Passive smoking at the workplace: Health risk or not?

Abstract

Passively inhaled tobacco-smoke contains numerous toxic, cancerogenic and cocancerogenic volatile substances. Quantitative determinations of compounds present in the room-air of restaurants and bureaus make it possible to evaluate the exposure of persons to tobacco-smoke at the working place. By comparing main- with sidestream-smoke, 50 to 100 times higher concentrations of the latter have been found. Even a considerable dilution of sidestream-smoke in the room-air does not prevent the passive smoker from inhaling volatile compounds, such as formaldehyde, NO(x) and some nitrosamines, during one hour, in amounts which are comparable with those which the active smoker draws into the lungs when smoking several cigarettes. Less volatile substances, like nicotine and acroleine as well as particulate compounds, such as polyaromatic hydrocarbons, and pyrolysis-products reach levels in passively inhaled tobacco-smoke only one tenth to one hundredth of those in the actively inspired cigarette-smoke. They are too low for being a risk for the passive smoker. Nicotine and its metabolite cotinine have been detected in body fluids of passive smokers, indicating the systematic availability of constituents present in passively inhaled tobacco-smoke. The cancerogenic action of cigarette-smoke was confirmed in animal experiments. Sidestream-smoke is more toxic and probably more cancerogenic than mainstream-smoke of cigarettes. Epidemiological observations which found a significantly increased lung cancer risk of the passive smoker clearly exceed those which did not indicate differences. It is not justified any more to deny any causal relationship between passive smoke and lung cancer.