A study conducted by the University of California, Riverside, found that skin exposure to nicotine concentrations resulting from "third-hand smoke" (THS) and leaks from electronic cigarettes may harm the skin. The term "third-hand smoke," in which nicotine is a key element, refers to the smoke and odors that remain in smoking areas, meaning the accumulation of smoke emitted from burning cigarettes on surfaces such as clothes, hair, furniture, and cars. Thus, "third-hand smoke" (THS) indicates the residues left by smoking. Leaks from electronic cigarettes refer to the electronic liquid leaks that may occur due to the spillage of electronic cigarette products or when consumers and vendors mix refillable electronic cigarette liquids.
The study's findings in the air show: Giovanna Boswellos, who graduated earlier this year from the University of California Riverside with a PhD in cellular, molecular, and developmental biology, stated, "We found that skin contact with nicotine may impair wound healing, increase susceptibility to skin infections due to reduced immune response, and cause oxidative stress in skin cells." The study was conducted using EpiDermTM, a three-dimensional model of human skin, and cultured human keratinocyte cells. Keratinocytes are the skin cells that produce keratin, the protein found in hair and nails.
Researchers exposed EpiDermTM for 24 hours to different concentrations of nicotine typically found in "third-hand smoke" environments and leaks from electronic cigarettes. They then proceeded to identify the processes and pathways altered due to exposure. They studied the effect of nicotine on cellular organelles and mitochondria and peroxisomes, which are organelles containing enzymes involved in various metabolic reactions. According to Boswellos, individuals most at risk are those suffering from skin diseases such as diabetes-related ulcers or arterial ulcers. She said, "Skin contact with nicotine residues may impair healing from such skin lesions and increase susceptibility to pathogenic skin infections. Young children and infants, who tend to crawl on contaminated surfaces or frequently come into contact with indoor surfaces, are particularly at risk for severe skin exposure. Workers in highly contaminated environments with third-hand smoke, where smoking is allowed indoors for months or even years, can also be exposed."
Fortunately, the changes in the mitochondria of keratinocyte cells exposed to nicotine for 24 hours are reversible. Co-author Bro Talbot, a co-professor of cell biology in the study, said, "The skin may recover by avoiding continuous skin exposure to third-hand smoke contaminated environments and properly handling fluids used in electronic cigarettes." He added, "It is important to note that relatively short exposure, 24 hours in our study, is enough to cause skin damage." Boswellos emphasized that the severity of skin damage depends on both the duration of exposure and the concentration of nicotine. She explained: "Both third-hand smoke leaks and electronic cigarettes and leaks can be harmful. Chronic exposure to third-hand smoke may occur for someone living in a home contaminated with these accumulations, which may lead to continuous skin exposure. Vendors and consumers who handle electronic cigarettes with high concentrations of nicotine or use them may also be exposed."
Boswellos advises consumers and vendors working with electronic cigarettes to reduce skin contact by wearing appropriate protective gear and properly cleaning contaminated areas. She said, "Restrictions on indoor smoking and electronic smoking should be implemented, along with policies for managing contaminated environments."
