Stoking the rigged terror of secondhand smoke: the "science" behind the surgeon general's latest report on secondhand smoke does not support officials' claims.

• Author: Gori, Gio Batta

While there is agreement that smoking cigarettes, like most pleasures, is risky, the zealous people who wish to abolish smoking could not have mounted the current antismoking crusade without playing up the risks of so-called "secondhand smoke"--or, what the scientific literature calls environmental tobacco smoke (ETS). Under the flag that the end justifies the means, the purported risks posed by ETS have been used to justify draconian regulations that criminalize and marginalize lawful citizens, pitting children against parents, spouses against spouses, and people against people to the point of raising homicidal animosities against smokers.

Last July, the U.S. surgeon general released its latest report on ETS, The Health Consequences of Involuntary Exposure to Tobacco Smoke. As usual, it is not a primary study but a summary of selected previous studies. The report shows once again the antismoking crusaders' successful seizure of the surgeon general's authority, much as it happened for previous ETS reports issued by the U.S. National Academy of Sciences, the Environmental Protection Agency, the World Health Organization, the UK Royal College of Physicians, and other authorities.

At the press conference introducing the report, then-surgeon general Richard Carmona personally ventured the absurd assertions that "there is no risk-free level of secondhand smoke exposure," that "breathing secondhand smoke for even a short time can damage cells and set the cancer process in motion," and that, for children exposed to secondhand smoke, "eventually, they'll develop cardiovascular disease and cancers over time."

Of course, without the time to analyze the studies themselves, the surgeon general has to trust what words others put in his report. Yet, on careful reading, those horrific claims are not supported by the studies reviewed in the report, even on assuming that the studies might be trustworthy.

FATAL FLAWS

Claimed ETS risks are reported with a precision of two decimal points--1.21 for lung cancer, according to the latest surgeon general's report. Such a precise assessments of risk, or of anything else for the matter, must fulfill some careful, analytical requirements. First, care must be taken to ensure that what is measured is, indeed, what is claimed to be measured. Second, measurements must be accurate within an explicit margin of error. Third, the results cannot be explained by alternatives. And finally, repeated studies should yield consistent, reproducible results. Such are not only the requirements of scientific observations, but of commonsense evidence as well.

In assessing BTS risk, studies would have to compare groups of nonsmokers that had been either exposed or not exposed to ETS. Yet, persons with no prior exposure to ETS are virtually impossible to find, and it is only possible to utilize nonsmokers who have been more or less exposed.

Simply having been exposed to ETS could not be the basis of risk estimates, however. Risk could only be determined in relation to the biologically effective doses that people internalize, as the surgeon general report confirms. Such doses cannot be derived from exposure data without knowing the simultaneous rates of individual inhalation and metabolic transformations.

Effectively, those rates cannot be measured and cannot be known because they vary continuously and independently from location to location, moment to moment, day to day, year to year. The changes are rapid and chaotic, and make it impossible to obtain cumulative measures over time. The recent surgeon general's report avoids any discussion of this issue, with the tacit admission that the absolutely crucial measurements of biologically effective doses are impossible--an admission that is alone sufficient to disqualify any representation of the small risks claimed.

Indifferent to this capital impediment, the surgeon general's report keeps insisting on exposure as a determinant of risk, despite describing in some detail the many insurmountable obstacles to...