Researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) identified thirdhand smoke, the toxic residues that linger on indoor surfaces and in dust long after a cigarette has been extinguished, as a health hazard nearly 10 years ago. Now a new study has found that it also increases lung cancer risk in mice. These studies indicated that thirdhand smoke exposure induced DNA double-strand breaks and increased cell proliferation and colony formation. In addition, RNA sequencing analysis revealed that thirdhand smoke exposure caused endoplasmic reticulum stress and activated p53 (tumor suppressor) signaling.
Field studies in the U.S. and China have confirmed that the presence of thirdhand smoke in indoor environments is widespread, and traditional cleaning methods are not effective at removing it. Because exposure to thirdhand smoke can occur via inhalation, ingestion, or uptake through the skin, young children who crawl and put objects in their mouths are more likely to come in contact with contaminated surfaces, and are therefore the most vulnerable to thirdhand smoke’s harmful effects.
— source newscenter.lbl.gov