You can’t go out and smoke in a park in New York, and if some Manhattan co-ops have their way, some city residents won’t be able stay in and smoke, either. At least six co-op boards are considering a measure making it illegal for people to smoke in their own apartments, taking cues from the city’s far-reaching anti-smoking campaign that has extended the ban to parks, pedestrian plazas and public beaches. Proponents cite health concerns and the unpleasant smell of smoke as reasons to push through the ban. Opponents of the apartment smoking ban say it breaches residents’ constitutional right to privacy. Some further argue that such a ban could keep away renters and buyers who smoke, thereby decreasing property values.