Tuesday, October 31, 2006

SmokeFreeOhio Misrepresenting Scientific Research in Backing Up Unsubstantiated Health Claim

In support of its efforts to promote Issue 5, which would ban smoking in all Ohio workplaces, bars, and restaurants, SmokeFreeOhio is publicly claiming that secondhand smoke causes pulmonary emphysema.

According to its secondhand smoke fact sheet: "Secondhand smoke can cause the debilitating disease pulmonary emphysema, causing severe damage to the walls of the air sacs, with the lungs eventually losing their capacity to expand and contract."

To back up this claim, which is unsupported (and actually contradicted) by the U.S. Surgeon General's report on involuntary smoking and by the California EPA report, SmokeFreeOhio cites a single study: reference 14 on its fact sheet.

Citing this scientific reference - a study published in the American Journal of Physiology - makes it appear to the public as though the claim made by SmokeFreeOhio is documented in the scientific literature.

Curious to see the research that SmokeFreeOhio was using to substantiate its claim that secondhand smoke causes pulmonary emphysema, I examined the article.

It is also worth noting that when I corresponded with a representative of SmokeFreeOhio and expressed my concerns that the documentation to support a causal link between secondhand smoke and emphysema was inadequate, the representative responded by suggesting that if I had a problem, I should take it up with the authors of that paper.

So here's what the authors of that paper had to say in the article's abstract:

"Cigarette smoke is a mixture of chemicals having direct and/or indirect toxic effects on different lung cells. We investigated the effect of cigarette smoke on human lung fibroblasts (HFL-1) oxidation and apoptosis. Cells were exposed to various concentrations (1, 5, and 10%) of cigarette smoke extract (CSE) for 3 h, and oxidative stress and apoptosis were assessed by fluorescenceactivated cell sorting and confocal laser fluorescence microscopy. Both oxidative stress and apoptosis exhibited a doseresponse relationship with CSE concentrations. Lung fibroblasts also showed marked DNA fragmentation at the Comet assay after exposure to 10% CSE. Coincubation of HLF-1 cells with N-acetylcysteine (1 mM) during CSE exposure significantly reduced oxidative stress, apoptosis, and DNA fragmentation, whereas preincubation (3 h) with the glutathione- depleting agent buthionine sulfoximine (125 uM) produced a significant increase of oxidative stress. Cigarette smoke is a potent source of oxidative stress, DNA damage, and apoptosis for HFL-1 cells, and we speculate that this could contribute to the development of pulmonary emphysema in the lungs of smokers."

(Carnevali, S., Petruzzeli, S., Longoni, B., Vanacore, R., Barale, R., Cipollini, M., Scatena, F., Paggiaro, P., Celi, A., Giuntini, C. (2003, June). Cigarette smoke extract induces oxidative stress and apoptosis in human lung fibroblasts. American Journal of Physiology, 284, 955-964)

The Rest of the Story

There's just one minor problem with the use of this article to back up SmokeFreeOhio's claim: this article concludes that damage to fibroblasts can contribute to the development of pulmonary emphysema in the lungs of smokers, not nonsmokers. A minor technicality? Hardly.

The rest of the story is that SmokeFreeOhio is completely misrepresenting this scientific research to the public. They are presenting this research as supporting the conclusion that secondhand smoke causes pulmonary emphysema in nonsmokers. But what the article actually concludes is that tobacco smoke induces oxidative stress and apoptosis in fibroblasts in the lung, providing a potential mechanism by which active smoking contributes to the development of pulmonary emphysema.

In fact, nowhere in the paper does it even suggest that secondhand smoke can cause emphysema in nonsmokers.

This doesn't look good. Because it makes it appear that SmokeFreeOhio is intentionally misrepresenting the science in order to support its apparently untenable position.

I suppose one could argue that this was simply a mistake. But it seems hard to misread the clear conclusion of the paper. It concludes that the observed damage to lung fibroblasts could contribute to the development of pulmonary emphysema in the lungs of smokers. Even if one didn't read the rest of the article, one would still see that the article is referring to emphysema among smokers, not nonsmokers. It seems as clear as day to me. I don't think you even need to be a scientist to read the conclusion and understand that it is talking about smokers. After all, it says: smokers.

