The new finding has implications since nicotine is classified as a toxic substance (nicotine is used as a pesticide). The absorption via the skin is either direct from smoke or via smoke being absorbed into clothes. The finding therefore has additional consequences for secondary smoking (or ‘passive smoking’) where a non-smoker is at risk from the activities of the smoker.
In addition, the smoke particles have been shown to remain in a closed environment (like a room with the windows closed) for several hours, thereby providing opportunities for some particles to be absorbed through the skin and into the blood stream.
The finding not only applies to the smoking of pipes and conventional cigarettes, but also to e-cigarettes. As well as highlighting this, the research raises particular concerns in relation to children, who are at particular risk due to their brains still undergoing development.
While the results are interesting, the study was undertaken using a very small sample. For the study, two non-smoking men spent three hours in a room filled with tobacco smoke. The exposure levels were designed to simulate a nightclub (while most nightclubs do not allow traditional tobacco products, many allow e-cigarettes). The men wore masks connected to cylinder so they could breathe in cleaner air. The skin of the men was subject to testing.
The study showed the men absorbed about 570 micrograms of nicotine through their skin (from blood tests). This was the equivalent of smoking up to six cigarettes. Absorption was shown through clothes as well as through bare skin.
Discussing the findings with Science News, Dr. Gabriel Bekö, who led the research from Technical University of Denmark in Lyngby, said: “The way we are exposed to secondhand smoking is not as simple as we had thought.” Further research will be required to confirm the findings using a wider pool of subjects.
The research findings are published in the journal Indoor Air. The research paper is titled “Measurements of dermal uptake of nicotine directly from air and clothing.”