The chemical memory of smoking tobacco.

The concentration in urine of N -acetyl-hydroxy-propyl-cisteine (3HPMA), an acrolein metabolite, has been employed as a marker of the risk of illness of smokers and the relative concentration of creatinine has been evaluated to verify the effect of moving from the practice of burning tobacco to nicotine vaping. From the results concerning the urine samples of 38 subjects, collected from 2021 to 2023 and analyzed by LC-MS/MS, corresponding to 5 active smokers, 13 previously heavy smokers who replaced traditional tobacco by vaping, and 20 non-smokers, a dramatic reduction was found in 3HPMA/creatinine in urine. 3HPMA varied from values of 2150-3100 μg g creatinine -1 to levels of 225-625 μg g creatinine -1 found for non-smokers, with the time decay described by the equation y = 0.3661 x 2 - 94.359 x + 6246.4 ( R 2 : 0.757), providing a time of approximately 10 years for tobacco memory after the cessation of the consumption of burned tobacco.