Study Suggests Thirdhand Smoke May Cause DNA Damage

Smoke-related chemical residues, known as thirdhand smoke, may cause damage to DNA in human cells, new research suggests. DNA damage is considered one of the first steps in the development of cancer.

Using laboratory tests, the researchers found a compound in smoke residue called tobacco-specific nitrosamine causes significant DNA damage, Fox News reports.

Thirdhand smoke remains on the clothes and hair of a person who has just smoked, or in the odor that lingers in hotel rooms where smokers have slept. The residue is absorbed in curtains and carpets, and remains on the surface of objects.

Scientists at Lawrence Berkeley National Laboratory in California studied thirdhand smoke by putting paper strips in smoking chambers. Some strips were in the chamber for only 20 minutes, while others were left for almost 200 days in a chamber that was ventilated. They extracted chemicals from the strips, and exposed cells to those chemicals. The chemical compounds in samples from the strips that were exposed over long periods had a higher concentration of thirdhand smoke, and more DNA damage, compared with the samples that came from strips that were only briefly exposed.

“Tobacco-specific nitrosamines, some of the chemical compounds in thirdhand smoke, are among the most potent carcinogens there are,” lead researcher Lara Gundel said in a news release. “They stay on surfaces, and when those surfaces are clothing or carpets, the danger to children is especially serious.”

The study is published in the journal Mutagenesis.

Thirdhand smoke is very difficult to get rid of, the researchers note. Previous research found it can be found in dust and surfaces of apartments more than two months after smokers have moved out. Vacuuming, wiping and ventilating don’t effectively lower contamination from nicotine, the news release notes. The best method to remove thirdhand smoke is to replace items that absorb the residue, such as carpeting, and to repaint.