Truth about Second-hand Smoke

By Michael Fumento


Copyright 1997 Michael Fumento

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Anytime you see an article or book title beginning "The Truth About . . ." your hornswoggling radar should go up. The January Consumer Reports (CR) cover story, "The Truth about Secondhand Smoke," currently being circulated by the American Medical Association, is a good example of why.

This alleged truth nonetheless falsely maligned an article in Investor’s Business Daily (IBD) from two years earlier which indicated that the EPA’s report declaring secondhand, or passive smoke, a carcinogen used shoddy science.

All the scientists quoted in the IBD article to back up this viewpoint have received some type of industry support," said the CR piece, which appeared anonymously but was written by assistant editor Nancy Pappas.

Actually, two scientists in the article who criticized the EPA’s statistical analysis have never received tobacco money, but rather have done studies linking active smoking to harm in adults and fetuses. A third has received more consulting funds from tobacco opponents than he ever did from tobacco companies. All are highly respected in their fields, and hardly the type to sell out or 200 pieces of silver. No matter, said CR, they are all dupes of Big Tobacco.

CR also didn’t say that several of the scientists it cites have received substantial amounts of money from the anti-tobacco lobby. In fairness, though, the article probably needed to fall back on smearing, since its scientific analysis was so wanting.

Consider how it dealt with meta-analysis, the pooling of results of numerous studies which by themselves are too small to be definitive. Meta-analysis is controversial because inevitably it mixes studies done by different researchers under different conditions. Like oil and water, they can be thrown together but not really combined. Further, good epidemiology builds on studies that have gone before. Meta-analysis wipes this out, because it weighs the first study as heavily as the last.

CR ignored the weighing issue. As for inability to mix studies, it claimed that the EPA overcame this by combining studies only on a geographic basis. That is, it combined all American studies together, instead of lumping in other countries. That’s a logical fallacy called a non-sequitur; it doesn’t follow. It’s like saying, "Well, of course the report was fair. After all, it was released on a Tuesday."

CR also pooh-poohed the disturbing fact that the EPA changed the traditional confidence interval, the method used to measure the possibility that the findings were just by chance. The EPA has never given a satisfactory explanation for the change. It has said that such an analysis is allowed when there is no evidence that the suspected carcinogen could have any sort of protective effect. Yet one published study from China did show a protective effect.

Most importantly, CR never told its hapless readers that using such a slight increase in risk as the EPA meta-analysis found, 119 lung cancers where 100 would be expected (expressed as 1.19), to declare something a carcinogen is unprecedented.

In a recent medical journal editorial accompanying a study linking breast cancer and induced abortion, Lynn Rosenberg of the Boston University School of Medicine stated, "Differences in risk of 50 percent (relative risk 1.5) is small in epidemiological terms and severely challenges our ability to distinguish whether it reflects cause and effect or whether it simply reflects bias."

The issue of passive smoking often induces passive thinking.

The American Cancer Society’s Eugenia Calle told one newspaper, "Epidemiological studies in general are not able, realistically, to identify with any confidence any relative risks lower than 1.3. In that context, the 1.5 is a modest elevation compared to some other risk factors that we know cause disease."

Meanwhile, the National Cancer Institute declared, "relative risks of less than two are considered small and are usually difficult to interpret. Such increases may be due to chance, statistical bias, or effect of confounding factors that are sometimes not evident."

Strange that a 1.19 should be enough to classify second-hand tobacco smoke as a Class A carcinogen, but a 1.5 or even 2.0 probably is too low to mean anything.

The Cancer Institute’s statement makes sense. There are too many difficult or even impossible-to-measure possible confounders. One, which CR brings up, is diet. It then refutes it citing, yes, the EPA report. So doing, it ignored a December, 1993 article in the prestigious Journal of the National Cancer Institute. This study, while finding no link between passive smoking and lung cancer in women, did find that the women with the highest saturated fat consumption had six times the lung cancer rate of women with the lowest level.

Other studies have established that women who live with husbands who smoke have a significantly greater fat intake than other women. The correlation is that people who smoke tend to be in the lower economic class and these people also tend to eat poorer diets.

None of this proves that passive smoking is not harmful. What it does mean is that if there is a risk, it is probably too small to be measured.

So why the tirade against passive smoking, even to the point of the (deservedly) respected AMA sending out shoddy Consumer Reports articles? Because apparently the AMA, like the EPA, has decided that the harm done by active smoking is so serious that the use of any tool to combat it is justified, even if it means crummy science and false representation.

Oh, and add the federal Centers for Disease Control and Prevention to the list. In December one CDC official cited passive smoking to help explain an increase in asthma over the last decade. That’s curious, because even as the number of asthma sufferers was rapidly increasing, the number of cigarette smokers was rapidly going down.


Read Michael Fumento’s additional work on smoking, on the EPA, and on cancer.