Source: Department of Science Popularization, Chinese Medical Association
Walking on the street or in a restaurant, it is not difficult to see smokers "swallowing clouds and fog", and tobacco seems to be invading our lives in all directions. At present, the number of smokers in the mainland exceeds 300 million, and the number of people exposed to second-hand smoke has reached 700 million. The enormous health hazards of tobacco cost more than 1 million people a year in China, more than AIDS, tuberculosis, traffic accidents and suicides combined.
We are all familiar with first-hand and second-hand smoke, but is it the first time you have heard of third-hand smoke?
What is thirdhand smoke?
Before we can understand thirdhand smoke, we need to know what firsthand smoke is and what is secondhand smoke.
Firsthand smoke refers to tobacco smoke that smokers inhale into their lungs. Secondhand smoke, on the other hand, is a mixture of smoke and other substances released by the burning end of tobacco and exhaled by smokers, which enters the air and can be inhaled by others.
Sanshou Yan is best at "lurking" and "fighting a protracted war". Third-hand smoke is composed of pollutants deposited indoors when smokers smoke, which can adhere to clothing, furniture, carpets, walls, and even the surface of smokers' hair and skin, and these pollutants can adhere to objects for days or even months, continuing to endanger human health. And third-hand smoke accumulates over time, and also penetrates deep into floors and walls, even if the windows are ventilated and wiped, it is difficult to remove. In addition, third-hand smoke adhering to the surface of the object will also be re-emitted into the air, react with oxidants, and produce secondary pollutants with other compounds. The nicotine adhering to the surface of the object reacts with nitrite acid in the air to form nitrosamines, a carcinogen unique to tobacco.
Is thirdhand smoke harmful to the human body?
The harm of first-hand smoke is clear, and secondhand smoke is equally harmful. Secondhand smoke exposure has been reported to cause asthma, lung cancer, coronary heart disease, and more. Non-smokers exposed to secondhand smoke also increase the risk of smoking-related diseases.
Is that thirdhand smoke harmful to the human body? Although the current exploration of thirdhand smoke is not perfect, research has shown that thirdhand smoke may have a range of health effects, including negative effects on the liver and lungs, as well as slowed wound healing and overactive behavior. Studies have also found that thirdhand smoke increases the risk of lung cancer in mice, and that thirdhand smoke can be absorbed both through inhalation and through the skin compared to inhaled secondhand smoke, with negative health effects.
Children are more likely than adults to be at risk of thirdhand smoke exposure because they stay at home more often and are more likely to come into contact with furniture, carpets, etc. contaminated with thirdhand smoke because they crawl and play. They may also increase their exposure to thirdhand smoke by maintaining close physical contact with the parents who smoke, who often have thirdhand smoke on their clothes, hair, and skin.
How to avoid the effects of thirdhand smoke?
The most effective way to prevent thirdhand smoke exposure is to avoid exposure altogether. If you are a non-smoker, you may need to stay away from smokers' homes and smoking areas. If you smoke, thirdhand smoke is one of the many reasons why you should quit.
As a smoker, the way to prevent the spread of thirdhand smoke pollutants to others is to change your clothes frequently and wash your hands frequently. This is especially important before contact with infants and children.
Author: Chen Meilin Guangxi Academy of Medical Sciences and Guangxi Zhuang Autonomous Region People's Hospital
Reviewed: Jia Yongxing, Executive Editor of Popular Medicine, Shanghai Science and Technology Press