The list of places where smokers can legally light up just got a little shorter Thursday, as a San Diego ordinance banning smoking at beaches and parks officially took effect.

A small and admittedly unscientific survey of local parkgoers in North County showed generally strong support for the ban -- but it was not unanimous, even among nonsmokers.

At Rancho Penasquitos Park, Linda Garro, a credit manager, and Lillian Thurston, a photographer, were grooming their horses in the Equestrian area. Garro said the law wouldn't personally affect her.

"To be honest, it doesn't matter one way or the other," Garro said. "I don't smoke. As long as I don't have to go into a restaurant where there's smoke -- or a bar. But I don't mind (smoke) outside."

Thurston expressed both acceptance of the ban and a certain defiance.

"I'm a smoker, and I don't like the law," she said. "But I understand it because most smokers don't respect nonsmokers."

The law's supporters cite the problems of litter and public health as justification for the ordinance. Thurston said she scrupulously avoided making a mess with her cigarettes, but said many smokers were not so considerate.

"They throw their butts down on the ground and I don't," Thurston said. "So I don't like (the ban) but I don't blame (lawmakers) for doing it."

By the same token, she said the ban wouldn't force her to smoke less, much less kick her habit.

"I won't go to parks," she said. "I won't go to beaches."

"Now you can't smoke on the beach, right?" Garro asked rhetorically. "OK, I can't get a cop to come to my house, and you're going to have somebody patrolling down there looking for smokers? Hello?"

Joe Crilly, a construction foreman, offered his opinion from the roof of a seismic retrofit job nearby.

"Got no problem with it," he said. "Can't smoke on any of our jobs, and none of us are smokers."

His reaction to smokers who contested the validity of the science used by ban proponents was a shrug: "I don't know man. Go smoke in your car."

John Porowski, a postman at the Rancho Bernardo post office and a nonsmoker, was getting ready to take a hike by the baseball field.

"I don't understand the whole thing," Porowski said. "I don't particularly care for the smell or anything. But I don't lean toward the side that thinks second-hand smoke causes anything. I think that's rubbish."

At Rancho Bernardo Park, Jerry Massie, a retired engineer and an ex-smoker, voiced his support for the law.

"I'm all for it," he said. "I don't mind 'em smoking per se -- that's their own personal preference. If they want to die from lung problems, that's up to them. But I do dislike the fact that they throw their butts down all over the place."

But Nelly Bulkin, a nonsmoker and homemaker who was supervising her two young boys as they roller-skated nearby, had a different opinion.

"I think that smoking outside should be a matter of personal choice," Bulkin said. "I understand the ban indoors, but I think that when you're in an outdoor setting (smoking) doesn't cause that much pollution to the air -- you should be able to smoke outside."

Samantha Bowman is the executive director for Coronado SAFE (Substance Abuse Free Environment), a local group that worked with a broad anti-tobacco coalition, including the San Diego chapter of the American Lung Association, to draft and pass the ban.

"We're thrilled and we're looking forward to working with the community in an educational way, so that they could better understand how harmful tobacco is to themselves and to those around them," she said in a phone interview.

She dismissed the argument made by some that enforcement would be difficult and expensive.

"If a person who smokes lights up, they're often reminded by those around them that smoking is not allowed at that particular location, and most people are very cognizant about wanting to be good citizens and wanting to follow the law," Bowman said.

But Jacob Sullum, an award-winning journalist and author of the book "For Your Own Good -- The Anti-Smoking Crusade and the Tyranny of Public Health", said there were serious questions about the ban's social impact, effectiveness and scientific grounding.

"I suspect that it will result in a lot of acrimony and confrontations if you're telling nonsmokers that they are now charged with enforcing this law -- that sounds like a recipe for a lot of fights. And in the end I'm not sure it's going to save police resources because they still have to follow up and issue the fines or whatever it takes to enforce the ordinance."

Sullum, who was also reached by phone, said the risk of second-hand smoke to bystanders -- even in an indoor setting -- was vanishingly small.

"All the epidemiological studies that look at second-hand smoke deal with intense long-term exposure of the kind that you get from living with a smoker for decades," he said. "And even those studies generally find weak associations, often statistically insignificant."

But for now the question of statistical significance is moot; the ban was approved unanimously by the San Diego City Council. Bowman said the fine for violators was up to a $1,000.

"Whatever the cost, it's certainly less than the cost of smoking to their health," she said. "For some, this will provide just that little nudge to get them to quit."