Smoking and the spread of cigarette smoke in an apartment entails more dangerous and long-term health consequences for residents than previously thought. Plaque, which even after airing remains on absolutely all surfaces, has a genotoxic effect, according to a study conducted by experts from leading research centers in the United States. It contributes to the development of cancer by damaging cellular DNA.. The toxicity of plaque, which persists even after airing, only increases with time. The work was published in Mutagenesis.

The main feature of nicotine - the main component of plaque - is its ability to enter into chemical reactions for a long period of time with substances in the room air.. We are talking, in particular, about nitrous acid, which, as a result of combination with nicotine, forms tobacco-specific N-nitrosamines (TSN) - substances with carcinogenic properties.. The interaction of these two components produces 4-methylnitrosamino-4-(3-pyridyl)butanal (TCHA), which is absent in fresh tobacco smoke..

The DNA comet method in combination with quantitative analysis allowed scientists to prove that exposure to TSNA during the day on human cells leads to DNA strand breakage and oxidative stress, as indicated by a high level of genotoxicity of this substance..

It was also found that the effect increases over time due to an increase in the concentration of TSHA. The researchers compared the amount of TSHA in paper strips that were kept for 20 minutes in a closed room in which 5 cigarettes were smoked, as well as in samples that were exposed to cigarette smoke for 196 days.. The room was ventilated at the same time for about 35 hours. The paper strips that had been in the smoky room for the longest time had a much higher concentration of TCHA..

In order to test the effect on cellular DNA of the time difference of being in a smoky room, the authors of the study isolated TSN accumulated in paper samples and exposed it to cells for 24 hours.. The genotoxic effect of TSN, as it turned out, only increases over time..

The effects of smoking cannot be eliminated by conventional cleaning methods.. TSN continue to persist both in dust and on the surface of furniture for more than two months even if smokers do not live in an apartment or house. Researchers advise using radical methods of struggle: make major repairs and buy new furniture.

global science. en.