>Presumably, we are grown-up people, with a civilized sense of fair play, and dedicated to disciplined and rational discourse. We are fortunate enough to live in a free country that is respectful of individual choices and rights, including the right to honest public policies. Still, while much is voiced about the merits of forceful advocacy, not enough is said about the fundamental requisite of advancing public health with sustainable evidence, rather than by dangerous, wanton conjectures.
That admirable goal, however, is not advanced by this sort of thing:
>Lung cancer and cardiovascular diseases develop at advancing ages. Estimating the risk of those diseases posed by secondhand smoke requires knowing the sum of momentary secondhand smoke doses that nonsmokers have internalized over their lifetimes. Such lifetime summations of instant doses are obviously impossible, because concentrations of secondhand smoke in the air, individual rates of inhalation, and metabolic transformations vary from moment to moment, year after year, location to location.
I’m not a scientist. But even I can tell the difference between reasonable objections to basic methodology and pushing goalposts back a little (or in this case a lot further). For, on Dr.Gori’s argument, assessing the effects of secondhand smoke is “impossible.” He continues:
>In an effort to circumvent this capital obstacle, all secondhand smoke studies have estimated risk using a misleading marker of “lifetime exposure.” Yet, instant exposures also vary uncontrollably over time, so lifetime summations of exposure could not be, and were not, measured.
>Typically, the studies asked 60–70 year-old self-declared nonsmokers to recall how many cigarettes, cigars or pipes might have been smoked in their presence during their lifetimes, how thick the smoke might have been in the rooms, whether the windows were open, and similar vagaries. Obtained mostly during brief phone interviews, answers were then recorded as precise measures of lifetime individual exposures.
>In reality, it is impossible to summarize accurately from momentary and vague recalls, and with an absurd expectation of precision, the total exposure to secondhand smoke over more than a half-century of a person’s lifetime. No measure of cumulative lifetime secondhand smoke exposure was ever possible, so the epidemiologic studies estimated risk based not only on an improper marker of exposure, but also on exposure data that are illusory.
Don’t forget to undermine the credibility of the witness:
>Adding confusion, people with lung cancer or cardiovascular disease are prone to amplify their recall of secondhand smoke exposure. Others will fib about being nonsmokers and will contaminate the results. More than two dozen causes of lung cancer are reported in the professional literature, and over 200 for cardiovascular diseases; their likely intrusions have never been credibly measured and controlled in secondhand smoke studies. Thus, the claimed risks are doubly deceptive because of interferences that could not be calculated and corrected.
Lastly, there are good arguments on both sides:
>In addition, results are not consistently reproducible. The majority of studies do not report a statistically significant change in risk from secondhand smoke exposure, some studies show an increase in risk, and ¿ astoundingly ¿ some show a reduction of risk.
A more reasonable interpretation of that situation would be this: assessing secondhand smoke is very tricky, and much like assessing any cancer risk, it involves probabilities and factors that often elude the kind of painful exactitude we would like to demand from our science, but as a matter of fact, almost never get. No one but those ignorant of statistics and the meaning of basic scientific studies–oh, I can think of certain Chief Executives and senators–would make such an absurd demand on that kind of evidence. The bar is too high: count how many times Dr.Gori says “impossible” or denies that the thing in question is not subject to proof. That’s a very decisive conclusion for a scientist. Few I think would agree that such a thing is impossible from the outset. Difficult maybe. But not impossible.
Finally, the careful reader will also note the very narrow scope of Dr.Gori’s analysis: to deny that the evidence shows a decisive causal connection between secondhand smoke and lung cancer and cardiovascular disease. Even if he’s right about that specific and narrow claim, that doesn’t mean secondhand smoke doesn’t play a role in either increasing the risk for those ailments or in exacerbating others.
In the end, there is a more basic question of burden of proof here. At this point, the burden rests with the one who claims that living and working in a smoky environment isn’t bad for you.