Anti-Smoking Group Claims that Secondhand Smoke Causes Emphysema; Perhaps Most Fallacious of All Anti-Smoking Claims to Date

A supposed "fact sheet" put out by SmokeFreeOhio claims that secondhand smoke causes the debilitating lung disease known as pulmonary emphysema.

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

The Rest of the Story

There is not sufficient evidence to support the claim that secondhand smoke causes emphysema. Even the Surgeon General, in his comprehensive report on secondhand smoke, failed to conclude that there is a causal relationship between secondhand smoke exposure and chronic obstructive lung disease.

Most worrisome to me is that the SmokeFreeOhio claim comes in association with an apparent response to address comments I made 7 months ago about fallacious claims in SmokeFreeOhio's secondhand smoke "fact sheet." Why is this worrisome? Because it suggests that SmokeFreeOhio was paying careful attention to the details of the fact sheet, and that this was not some sort of careless, quickshod attempt to throw a fact sheet together.

In fact, SmokeFreeOhio did eliminate four of the fallacious claims that I pointed out in my March 2006 post about the scientific misrepresentations in their fact sheet. Unfortunately, in deleting these claims, the anti-smoking group has added a number of new fallacious claims, and retained two of the old ones.

This is troublesome to me, because it argues against one of the possible explanations for this inaccurate claim: that SmokeFreeOhio was just being very careless and threw this together without reviewing it. In contrast, it appears that SmokeFreeOhio paid great attention to the fact sheet, altering it to address the concerns I expressed, probably with the knowledge that the fact sheet would be under great scrutiny, as they knew that I had blogged the inaccuracies in the original version of the document.

So I'm left to conclude that this is either a deliberate attempt to pull the wool over the eyes of the public and make them think that secondhand smoke is a lot more hazardous than it actually has been proven to be, or it is scientific shoddiness that casts a dark cloud on the scientific credibility of the entire anti-smoking movement.

What is the support that SmokeFreeOhio provides to back up its claim that secondhand smoke causes emphysema? They cite one article: a 2003 study by Carnevali et al., published in the American Journal of Physiology, and entitled "Cigarette smoke extract induces oxidative stress and apoptosis in human lung fibroblasts."

You've got to be kidding me! They are taking this one study, an in-vitro study showing that cigarette smoke extract causes oxidative stress in cultured human fibroblast cells, and they conclude, therefore, that secondhand smoke causes emphysema.

The authors of the paper itself merely speculate that this may be a mechanism by which active smoking causes emphysema: "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."

The California Environmental Protection Agency report on secondhand smoke, which is probably the most comprehensive review of the subject and which drew the controversial (even within the tobacco control community) conclusion that secondhand smoke causes breast cancer, did not even suggest that secondhand smoke causes pulmonary emphysema in nonsmokers.

In fact, the report stated that any effects of secondhand smoke on chronic lung function in nonsmokers are limited to small decrements in lung function, and is mainly in the form of exacerbating symptoms of patients with existing chronic lung disease:

"While lung function effects are less pronounced in adults than in children, ETS exposure appears to play a role in the genesis of chronic lower respiratory tract symptoms in otherwise healthy individuals and produces small, but measurable, decrements in pulmonary function. In adults, exposure to ETS at home and/or work was less associated with the onset of respiratory illness but rather with the aggravation of the symptoms and severity of existing bronchitis, sinusitis and emphysema. Among adult nonsmokers exposed to ETS, eye, nose and throat irritation, as well as odor annoyance, are the most commonly reported health complaints. These complaints occur at levels near or overlapping the odor threshold for ETS, making their prevention technically difficult in smoking-permitted buildings."

This essentially concludes that secondhand smoke does not cause emphysema in nonsmokers.

The Surgeon General, in his comprehensive report on secondhand smoke, also fails to conclude that secondhand smoke is a cause of emphysema. He mentions that there is suggestive evidence, but it is not adequate enough to support a causal conclusion at this time:

"The evidence is suggestive but not sufficient to infer a causal relationship between secondhand smoke exposure and risk for chronic obstructive pulmonary disease."

What is ironic about SmokeFreeOhio making this claim to the public is that this is the organization that has been blasting its opponent in a Ohio dueling ballot initiative contest for misleading the public!

I'm afraid SmokeFreeOhio has no business accusing anyone else of misleading the public. At least until they do some housekeeping and apologizing of their own.

Frankly, it is amazing to me how scientific claims made by anti-smoking groups continue to get more and more shoddy.

I fear this presents a severe problem for the anti-smoking movement. Our credibility is truly at stake. You just can't continue to make ridiculous and completely unsupported claims like this and expect that anyone is going to take you seriously.

But most disturbing to me is that we don't seem to be taking ourselves seriously. We don't seem to care about what is becoming an alarming lack of scientific integrity in the movement.

We're the ones who attack the tobacco companies incessantly for misleading the public and making unsubstantiated health claims. You'd think we would want to do a little better than this.