Thirdhand smoke, or THS, comprises the residual pollutants from tobacco smoke that remain on surfaces and in dust after tobacco has been smoked. It can remain on indoor surfaces indefinitely, causing potentially harmful exposure to both smokers and non-smokers.
Researchers have found that acute exposure of the skin to THS elevated biomarkers is associated with the initiation of skin diseases, such as contact dermatitis and psoriasis.
The clinical investigation involved the participation of 10 healthy, non-smokers who were 22 to 45 years old. For three hours, each participant wore clothing impregnated with THS and either walked or ran on a treadmill for at least 15 minutes each hour to induce perspiration and increase 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.
“We found acute THS exposure caused elevation of urinary biomarkers of oxidative damage to DNA, lipids, and proteins, and these biomarkers remained high after the exposure stopped,” said Sakamaki-Ching, a research scientist. “Cigarette smokers show the same elevation in these biomarkers. Our findings can help physicians in diagnosing patients exposed to THS and help develop regulatory policies dealing with remediation of indoor environments contaminated with THS.”
The THS exposures that the 10 participants were subjected to were relatively brief and did not cause visible changes in the skin. Nevertheless, the molecular biomarkers in blood that are associated with early-stage activation of contact dermatitis, psoriasis and other skin conditions were elevated.
“This underscores the idea that dermal exposure to THS could lead to molecular initiation of inflammation-induced skin diseases,” Sakamaki-Ching said.
Next, the researchers plan to evaluate residues left by electronic cigarettes that can come into contact with human skin.
Shane Sakamaki-Ching, Suzaynn Schick, Gabriela Grigorean, Jun Li, Prue Talbot. Dermal thirdhand smoke exposure induces oxidative damage, initiates skin inflammatory markers, and adversely alters the human plasma proteome. eBioMedicine, 2022; 84: 104256 DOI: 10.1016/j.ebiom.2022.104256
University of California – Riverside. “Thirdhand smoke can trigger skin diseases, study finds: Clinical study advances molecular understanding of THS effects on skin.” ScienceDaily. ScienceDaily, 11 October 2022. <www.sciencedaily.com/releases/2022/10/221011161308.htm>.
Photo by Reza Mehrad