A half-century after the historic U.S. surgeon general's finding that smoking sickens and kills, the Philadelphia region could be viewed as one of the nation's key battlegrounds in the continuing struggle to stem the health scourge, which leads to 443,000 deaths a year and costs billions of dollars in medical care and lost productivity.

Despite the remarkable success in reducing national smoking rates by more than half - to 18 percent - Philadelphia stands out as having the highest rate of adult smoking, around 25 percent, among the country's 10 largest cities, according to the Pennsylvania Medical Society.

While most workplaces and public buildings in Philadelphia have been smoke-free by law for the last seven years - and similar statewide restrictions took effect more than five years ago - an unacceptable loophole permitting smoking at casinos exposes thousands of employees and untold numbers of patrons to dangerous secondhand smoke. With the city's second casino expected to open in the next couple of years - joining four already operating within a short drive of each other - that exemption only promises to do more harm.

On the front lines in the war against smoking, where the challenge is to prevent teens from taking up the addictive habit in the first place, the city bests the national rate of smoking among high school students. But the ease with which so many underage smokers can buy cigarettes illegally in Philadelphia, according to antismoking activists, could make it difficult to cut the rate further.

Furthermore, neither Philadelphia nor Harrisburg has addressed the potential health and social issues surrounding the emergence of electronic cigarettes. Although the battery-powered devices are not nearly as harmful as cigarettes, they still deliver addictive nicotine, and they have been included in indoor smoking bans in New York City and a handful of states, including New Jersey. Pennsylvania has yet to consider such a move or to impose any age restrictions on the purchase of e-cigarettes.

The region's success in carrying out the antismoking efforts inaugurated 50 years ago by Surgeon General Luther L. Terry will depend partly on federal regulators' welcome but fledgling efforts to discourage smoking with graphic labels and marketing limits. But city health officials should also look to state lawmakers for action to close the smoking-ban loopholes that expose workers and patrons at casinos and hundreds of other establishments to secondhand smoke. A more inclusive ban on lighting up indoors - as State Sen. Stewart Greenleaf (R., Montgomery) and State Rep. Mario Scavello (R., Monroe) have proposed - could help thousands more smokers kick the habit.

Beefing up enforcement efforts targeting retailers who sell to underage teens would similarly boost the region's fight against smoking. So would an agreement between lawmakers and Gov. Corbett to finally levy taxes on chewing tobacco and cigars. Continuing such efforts against smoking is the best way to commemorate the surgeon general's groundbreaking report.