Urinary acetonitrile concentrations correlate with recent smoking behaviour

OBJECTIVES: To assess the concentration of acetonitrile (a saturated aliphatic nitrile) in the urine of habitual cigarette smokers and non-smokers, as exposure to smoke can be measured by monitoring ambient air or by in vivo tests, but acetonitrile measured in exhaled breath is reportedly a quantitative marker of recent smoking behaviour. SUBJECTS AND METHODS: The study included 101 volunteers (57 men and 44 women, mean age 49 years). An absence of urinary tract infection on urine analysis or clinical history was mandatory. The subjects were classified into five groups, i.e. a control group of non-smokers and four groups according to the number of cigarettes smoked daily. Urine samples were stored at 8 degrees C until acetonitrile was measured, within 24 h of collection, using proton-transfer reaction mass spectrometry (PTR-MS). Each measurement was repeated at least 10 times, and the mean used for statistical analysis. RESULTS: The mean (sd) acetonitrile level in the urine of 46 non-smokers was 3.74 (1.78) parts per billion volatile (ppbv). The concentration of acetonitrile increased with the number of cigarettes smoked daily, the highest concentration being in the subgroup of 13 very heavy smokers (>30 cigarettes/day) with means up to 28.04 (5.38) ppbv. CONCLUSION: PTR-MS is a quick, noninvasive online method for determining urinary acetonitrile levels, a marker for recent active and passive smoking behaviour, and thus for checking compliance. As smoking has been shown to affect the genesis of bladder cancer, further studies are required to determine the association of acetonitrile with bladder cancer.