Smoky dust

In 2017, a group of researchers from the Lawrence Berkeley National Laboratory (USA) proved that inhaling toxic substances of tobacco smoke lingering in dust leads to a decrease in body weight and a weakening of immunity in young mice. In a new study, they show that the harm from passive smoking, even when the cigarette has been extinguished for a long time, is much more serious. In an experiment on young mice, it increased the risk and aggravated the course of lung cancer.

It has been proven previously that toxic substances that settle on the surface after smoking indoors are not removed by traditional cleaning methods and remain for a long time. They can enter the body by breathing, as well as by ingestion and direct contact with the skin. That is why young children crawling on the floor and putting toys in their mouths are most susceptible to the harmful effects of smoking through third hands.

In the new study, experiments were conducted with 24 mice of a line prone to spontaneous development of lung cancer, aged from four to seven weeks. A piece of cloth soaked in tobacco smoke was placed in the cage with the animals. The researchers estimated the daily dose of dozens of toxins and carcinogens by the concentration of nicotine, which was 77 micrograms/kg – a similar amount is inhaled on average by a child living next to a smoker. 

After 40 weeks, these mice developed lung cancer (adenocarcinoma) more often than in the control group, and the disease proceeded more aggressively.

After smoking indoors, substances are deposited on all surfaces that, when interacting with air, form extremely toxic compounds that contribute, among other things, to the development of lung cancer. In an in vitro study, this process was studied in more detail.

Toxic compounds formed after the interaction of resins with air cause double-stranded DNA breaks. If the repair process does not occur in time, protein synthesis is disrupted, and the cell turns into a cancerous one. Its uncontrolled proliferation begins, leading to rapid tumor growth.

Smoking through third hands also leads to stress in the endoplasmic reticulum of cells and a response in the form of increased production of the protein p53, which is a suppressor of oncogenesis.

Further research is needed, but now we can safely conclude that smoking in a family with young children is dangerous for the health of not only the smoker, but also children, even if the child does not inhale smoke directly at the time of smoking.

Article by B. Hang et al. Short-term early exposure to thirdhand cigarette smoke increases lung cancer incidence in mice published in the journal Clinical Science.

Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru Based on Lawrence Berkeley National Laboratory: Third Hand Smoke Found to Increase Lung Cancer Risk in Mice.