Third-hand smoke can damage epithelial cells in the airways by straining cells and causing them to survive, a research team from the University of California at Riverside has found. The finding may help physicians treat patients who are exposed to third-party smoke.
"Our data show that human cells are affected by third-party smoke," said Prue Talbot, a professor at the Department of Molecular, Cell and Systems Biology, who led the research. "The health effects of THS have been studied in cultured cells and animal models, but this is the first study to show a direct impact of secondhand smoke on gene expression in humans."
The results of the study appear in JAMA Network Open . Third Hand Smoke (THS) occurs when smoke and smoke leaking from the tip of burning cigarettes settles on surfaces such as clothing, hair, furniture, and automobiles. THS is not pure smoking but refers to the residues of smoking.
"THS can return to the atmosphere and be undesirably inhaled by non-smokers," said Giovanna Pozuelos, the first author of the research report and a PhD student at Talbot's lab. "It has not been fully explored, which may explain why there are no rules for the protection of non-smokers."
Researchers received nasal scrapers from four healthy nonsmokers exposed to THS in a laboratory for three hours UC San Francisco. The UCR researchers then worked to extract high-quality RNA from the scrapes ̵
"THS inhalation for only three hours significantly altered gene expression in the nasal epithelium of healthy nonsmokers," Pozuelos said. "Inhaling changed the pathways associated with oxidative stress that can damage DNA, with cancer being a potential long-term result, and it is highly unlikely that exposure to THS for three hours would cause cancer, but if someone in an apartment or Living with THS or driving THS regularly in the car can have health implications. "
As nasal epithelial gene expression resembles bronchial epithelium, researchers note that their data are relevant to cells deeper in the respiratory system , In the samples studied, researchers also found that brief THS exposure influenced mitochondrial activity. Mitochondria are organelles that serve as cell power plants. If they were not checked, the observed effects would lead to cell death.
Pozuelos explained that the team focused on the nasal epithelium, as the nasal passage represents a way in which THS can enter the lungs of humans. The other common route of exposure is via the skin, which the researchers have not studied, but plan to do in the future.
Researchers are already working with groups in San Diego, California, and Cincinnati to investigate long-term exposure to THS, facilitated by access to homes where people are exposed to THS.
"Many people do not know what THS is," said Talbot, the director of the UCR's Stem Cell Center. "We hope that our study raises awareness of this potential health risk." Many smoking adults think: "I smoke outside so my family is not exposed in the house." But smokers carry chemicals like nicotine in their clothes It's important that people understand that THS is real and potentially harmful. "
Third-hand smoke increases the risk of lung cancer in mice
JAMA Network Open (2019). DOI: 10.1001 / jamanetworkopen.2019.6362
Scientists Find That Third-Hand Smoke Affects Human Cells (2019, June 28)
retrieved on June 29, 2019
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