Junk Tobacco Science: Tar Heel Edition

As always, I commend Chris Snowdon’s blog, Velvet Glove, Iron Fist to you as among the very best places for common sense on tobacco issues. His latest post offers a pleasing, if sadly pointless, demolition of a North Carolina study claiming that a ban on smoking in bars caused a 21% fall in the number of heart attacks in the Tar Heel state. Poppycock but the sort of tripe that’s accepted by press and politicians alike. As Chris explains:

Even if we assume that secondhand smoke does cause heart attacks, smoking bans have so little effect on so few non-smokers (and have no effect at all on the smokers, unless it compels them to quit), that the kind of reductions in the heart attack rate reported by these studies defy both science and common sense. If there is an effect, it is too small to measure and would never show up in population-level statistics. Once that is understood, it is obvious that any studies which claim a dramatic effect on the heart attack rate must be flawed, cherry-picked or distorted. Sure enough, when such studies are examined, they prove to be flawed, cherry-picked and distorted.

[…] If, to take North Carolina as an example, the smoking ban caused the heart attack rate to drop by 21%—which it unequivocally did not—it follows that smoking in bars, restaurants and offices must have been responsible for a fifth of all heart attacks before the ban.

It is quite possible that thirty years of induced panic about passive smoking has persuaded many people that such diluted tobacco smoke is capable of wreaking such havoc, but the empirical evidence shows that it cannot be so. If it were, the relative risk from secondhand smoke exposure would be far higher than 20-30%. Indeed, secondhand smoke would be responsible for more heart attacks than smoking. It would mean that passive smoking (at work and at home) was the single biggest risk factor for heart attacks. Even the most tobaccophobic hypochondriac surely cannot believe such a thing.