World No Tobacco Day | Do you know how closely smoking is related to lung cancer?

May 31, 2022 is the 35th "World No Tobacco Day". We know that tobacco pollutes the earth and harms the health of everyone throughout its life cycle. So, how much is the relationship between smoking and lung cancer? How toxic are secondhand smoke and thirdhand smoke? Why is it so difficult to quit smoking? Are e-cigarettes really "low-harm"? Professor Zhi Xiuyi, director of the Lung Cancer Diagnosis and Treatment Center of Capital Medical University, once gave a popular science lecture in the Capital Science Lecture Hall titled "How to Care for Our Lungs During the Epidemic?", teaching you to stay away from tobacco and care for your lungs. Let's quickly get the knowledge points together!

How closely is smoking related to lung cancer?

When talking about the harmfulness of smoking, we cannot avoid mentioning nicotine. Because nicotine in tobacco is addictive, after long-term smoking, the human body will have a strong need to maintain nicotine levels, which is the addiction stage. When you are entangled with nicotine in tobacco, you have to accept the damage of harmful substances in tobacco. Over time, you will get smoking-related diseases.

A large number of epidemiological studies have confirmed that smoking is the primary risk factor for lung cancer. Among patients who die from lung cancer, 87% are caused by smoking (including passive smoking).

How toxic are secondhand smoke and thirdhand smoke?

Smoking is not only harmful to the health of smokers themselves, but also exposes others to second-hand and third-hand smoke.

The so-called second-hand smoke is formed by the mainstream smoke and sidestream smoke exhaled by smokers mixing with the surrounding air; third-hand smoke is the residue of tobacco smoke and its chemical components that remain on the surface of objects and in the dust after smoking.

Compared to mainstream smoke, sidestream smoke contains more toxic chemicals, such as 15 times more formaldehyde and 3 times more styrene. Newly emitted sidestream smoke particles are smaller than mainstream smoke particles, so they can penetrate deeper into the lungs and enter the bloodstream more easily. The same unit volume of sidestream smoke is 4 times more toxic than mainstream smoke and 2-6 times more carcinogenic than mainstream smoke.

Thirdhand smoke will undergo chemical changes over time, so the toxicity of some of its compounds will increase. Indoor environments polluted by thirdhand smoke will expose people to tobacco smoke pollutants for a long time without them noticing.

Therefore, even if you do not smoke, you should still be wary of secondhand smoke and thirdhand smoke.

Why is it so difficult to quit smoking?

Old smokers actually know that there are many benefits to quitting smoking, but they still fail to quit smoking again and again, and often relapse after being persuaded by their fellow smokers. Why is it so difficult to quit smoking? How can you quit smoking successfully?

Health Benefits of Quitting Smoking

We must realize that tobacco dependence is a chronic nicotine addiction disease. To treat tobacco dependence, you must quit smoking correctly and scientifically. If you have a smoking-related disease and have entered a sub-healthy state, it is best to seek help from the hospital's smoking cessation clinic, develop an individualized smoking cessation plan under the guidance of a doctor, and then proceed with the subsequent smoking cessation process.

The results of two large-sample case-control studies in the UK in 1950 and 1990 showed that quitting smoking before middle age can reduce more than 90% of the risk attributable to tobacco. For smokers, it is never too late to quit smoking, and of course the sooner the better.

Are e-cigarettes really “low-risk”?

In the past five years, many e-cigarettes have flooded the market. They are affecting our lives and endangering our health.

Electronic cigarettes are a system that produces inhalable aerosols, which are composed of electronic cigarette devices and electronic cigarette liquid. It is mainly composed of a battery pack, an atomizer, and a cigarette cartridge/liquid. The tobacco leaves and battery pack are powered and heated, and the oil in the cigarette cartridge is heated to be atomized for users to inhale. This is actually a disguised form of tobacco, and it is still a tobacco product. At the same time, the secondhand aerosol produced by the electronic cigarette heating solution is a new source of air pollution.

The original intention of developing e-cigarettes was to eliminate harmful substances other than nicotine in tobacco and only provide nicotine to smokers, but many chaos have occurred in the industry during actual application.

First, as a smoking cessation drug, e-cigarettes have measurement requirements when providing nicotine to old smokers. However, the nicotine concentration values ​​in many e-cigarettes are not standardized at all, and excessive nicotine addition can be life-threatening. Secondly, e-cigarettes no longer only provide nicotine, but also add many additives, such as synthetic mint flavors and chocolate flavors. It is currently known that more than 8,000 flavorings are added to e-cigarettes, and their impact on health remains to be evaluated. Finally, e-cigarettes are no longer satisfied with providing smoking cessation services for old smokers, but are sold to non-smokers, teenagers, fashionable women, etc., which runs counter to the concept of helping to quit smoking that they promote.

Electronic cigarettes with various additives

Compared with other groups, e-cigarettes are particularly harmful to teenagers. Among teenagers who have never smoked, many teenagers will take the initiative to try e-cigarettes because of the "low harm" advertised in e-cigarette advertisements, as well as the simple and fashionable design and cool and diverse flavors. However, any tobacco product is harmful, including e-cigarettes. For minors, nicotine will affect the still developing brain and impair learning and memory abilities.

This brings up an astonishing fact: e-cigarettes, which were originally invented for adults to quit smoking, have become a new addiction tool for teenagers!

In order to deal with this situation, it is necessary to further improve and promote tobacco control legislation and strengthen supervision of the market that illegally sells to minors. It is hoped that through relevant policies and regulations, popular science publicity and education for young people, strict control of e-cigarettes can be achieved to reduce their harm to young people.

Source: Capital Science Lecture Hall