The American screen has long been a smoky place, at least since 1942's Now, Voyager, in wh

ich Bette Davis and Paul Henreid showed how to make and seal a romantic deal over a pair of cigarettes that were smoldering as much as the stars. Today cigarettes are more common on screen than at any other time since midcentury: 75% of all Hollywood films—including 36% of those rated G or PG—show tobacco use, according to a 2006 survey by the University of California, San Francisco.

Audiences, especially kids, are taking notice. Two recent studies, published in Lancet and Pediatrics, have found that among children as young as 10, those exposed to the most screen smoking are up to 2.7 times as likely as others to pick up the habit. Worse, it's the ones from nonsmoking homes who are hit the hardest. Now the Harvard School of Public Health (HSPH)—the folks behind the designated-driver campaign—are pushing to get the smokes off the screen. "Some movies show kids up to 14 incidents of smoking per hour", says Barry Bloom, HSPH's dean. "We're in the business of preventing disease, and cigarettes are the No. 1 preventable cause".

Harvard long believed that getting cigarettes out of movies could have as powerful an effect, but it wouldn't be easy. Cigarette makers had a history of striking product-placement deals with Hollywood, and while the 1998 tobacco settlement prevents that, nothing stops directors from incorporating smoking into scenes on their own. In 1999 Harvard began holding one-on-one meetings with studio execs trying to change that, and last year the Motion Picture Association of America flung the door open, inviting Bloom to make a presentation in February to all the studios. Harvard's advice was direct: Get the butts entirely out, or at least make smoking unappealing.

A few films provide a glimpse of what a no-smoking or low-smoking Hollywood would be like. Producer Lindsay Doran, who once helped persuade director John Hughes to keep Ferris Bueller smoke-free in the 1980s hit, wanted to do the same for the leads of her 2006 movie Stranger Than Fiction. When a writer convinced her that the character played by Emma Thompson had to smoke, Doran relented, but from the way Thompson hacks her way through the film and snuffs out her cigarettes in a palmful of spit, it's clear the glamour's gone. And remember all the smoking in The Devil Wears Prada？ No？ That's because the producers of that film kept it out entirely—even in a story that travels from the US fashion world to Paris, two of the most tobacco-happy places on earth. "No one smoked in that movie", says Doran, "and no one noticed".

Such movies are hardly the rule, but the pressure is growing. Like smokers, studios may conclude that quitting the habit is not just a lot healthier but also a lot smarter.

Why the author mentioned Now, Voyager？

A．Smoke on screen can make romance.

B．To show American screen was full of cigarette smoke.

C．To explain why cigarettes are easier to get than past.

D．The romantic Hollywood movie is a typical example of smoky screen.