Has the health effect of passive smoking been overstated?
The link between environmental tobacco smoke and coronary heart disease and lung cancer may be considerably weaker than generally believed, conclude James Enstrom of the University of California, Los Angeles and Geoffrey Kabat of New Rochelle, New York, in this week’s BMJ.
This study will add to the already controversial debate on the health impact of passive smoking.
Their analysis involved 118,094 California adults enrolled in the American Cancer Society cancer prevention study in 1959, who were followed until 1998. Particular focus was on the 35,561 never smokers who had a spouse in the study with known smoking habits.
The authors found that exposure to environmental tobacco smoke, as estimated by smoking in spouses, was not significantly associated with death from coronary heart disease or lung cancer at any time or at any level of exposure. As expected, active cigarette smoking was confirmed as a strong, dose related risk factor for coronary heart disease, lung cancer, and chronic obstructive pulmonary disease.
These findings suggest that environmental tobacco smoke could not plausibly cause a 30% increased risk of coronary heart disease, as is generally believed, although a small effect cannot be ruled out, say the authors.
Despite some limitations, this large study has several important strengths, add the authors. As such, it seems premature to conclude that environmental tobacco smoke causes death from coronary heart disease and lung cancer.
The impact of environmental tobacco smoke on health remains under dispute, writes Professor George Davey Smith in an accompanying editorial. He points to several difficulties in studies of passive smoking, such as problems with measurement imprecision, misclassification, confounding factors, and low statistical power, that can lead to the risks being distorted.
Despite suggesting that passive smoking is associated with an increased risk of respiratory disease, the study will be promoted as showing that the detrimental effect of passive smoking has been overstated, he concludes.
All latest news from the category: Health and Medicine
This subject area encompasses research and studies in the field of human medicine.
Among the wide-ranging list of topics covered here are anesthesiology, anatomy, surgery, human genetics, hygiene and environmental medicine, internal medicine, neurology, pharmacology, physiology, urology and dental medicine.
A mysterious blue molecule will help make better use of light energy
Researchers at IOCB Prague are the first to describe the causes of the behavior of one of the fundamental aromatic molecules, which fascinates the scientific world not only with its…
Let it flow: recreating water flow for virtual reality
The physical laws of everyday water flow were established two centuries ago. However, scientists today struggle to simulate disrupted water flow virtually, e.g., when a hand or object alters its…