According to clinical oncologists, both first-hand and second-hand smoke can be equally harmful to the lungs, and the recurrence and mortality rates are quite high once lung cancer develops. Statistics found that one quarter of lung cancer cases are caused by long-term secondhand smoke or other causes. According to foreign studies, a non-smoker married to a smoker has a 30% higher risk of developing lung cancer than a non-smoker. So it’s the same old story: for your own sake and for the sake of others, please quit smoking early. The risk of smoking a pack of cigarettes a day for 20 years is 20 times higher According to the World Cancer Research Fund, lung cancer is a global health threat. And smoking is the biggest cause of lung cancer, followed by severe air pollution. One of the reasons for the high lung cancer mortality rate is that most early stage lung cancers have no obvious symptoms, so many patients have already progressed to stage IV lung cancer by the time they first seek treatment. Individuals who smoke one pack (20 cigarettes) a day for 20 years have a 20 times higher risk of lung cancer than non-smokers. However, those who have quit smoking for more than 10 years will have a similar chance of developing lung cancer as non-smokers. The risk of cancer from secondhand smoke is three times higher. Is firsthand smoke or secondhand smoke more influential? In fact, both have the same risk of causing lung cancer. The tar in cigarettes is an important carcinogen, and both smokers and secondhand smokers will inhale tar-laden smoke at the same time. Even the low amount of secondhand smoke is very toxic, because smoking firsthand, the filter on the cigarette blocks some of the tar; but on the contrary, secondhand smoke is inhaling the exhaust from the smoker plus the smoke released when the cigarette burns, in which the tar content of each unit of smoke is actually higher. Tar will not only block and stimulate the airways and lungs, causing coughing, but will also stain the lung tissue, directly affecting lung function, the longer the smoking age, the more likely to become lung cancer. Three quarters of lung cancers are related to direct smoking, and one quarter belong to non-smokers who inhaled secondhand smoke for a long time or caused by other reasons, which shows that the proportion of secondhand smoke causing the disease is quite high. It should not be overlooked that smokers who smoke in a closed indoor environment, burning cigarettes or unused cigarette ashes will continue to release cancer-causing gases, and smokers’ lungs will be doubly damaged. In addition, the increasingly serious air pollution is also one of the causes of the disease, the most common are car exhaust, factories, restaurants, etc., all have a certain impact on our lungs. In addition, people who work in places where the air is cloudy for a long time, such as garages, renovation or painting workers, are also at high risk because they have the opportunity to be exposed to or inhale harmful substances, such as asbestos, silicon and zinc, which are harmful to lung health. By recognizing these susceptibility factors of lung cancer, we can prevent, detect and treat it early, and make concerted efforts to reduce its harmful effects. Patients should quit smoking immediately after surgery, because whether they have undergone surgery, chemotherapy or electrotherapy, their lungs have been damaged, so if they continue to smoke, it will only stimulate their lungs and cause coughing and sputum, which will increase the chance of recurrence or spread. Regardless of whether you are a lung cancer patient or not, it is most important to quit smoking and avoid second-hand smoke as much as possible, wear a mask when you frequent places where the air is turbid, pay attention to a balanced diet and exercise more often to keep your body healthy and prevent the disease before it happens.