Thirdhand Smoke at Philip Morris

Thirdhand cigarette smoke is the fraction of cigarette smoke that remains in the environment long after a cigarette is extinguished. The Truth Tobacco Documents collection at UCSF was searched for information on thirdhand smoke. In 1991, scientists at Philip Morris Inc. conducted some of the first studies on thirdhand cigarette smoke. For 110 days, 8 hours a day, they ran sidestream cigarette smoke through a 30 m3 room that contained carpet, curtain and textured wallpaper. The room was ventilated with clean air every night. By comparing the chemicals in the air during the 8 hour smoking period and during the clean air ventilation period they showed that some smoke chemicals persist in the air 12 hours after smoking. By extracting the nicotine and nitrosamines from samples of the carpet, curtain and wallpaper, they found that high concentrations of nicotine and the carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) persisted in the room for over 50 days, that surface chemistry affected nitrosamine concentrations and that the concentration of NNK in the room, 110 days after the last cigarette was extinguished, could exceed the mass of NNK that entered the room as smoke. The authors concluded that these data, from a controlled environment where the total number of cigarettes smoked is known, provide further evidence that cigarette smoke chemicals remain in the environment for months after smoking, that they re-emit back into the air and that they react to form new toxins and carcinogens. Smokefree policies are the best method to reduce exposure to thirdhand smoke.

This unpublished, original research from Philip Morris Inc. demonstrates that majority of the nicotine and tobacco-specific nitrosamines in the secondhand smoke from each cigarette smoked indoors remains on indoor surfaces for months after the cigarette is extinguished. It also demonstrates that elevated concentrations of nicotine, ammonia, formaldehyde and the gas-phase nitrosamine, N-nitrosopyrrolidine, can be found in the air for over 12 hours after smoking, that surface chemistry affects nitrosamine formation and persistence and that the amount of the carcinogenic nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) that persists months after smoking ends can exceed the amount that actually came out of the cigarettes.

Authors: Whitlatch A, Schick S. ; Full Source: Nicotine & Tobacco Research. 2018 Jul 20. doi: 10.1093/ntr/nty153. [Epub ahead of print]