Tobacco smoke is not limited to second hand smoke

Abstract

We read with interest “Thirdhand Smoke Exposure Induces Oxidative Damage, Initiates Skin Inflammatory Disease, and Adversely Alters the Human Plasma Proteome” by Sakamaki-Ching et al.,1 which is reported by the authors as the first clinical study identifying the molecular adverse health effects of third-hand smoke (THS) dermal exposure in humans. Tobacco smoke exposure is not limited to Second-Hand smoke (SHS), THS, known as the combination of gases and particles that, after having smoked, persist on surfaces, in dust or even on people's hair, skin and clothing.2,3 Until now, THS components were demonstrated to have damaging health effects, by being inhaled, ingested, and recently also was demonstrated that were even absorbed through the skin.1,2 Sakamaki-Ching et al. work provide urinary biomarkers and plasma proteomics pathway analysis of the effects of THS, demonstrating acute dermal THS exposure is not only harmful to humans, but also has the potential to initiate diseases. Although the study only included 10 individuals, it is enough to show that exposure to THS increases tobacco specific biomarkers (as cotinine) in urine, indicating the possible use of such biomarkers to objectively quantify THS exposure, in addition to self-reported information regarding tobacco exposure, and other biomarkers such as nicotine that accumulates on the hands.1 Moreover, according to Sakamaki-Ching et al. study, THS exposure alters human plasma proteome, initiates mechanisms of skin inflammatory disease, and elevates urinary biomarkers of oxidative harm, these harmful effects being similar to those of cigarette smoking.