A new U.S. study, published in Environmental Science and Technology, warns against the risk of “thirdhand” smoke, which forms when particles from a cigarette seep into materials like hair, clothes and furniture.
Researchers at the Berkeley Lab in California carried out a series of experiments on humans and mice.
In one study, three volunteers who did not smoke were asked to wear the clothes of a heavy cigarette user for three hours.
Tests showed they had up to 86 times higher levels of the toxic compounds NNK and NNN in their urine after the experiment.
In another study, researchers exposed the same carcinogens to human lung tissue and showed they can cause DNA damage, which is one of the triggers of cancer.
“These findings illustrate the potential health impacts of thirdhand smoke, which contains not only TSNAs but hundreds of other chemicals, some of which are also known carcinogens,” said author Neal Benowitz, a medic at the University of California, San Francisco.
“Next steps for this research will explore in more detail the mechanisms of adverse health effects associated with tobacco and cannabis residues, effective remediation strategies and translation of scientific findings to tobacco control practice.”