Tianjin, Shenyang, Harbin, Nanchang, Lanzhou and Shenzhen.

But even Shanghai's state-run newspapers seemed skeptical.

"Who will do the fining? Who do they report to?" read the headline in the Oriental Morning Post.