Smoking is injurious to health. That’s common knowledge now. But smoking doesn’t just affect the person who smokes but also the people around them. According to research carried out by scientists at the University of California, Riverside, thirdhand smoke can damage epithelial cells in the respiratory system. The study also mentioned this happen due to the stress callused on the cells and forcing them to fight for survival.
"Our data show that cells in humans are affected by thirdhand smoke," said Prue Talbot, a professor in 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 effect of thirdhand smoke on gene expression in humans."
Thirdhand smoke or THS means the chemical residue of tobacco smoke contamination that clings to clothing, wall, furniture, carpet, cushions, hair, skin and other materials after the cigarette is extinguished. "THS can resurface into the atmosphere and can be inhaled unwillingly by nonsmokers," said Giovanna Pozuelos, the first author of the research paper and a graduate student in Talbot's lab. "It has not been widely studied, which may explain why no regulations are in place to protect nonsmokers from it."
The research team obtained the results by obtaining nasal scrapes from four healthy nonsmokers exposed toTHS for three hours in a laboratory setting. They found 382 genes were significantly over-expressed; seven other genes were under-expressed. They then identified pathways affected by these genes.
"THS inhalation for only three hours significantly altered gene expression in the nasal epithelium of healthy nonsmokers," Pozuelos said. "The inhalation altered pathways associated with oxidative stress, which can damage DNA, with cancer being a potential long-term outcome. It's extremely unlikely a three-hour exposure to THS would cause cancer, but if someone lived in an apartment or home with THS or drove a car regularly where THS was present, there could be health consequences."
The research team noted that many are unaware of THS and the harsh effects it has on people’s health. They hope their research study raises awareness of this potential health hazard. Many smoking adults think, 'I smoke outside, so my family inside the house will not get exposed.' But smokers carry chemicals like nicotine indoors with their clothes. It's important that people understand that THS is real and potentially harmful."
Study results appear in JAMA Network Open.