You can see why it is difficult for me to conclude anything other than that SmokeFreeOhio is intentionally misrepresenting this scientific research.

By the way, even if this article did postulate that tobacco smoke could contribute to the development of emphysema among nonsmokers, it is a far cry from being adequate documentation to support a conclusion that secondhand smoke causes emphysema. This is a study of the effect of tobacco smoke extract on human lung cells. The study does not involve actual people. It does not involve the identification of any actual cases of emphysema among nonsmokers. So it in no way provides support for a conclusion that secondhand smoke causes emphysema among nonsmokers.

To make matters worse, this is not the only misrepresentation of the science in SmokeFreeOhio's campaign. The group also claims that: "Secondhand smoke exposure increases your risk of developing pancreatic cancer." To back up this claim - which is unsupported by both the U.S. Surgeon General's report and the California EPA report - SmokeFreeOhio relies upon a single study: reference 15 on its fact sheet.

Curious about the evidence that would support SmokeFreeOhio making a claim, based on a single study, that is unsupported by the Surgeon General and the California EPA, I examined this study.

The basic conclusion of the study was as follows: "Among never smokers, those who were exposed to ETS both as a child and as an adult had an odds ratio of 1.21 (95% CI=0.60-2.44) relative to those with no exposure." (Villeneuve, P., Johnson, K., Mao, Y., Hanley, A. [2004, Jan.-Feb.] Environmental tobacco smoke and the risk of pancreatic cancer: Findings from a Canadian population-based case-control study. Canadian Journal of Public Health, 95(1), 32-7).

In other words, the study found no significant increase in the risk of pancreatic cancer among passive smokers.

For those unfamiliar with epidemiology, if the odds ratio for pancreatic cancer associated with passive smoking was 1.0, it would indicate no increased risk. If the 95% confidence interval around the study's estimate for the odds ratio includes 1.0, then the study is unable to conclude that there was a significant increase in pancreatic cancer risk among nonsmokers. In this study, the lower end of the confidence interval is 0.60. In other words, it is quite possible that nonsmokers exposed to secondhand smoke were only 0.6 times as likely to get pancreatic cancer. From this study, one cannot even conclude that secondhand smoke doesn't have a protective effect against pancreatic cancer.

Obviously, secondhand smoke doesn't have a protective effect. But the point is simply that the study found no significant elevation of risk among nonsmokers, and the results weren't even close to being statistically significant.

Does this mean that secondhand smoke does not cause a slight increase in pancreatic cancer risk? No. But it does mean that this single study cannot be used to back up the claim that secondhand smoke causes pancreatic cancer. In my opinion, SmokeFreeOhio is again misrepresenting the scientific research in order to create the appearance of their being scientific support for the claim that it is making.

This truly is deception. There's just no way around it any more. You can't put together this combination of misrepresented scientific findings to create the appearance for the support of claims which are not consistent with the conclusions of the Surgeon General and California EPA and convince me that these are just innocent mistakes. It has the clear appearance that SmokeFreeOhio is trying to mislead the public into thinking that there is strong scientific support for its claims when in fact, the science cited does not actually support these claims.

SmokeFreeOhio is running a campaign of deception, clear and simple. In my mind, this campaign of deception is irresponsible and unethical. I think that we in public health have a responsibility - an ethical responsibility - to accurately report the science to the public. SmokeFreeOhio is not only failing to do that, but they are misrepresenting the science in ways that are misleading the public.

As far as I'm concerned, the campaign battle over Issues 4 and 5 in Ohio is being fought with major deception on both sides.

If you want to see a battle in Ohio fought with any integrity, I'm afraid you'll have to wait until November 18, when the Wolverines head down to Columbus to take on Ohio State in a contest that will have national championship implications. And don't expect any trickery in that battle. Just in the trenches, hard-nosed, head-to-head football.

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