Researchers at the University of California and published in eBioMedicine of The Lancet Family of Journals revealed that acute exposure of the skin to THS (third hand smoke) elevates biomarkers associated with the initiation of skin diseases such as contact dermatitis and psoriasis.

In the clinical trial that took place at UC San Francisco, 10 healthy, non-smoking participants were enrolled who were 22 to 45 years old. During the study duration, each participant wore clothing impregnated with THS for three hours and walked or ran on a treadmill for at least 15 minutes each hour to induce perspiration and increase the uptake of THS through the skin. Blood and urine samples were then collected from the participants at regular intervals to identify protein changes and markers of oxidative stress induced by the THS.

The blood and urine analysis of the participants revealed that acute THS exposure led to the elevation of urinary biomarkers of oxidative damage to DNA, lipids, and proteins, and these biomarkers remained high after the exposure stopped.

Dr. Prue Talbot, a professor of cell biology, explained that the skin is the largest organ to contact THS and may thus receive the greatest exposure. He added that if a person buys a used car previously owned by a smoker, that person is putting himself at some health risk. The same applies to staying in a hotel room that a smoker previously occupied. He added that the findings of the study underscore the idea that dermal exposure to THS could lead to the molecular initiation of inflammation-induced skin diseases. 

(Source: https://www.hindustantimes.com/lifestyle/health/residual-pollutants-in-air-and-dust-after-smoking-tobacco-can-cause-inflammatory-skin-diseases-research-101665909480042.html )