Tuesday, June 27, 2006

Media Already Reporting that 30 Minutes of Secondhand Smoke Causes Blood Clots in Arteries; Does the Surgeon General's Report Really Matter?

The Omaha World-Herald reported yesterday that just 30 minutes of secondhand smoke increases a nonsmoker's risk of developing blood clots in his or her arteries. According to the article: "Within a half-hour, the platelets in a person's blood vessels become stickier, increasing the likelihood of clots...".

It's not clear exactly where this information came from, but it's a good bet that it originated from one of the 80+ anti-smoking groups which are claiming that just a half-hour (or less) of exposure to secondhand smoke causes hardening of the arteries, clogged arteries, blood clots in arteries, catastrophic arrhythmias, heart attacks, and death.

The World-Herald also reported that: "For at least eight hours after leaving a smoky bar, the effects remain in the blood system - with the contaminants themselves remaining much longer."

The Rest of the Story

On the day that a new Surgeon General's report will be released which focuses on the health effects of secondhand smoke, it's not clear to me why we need a new Surgeon General's report.

If anti-smoking groups are already spreading word that just 30 minutes of secondhand smoke causes clotting of the arteries and can kill you, then it seems to me that we really don't need a detailed scientific report on the actual, documented effects of secondhand smoke.

Why does it really matter what the actual, documented effects are if anti-smoking groups are simply going to over-dramatize the situation and make up whatever alarming claims they want to? Let's face it. The 30-minute claim is a "made-up" claim; it is not based on scientific evidence:
  • There is no evidence that 30 minutes of secondhand smoke exposure causes hardening of the arteries.
  • There is no evidence that 30 minutes of secondhand smoke exposure causes reduced coronary blood flow.
  • There is no evidence that 30 minutes of secondhand smoke exposure causes narrowed or clogged arteries.
  • There is no evidence that 30 minutes of secondhand smoke exposure causes blood clots.
  • There is no evidence that 30 minutes of secondhand smoke exposure causes fatal or catastrophic cardiac arrhythmias.
  • There is no evidence that 30 minutes of secondhand smoke exposure causes heart attacks or death.
There is, in fact, no scientific evidence that a single 30 minute exposure to secondhand smoke poses any significant acute cardiovascular health threat to anyone other than someone who already has coronary artery disease.

But anti-smoking groups are widely going around making these claims, and the media are clearly picking up on this and reporting the fallacious claims to the public.

It's also not clear where the paper got the idea that the risk of suffering a blood clot in an artery from secondhand smoke lasts for 8 hours after leaving a smoky bar, but I'd bet that it came from an anti-smoking group which is attempting to sensationalize the health threat posed by acute secondhand smoke exposure in order to promote smoking bans.

The truth is that the effects of acute secondhand smoke exposure on aortic elasticity reversed completely within 15 minutes of discontinuation of exposure. So it's misleading to suggest that the "artery-stiffening" effect of secondhand smoke lasts for 8 hours. Even the platelet-aggregatory effects of secondhand smoke only lasted for 6 hours, so it's not clear where the 8 hour figure comes from. But since the alleged risk of suffering a blood clot from 30 minutes of secondhand smoke is not a documented one, I guess it doesn't really matter how long one claims that "effect" lasts.

While we all await the release, later today, of the Surgeon General's report on the health effects of secondhand smoke, I am less than convinced that the report has any significance. If we're going to make up our health claims in order to sensationalize them, then who cares what the actual scientific evidence shows?

No comments: