Absorption of nicotine and carbon monoxide from passive smoking under natural conditions of exposure.

Abstract

Seven nonsmokers were exposed to tobacco smoke under natural conditions for 2 h in a public house. Measures of nicotine and cotinine in plasma, saliva and urine and expired air CO all showed reliable increases. Concentrations of CO and nicotine after exposure averaged 15.7 and 7.5%, respectively, of the values found in heavy smokers. Although the increase in expired air CO of 5.9 ppm was similar to increases in smokers after a single cigarette, the amount of nicotine absorbed was between 1/10 and 1/3 of the amount taken in from 1 cigarette. Since this represented a realtively extreme acute natural exposure, any health risks of passive smoking probably depend less on quantitative factors than on qualitative differences between sidestream and mainstream smoke.