Tobacco sidestream smoke: uptake by nonsmokers.

Some epidemiological studies indicate an association between passive smoking and an increased risk for cancer, especially for cancer of the lung. Other reports, however, have failed to confirm these findings. Biochemical analyses of the physiological fluids for markers of exposure to tobacco smoke are needed as measurements of the uptake of smoke components by nonsmokers and for the estimation of relative cancer risk to passively exposed persons compared with that to active cigarette smokers. This communication reports the uptake of carbon monoxide, hydrogen cyanide, and nicotine after passive smoke exposure under controlled conditions. The results indicate that salivary nicotine values reflect the level of recent passive smoke exposure within an hour and that urinary cotinine values indicate the level of passive smoke exposure in the preceding hours. N-Nitrosoproline has been shown to serve as an indicator of endogenous N-nitrosamine formation in cigarette smokers: yet, preliminary studies do not indicate that urinary excretion of N-nitrosoproline is increased following short-term passive smoke exposure. In infants, first field studies suggest a correlation between exposure to tobacco-smoke-polluted environments and levels of cotinine in both serum and urine.