According to a recent UCLA study, "Environmental Tobacco Smoke and Tobacco-Related Mortality in a Prospective Study of Californians" (reported in the British Medical Journal), environmental tobacco smoke (ETS) is not as harmful as many anti-smoking activists say. The study, which tracked 118,058 individuals over the course of thirty-eight years, found no significant correlation between exposure to secondhand smoke and death due to coronary heart disease or lung cancer. There was a correlation between secondhand smoke and chronic obstructive pulmonary disease, which was more likely to kill spouses of smokers.
It has been well established that coronary heart disease, lung cancer, and chronic obstructive pulmonary disease (including chronic bronchitis and emphysema) are closely linked to active smoking. The UCLA study does not dispute these facts. However, there is considerable controversy over whether secondhand smoke bears on one's likelihood of developing these diseases.
The UCLA study, co authored by James Enstrom and Geoffrey Kabat, followed the spouses of smokers and non-smokers and recorded the level of environmental tobacco smoke to which spouses of smokers were subject. The research tracked a broad cross-section of individuals; persons of different ages, races, education levels, and body mass were included. To standardize their findings, the researchers controlled for these confounding and influential factors. Enstrom and Kabat discovered that spouses exposed to secondhand smoke were about as likely as those not exposed to secondhand smoke to die from heart disease and lung cancer.
Many were quick to find fault with the study because it was funded in part by tobacco companies but even critics who focus on the funding should note that the study was initiated by the American Cancer Society and its continuation funded by money collected through California Proposition 99's cigarette surtax program. Finally, the study's findings are consistent with those of the CDC and other epidemiological ETS research as well as with ACSH's own past report on ETS, which noted that while ETS has negative effects such as increased ear infections in chronically exposed children it is not a significant risk factor for developing coronary heart disease or lung cancer.
Ultimately, the study does not exonerate tobacco companies, but it strikes a blow at the public's misperception of the ill effects of secondhand tobacco smoke and does so shortly after New York City mayor Michael Bloomberg's creation of a ban on smoking in restaurants and bars, based largely on purportedly life-threatening health hazards to employees. The study suggests that the public's fears and politicians' ideas about how we are affected by ETS may be misguided. Though secondhand smoke places one at risk for respiratory ailments, and is especially hazardous to the health of children, it is not a major factor in the development of coronary heart disease or lung cancer.
To learn about the full range of negative effects that being a smoker oneself has, see ACSH's newly-updated book Cigarettes: What the Warning Label Doesn't Tell You.