Health effects of passive smoking in adults

The inhalation of smoke exhaled by a smoker, second-hand smoke (SHS), environmental smoke or the smoke produced at the lit end of smoked tobacco (sidestream smoke) by the act of smoking is referred to as passive smoking. These inhaled products of tobacco combustion have been shown to have detrimental effects on most organs in the body. Assessment of exposure is measured by a number of direct and indirect methods, which include measurement of air nicotine and the measurement of small particles (<2.5 μm) in air. Cotinine, the main breakdown product of tobacco, is measured in body fluids as well as self-report and observed exposure measurements. The adverse health effects were largely established by large-scale epidemiological studies carried out over many years. The finding that SHS caused lung cancer led the International Agency for Research on Cancer to declare SHS as a class A carcinogen. The health benefits of smoke-free legislation have been observed all over the world and corroborate the predictions from known health effects of exposure to SHS and seem to be even greater than expected. A further side effect of smoke-free legislation is a major contribution to the denormalisation of smoking in public to which electronic cigarettes are perceived as a possible threat. The extension of smoke-free legislation to other areas as well as indoor public spaces has started and is under consideration in many countries.