Third-hand smoke damages human cells  

美国华人科学家主导研究发现三手烟损害人体基因

Hang Bo, a chief researcher at Lawrence Berkeley National Laboratory.[Photo provided by Hang to CNS]

San Francisco (CNS) -- Third-hand cigarette smoke residue that clings to surfaces even after the smoke has cleared out can cause DNA damage in human cells, according to a new study led by a Chinese American scientist.

Hang Bo, chief researcher at Lawrence Berkeley National Laboratory, conducted a study with colleagues on third-hand smoke and published the results in the journal Mutagenesis.

Hang said Wednesday that third-hand smoke is tobacco smoke contamination that remains after the cigarette has been extinguished.

Tobacco-specific nitrosamines, some of the chemical compounds in third-hand smoke, are among the most potent carcinogens, he said, adding that the toxins that linger in carpets, sofas, clothes and other materials hours or even days after a cigarette is put out is a health hazard, especially for infants and children.

Exposure to third-hand smoke led to both the deterioration of DNA strands and the oxidation of DNA. This in turn led to gene mutation, which has been linked to various diseases including cancer, Hang said.

The only way to get rid of the toxins is to change the polluted furniture, carpets and wall panels, he said.

A secondhand car with heavy smoke is 10 percent cheaper, as more people have realized the hazards of third-hand smoke, he said.