HARRISBURG - Three months after the state smoking ban went into effect, its leading champion is seeking to snuff out exemptions that have allowed smokers to continue lighting up at hundreds of establishments.

Sen. Stewart Greenleaf (R., Bucks) author of the Clean Indoor Air Act, said he planned to introduce a bill next week to close the loopholes allowing smoking at casinos, bars and private clubs.

"The scientific evidence is irrefutable," Greenleaf said. "It's not just primary smoke, it's secondary smoke that is injuring and killing people."

The new law, the subject of 15 years of debate in the legislature, makes it illegal to smoke in 95 percent of all workplace and public areas. Exceptions include drinking establishments with less than 20 percent food sales and portions of casinos.

Greenleaf's bill would eliminate those exceptions, ban smoking at outdoor cafes, and allow all municipalities to pass even tougher bans, as Philadelphia has done.

Health-advocacy groups hailed the proposal as a way to dramatically reduce exposure to second-hand smoke.

"Everyone should be guaranteed the right to breathe clean indoor air," said Deborah Brown, vice president of community outreach for the American Lung Association of the Mid-Atlantic. "This would help make sure everyone is protected."

Several surrounding states have tighter bans. In Maryland and Delaware, all bars and casinos are smoke-free. New Jersey bans smoking in all bars and restaurants, but allows smoking on 25 percent of its casino floors, as Pennsylvania does.

Greenleaf's announcement comes as more bars file applications for exemptions, casinos seek to expand smoking on their floors, and even universities challenge the existing ban.

So far, 241 bars and restaurants have been approved for exemptions by the state Department of Health in Delaware, Montgomery, Chester and Bucks Counties. Philadelphia is not included because it enforces its own smoking ban.

Citing high demand, Pennsylvania casino owners are seeking to expand their smoking sections beyond the minimum 25 percent allowed.

PhiladelphiaPark Casino in Bensalem announced earlier this month that it would become the first casino in the state to double the smoking area to one-half of its casino floor after state figures showed that wagering in the smoking area exceeded that of the nonsmoking area by more than 2 1/2 times during the last 90 days.

Under the Clean Indoor Air Act, casinos can increase the size of their smoking areas in proportion to the difference of revenue between smoking and nonsmoking areas to a maximum of 50 percent.

Meanwhile, after objections were raised by employee unions on college campuses, the State System of Higher Education has proposed changes that would permit smoking in certain outdoor areas of college campuses and is considering allowing employees to smoke in their cars with their windows up.

Greenleaf said having exceptions leads to confusion and makes it harder to implement the law.

"Furthermore, they provide for an unlevel playing field when some establishments must comply while others do not," he said.

Greenleaf said that although studies show that restaurants have not been hurt by smoking bans, arguments made by casinos and bars about financial harm were shortsighted.

"It shouldn't be profit ahead of people's lives," Greenleaf said. "Second-hand smoke costs billions in lost work produced and health-care costs. We'll pay the price later for any short-term gains now."

The new bill is nearly certain to face opposition from casinos as well as the Pennsylvania Tavern Association, which represents "mom-and-pop bars." The tavern group, whose spokesman was not available for comment yesterday, fought for and won the exemption for taverns, which allows smoking in establishments where food sales represent only 20 percent of revenue.

A spokesman for Gov. Rendell said the governor, though generally supportive of a more comprehensive approach, would hold off on endorsing any proposal until a final bill passes the General Assembly

"The governor has always believed the fewer exceptions the better, but because politics is the art of the possible, he signed the bill the legislature sent him," Chuck Ardo said. "He will certainly follow the renewed debate with interest to see if it results in a bill reaching his desk."

Contact staff writer Amy Worden at 717-783-2584 or aworden@phillynews.com.