American University has banned smoking, but designated a handful of outdoor areas for smokers to light up during a transition period in the next few months. (Nick Anderson/The Washington Post)

American University’s ban on smoking went into effect Thursday throughout its Northwest Washington campus except for three outdoor spots, where smokers will be able to light up a few more months to help them through the transition.

At least two other local schools have implemented smoking bans this summer: the University of Maryland at College Park and George Washington University. Nationwide, the American Nonsmokers’ Rights Foundation estimates that nearly 1,200 college and university campuses have gone smoke-free. Montgomery College and Towson University were among the leaders of the movement in Maryland.

For many years, AU had banned smoking indoors and within 25 feet of building entrances. But university officials, prodded by student leaders who oppose smoking, decided last year that those limits were not enough.

Now the ban will cover outdoor areas as well.

Three small spots on campus have been set aside for smokers, but just through Dec. 23, when those havens will disappear, too, and smokers will be forced to leave campus to have a cigarette or cigar. In practical terms, that may push many smokers onto the public sidewalks along Massachusetts and Nebraska avenues.

The campus ban also covers the use of chewing tobacco.

A quick look at the outdoor smoking spots Thursday morning found them nearly deserted. One employee who put out his cigarette and deposited the butt into a “smoker’s pole” declined to be interviewed because he was concerned about his job.

James Manning, 19, an undergraduate, sat with his laptop on a shaded bench on the Main Quad, enjoying the unusually crisp late-summer air. He said he was glad that the air was guaranteed to be smoke-free.

“I used to really struggle with asthma as a kid,” Manning said. Smoking, he said, is “terrible for your lungs, smells terrible and is unsanitary, in my opinion.” In previous years, Manning said, he was sometimes forced to endure clouds of smoke outside his dormitory’s entrance. “It’s a pretty big nuisance.”

But Anila D’Mello, 23, a graduate student walking by, said she believes that the ban is unfair. D’Mello said she does not smoke but has friends who do.

“It seems a little extreme,” she said. “Most of campus is an outdoors area.” She said enforcement will be difficult. Her friends who smoke, she said, “think it’s a little bit strange to regulate that.”

Robert D. Hradsky, assistant vice president and dean of students, said the university surveyed students, faculty and staff before deciding on the broader ban. The survey showed that about 10 percent of the campus community smokes.

The primary reason for the ban, he said, is “the health and well-being of the campus.”

Hradsky, interviewed in a small, temporary smoking haven on a bench next to the grassy Kogod Ellipse, said the ban will be enforced in part by “tobacco-free ambassadors,” a small group of students trained to use a low-key, educational approach. They will carry fliers printed by the university that have information about the ban and resources to stop smoking. Anyone spotted smoking will be given a flier.

Repeated and willful violators, Hradsky said, will be subject to disciplinary procedures. But he said he expects such cases to be rare.

“We really see it as a community responsibility,” he said.