On the op-ed page of today's New York Times, Boston University public health professor Michael Siegel argues that outdoor smoking bans like the one that takes effect in New York City on May 23 are unreasonable and may provoke "a backlash that could undermine the basic goals of the antismoking movement." Siegel, a longtime advocate of smoking bans in workplaces (including bars and restaurants), says the scientific case for preventing people from lighting up in outdoor settings such as parks or beaches is "much weaker":
Not only can people move around and thus avoid intense exposure, but smoke quickly disperses in the open air.
True, there is evidence that being near someone smoking, even outdoors, can result in significant secondhand smoke exposure. Researchers at Stanford found that levels of tobacco smoke within three feet of a smoker outside are comparable to inside levels. But no evidence demonstrates that the duration of outdoor exposure —in places where people can move freely about—is long enough to cause substantial health damage.
Siegel faults anti-smoking activists and public health officials for exaggerating the risks posed by transient exposure to tobacco smoke:
Last year the surgeon general's office claimed that "even brief exposure to secondhand smoke can cause cardiovascular disease and could trigger acute cardiac events, such as heart attack," and that "inhaling even the smallest amount of tobacco smoke can also damage your DNA, which can lead to cancer."
However, the surgeon general’s statement conflates the temporary negative effects of secondhand smoke on the circulatory system, which have been shown to occur with short-term exposure, with heart disease, a process that requires repeated exposure and recurring damage to the coronary arteries. It also conflates one-time DNA damage, which occurs with any carcinogenic exposure, with cancer risk, which likewise generally requires repeated exposure.
Siegel worries that such hyperbole damages the scientific credibility of the anti-smoking movement, which seems to be driven by "unthinking hatred of tobacco smoke" rather than legitimate health concerns.
Siegel is right on all of these counts. But it seems to me that the moral case for banning smoking outdoors is stronger that the moral case for banning it in bars and restaurants, since the latter sort of ban involves private property. While the level of exposure is higher inside a bar than it is in a park, no one is forced to enter that bar, whether as a customer or as an employee, and no one but the owner is entitled to decide whether people may smoke there. Public property, by contrast, is owned jointly by taxpayers, the majority of whom may prefer that smoking be banned. Furthermore, public spaces such as Washington Square Park or City Hall are harder to avoid than businesses where smoking is allowed.
That does not necessarily mean a blanket ban is reasonable. To my mind, it is appropriate to restrict or ban smoking inside government buildings, both because exposure is higher and because people (such as jurors, litigants, or crime victims) may have no choice about being there, while banning it in a park seems excessive for the reasons Siegel suggests—and because outside is one of the few places where people are still allowed to smoke. Smokers are taxpayers too, and their interests should be accommodated on public property (which they partly own) unless doing so presents a serious nuisance or hazard to the rest of us. But on public property, the government has to set the rules, while on private property it has no business doing so.
Siegel, who in recent years has specialized in criticizing the excesses of his fellow anti-smoking activists, blogs about tobacco policy here. Last year I discussed the surgeon general's report to which he refers. In 2009 I noted the candid paternalism underlying New York's outdoor smoking ban. More on outdoor smoking bans here and here.