It doesn’t matter how we are exposed: Coming in contact with cigarette smoke, whether through first, second-, or thirdhand smoke exposure, harms all parts of human health, including our DNA. A study led by Dr. Li Wang at the North Sichuan Medical College in Nanchong, China, looked at how cigarette smoke extract, which is a liquid containing the chemicals in tobacco smoke, damages cells and can cause cancer.
The researchers had two groups of human lung cells. They exposed the first group to cigarette smoke extract by growing the cells in a culture containing the extract, but they did not expose the second group. The extract damaged the cells’ DNA in the first group, which caused the cells to reproduce uncontrollably and form tumors. These tumors became cancerous and grew larger than tumors made from the second group of cells.
While cigarette smoke extract is not identical to thirdhand smoke residue, it contains many of the same chemical compounds. This study shows that exposure to those toxic chemicals can damage human cells and DNA.
Further, Wang’s results with cigarette smoke extract are consistent with several studies that examined DNA function following thirdhand smoke exposure. Many of these studies were conducted by Thirdhand Smoke Consortium researchers, including by Drs. Peyton Jacob III, Antoine Snijders, Jian-Hua Mao, and Suzaynn Schick. For example, two studies found thirdhand smoke exposure to damage lung cells (study 1; study 2). Another found inhaling thirdhand smoke to damage DNA in nasal cells. Rather than using cigarette smoke extract, these studies used thirdhand smoke residue that was generated in Dr. Schick’s smoking chamber, a core resource of the Collaborative Research Consortium.
These and additional studies highlight how tobacco smoke chemicals in all forms damage DNA. The best way to protect yourself and others from the toxic chemicals in tobacco smoke is to avoid places where people have smoked and to not allow smoking in your home or vehicle.
Click here to read the research study.
