When it comes to lung cancer, many people's first reaction is "caused by smoking", thinking that as long as they avoid cigarettes, they can rest assured.
In fact, the occurrence of lung cancer is a result of the combined effects of various factors such as genetics, environment, and lifestyle habits. Smoking is merely the most significant risk factor among them, rather than the sole one.
Why can one get lung cancer if they don't smoke?
▌ Most common cause: passive smoking (second-hand smoke + third-hand smoke)
For many non-smokers, the risk of lung cancer actually comes from the smokers around them - the hazards of second-hand smoke and third-hand smoke are far greater than we imagine.
Second-hand smoke contains over 70 carcinogens, including nicotine, tar, and benzopyrene. Prolonged exposure to second-hand smoke directly increases the risk of lung cancer among non-smokers by 20%-30%.
Third-hand smoke is even more insidious: it is the harmful substances that remain on clothing, furniture, walls, and carpets after a cigarette has been extinguished. These substances can persist for weeks or even months, and even after the smoker has left, they continue to evaporate, posing a threat to human health, especially affecting the elderly, children, and pregnant women more significantly.
▌Invisible killer: Indoor and outdoor air pollution
The air we breathe every day may be silently damaging our lungs, becoming an "invisible trigger" for lung cancer.
Outdoor level: Fine particulate matter such as PM2.5 from haze, industrial waste gas, and vehicle exhaust can directly damage lung cells when inhaled over a long period, gradually increasing the risk of cancerization;
Indoor level: The hazards of kitchen fumes are often overlooked. Fumes generated from long-term high-temperature frying contain carcinogens such as polycyclic aromatic hydrocarbons. Especially for those who do not pay attention to ventilation or use range hoods, the risk increases significantly. In addition, harmful substances such as formaldehyde and radon gas (mainly from soil and building materials) in newly renovated houses can also cause serious lung damage due to long-term accumulation.
▌Other key factors: genetics + past medical history + occupational exposure
① Genetic factors: If a first-degree relative (parents, children, siblings) has lung cancer, the individual's risk of developing lung cancer is significantly higher than that of the general population, which may be related to genetic susceptibility genes or similar living environments;
② Previous lung diseases: People with chronic obstructive pulmonary disease, tuberculosis, pulmonary fibrosis, and other lung diseases have lungs that are in a state of inflammation for a long time, with cells repeatedly damaged and repaired. The probability of canceration increases significantly;
③ Occupational exposure: Certain occupational groups, such as miners, welders, and painters, who are exposed to carcinogens like asbestos, arsenic, chromium, and nickel for extended periods, face a significantly elevated risk of lung cancer, even if they do not smoke.
These people are at high risk of lung cancer
According to relevant guidelines, the following groups of people are considered high-risk for lung cancer. It is recommended to prioritize screening and prevention for them. Don't ignore them!
① Smokers and passive smokers
Including: current smokers who smoke 1 pack of cigarettes (20 cigarettes per pack) per day for over 20 years, or smoke 2 packs of cigarettes per day for over 10 years; former smokers who have quit smoking for less than 15 years; and passive smokers who have lived or worked with smokers for over 20 years.
② Age- and genetic-related populations
Individuals aged between 50 and 74 who have a first-degree relative diagnosed with lung cancer belong to a high-risk group and require special attention to their lung health.
③ Occupational exposure population
Individuals who have been exposed to carcinogens such as asbestos, radon, coal smoke, and heavy metals for a long time, with at least one year of occupational exposure history (such as miners, construction workers, chemical workers, etc.), need to take occupational protective measures and undergo regular screenings.
④ People with a history of previous lung diseases
Individuals with chronic obstructive pulmonary disease, tuberculosis, pulmonary fibrosis, or other lung diseases, or those who exhibit abnormalities such as ground-glass nodules on lung CT scans, face a significantly elevated risk of lung cancer.
Important reminder: Don't ignore early screening for lung cancer!
The vast majority of early-stage lung cancers are asymptomatic, occasionally accompanied by symptoms such as expectoration with blood streaks or unexplained chest pain, which can easily be overlooked as a common cold.
For the aforementioned high-risk groups, it is recommended to undergo low-dose spiral CT screening once a year - this is currently internationally recognized as the most effective means of early detection of lung cancer.
Not smoking does not mean you won't get lung cancer. We should completely abandon the misconception that "only smoking can cause lung cancer" and pay attention to the invisible risks around us: ensure good indoor ventilation, stay away from second-hand smoke, and take occupational protective measures.
Meanwhile, high-risk groups should proactively undergo regular screenings to facilitate early detection, diagnosis, and treatment, thereby minimizing the harm caused by lung cancer. Protecting lung health begins with scientific understanding and proactive prevention
Expert Introduction
Wu Jun, Chief Physician
Thoracic surgery specialist
Associate Professor, Master's Supervisor
Hainan Free Trade Port Category D Talent
Medical expertise
He is skilled in personalized treatment for thoracic tumors such as lung cancer and esophageal cancer. He has accumulated considerable experience in minimally invasive surgery for thoracic tumors, particularly in the prevention and treatment of thoracic surgical complications, and has conducted in-depth research in diagnosis and treatment.