Measuring the exposure of infants to tobacco smoke. Nicotine and cotinine in urine and saliva

Biochemical markers of smoke absorption and self reported exposure to passive smoking

One hundred non-smoking patients attending hospital outpatient clinics reported their degree of passive exposure to tobacco smoke over the preceding three days and provided samples of blood, expired air, saliva, and urine. Although the absolute levels were low, the concentration of cotinine in all body compartments surveyed was systematically related to self reported exposure. Salivary nicotine concentration also showed a linear increase with degree of reported exposure, although this measure was sensitive only to exposure on the day of testing. Measures of carbon monoxide, thiocyanate, and plasma nicotine concentrations were unrelated to exposure. The data indicate that cotinine provides a valid marker of the dose received from passive smoke exposure. The non-invasive samples of urine and saliva are particularly suited to epidemiological investigations. Detailed questionnaire items may also give valuable information.

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.