Every breath connects our lungs to the world around us. With each inhale, we take in not only oxygen, but also particles, pollutants and chemicals present in the air.
That makes what we breathe an important part of lung health.
Exposure can come from many sources, including outdoor air pollution, vehicle exhaust, industrial emissions, household air pollution, dust and smoke. Long-term exposure to some of these pollutants can contribute to respiratory disease and increase the risk of lung cancer.
On World Lung Day, lung cancer deserves particular attention. It remains the world’s most commonly diagnosed cancer and the leading cause of cancer death. In 2024, almost 2.65 million people were diagnosed with the disease and more than 1.8 million died from it.
According to World Health Organization, among the different risks, cigarette smoking remains the most significant, accounting for approximately 85 per cent of lung cancer cases.
A pulmonologist, Prof. Dr. Syed Arshad Husain, believe that four of the most serious lung and heart conditions trace back to one habit: smoking. “It’s linked to lung cancer, COPD, heart disease, and stroke, and it raises your risk of pneumonia while making asthma worse. Different diseases, same root cause: cigarette smoke,” he said.
The question, then, is what makes cigarette smoke so harmful.
When tobacco burns, or combusts, it produces smoke containing more than 6,000 chemicals. These substances are inhaled directly into the lungs, where repeated exposure can damage tissue, trigger inflammation and impair normal lung function.
Nicotine plays a different role. It is addictive and is one of the main reasons people find it difficult to stop smoking. However, much of the serious disease associated with cigarettes is linked to the toxic chemicals produced and inhaled when tobacco burns.
The impact also extends beyond the smoker.
A burning cigarette releases smoke into the surrounding air, exposing other people to many of the same harmful substances. Second-hand smoke is associated with serious cardiovascular and respiratory diseases, including lung cancer.
This is why combustion has become an important part of the discussion around reducing smoking-related harm. If tobacco is not burned, conventional cigarette smoke is not produced.
Different approaches are therefore being used to help smokers move away from combustible cigarettes. These include established smoking-cessation options such as nicotine gums and patches, as well as other smoke-free products that deliver nicotine without burning tobacco.
These alternatives are not risk-free, and nicotine remains addictive. They should also not be used by people who do not already smoke or use nicotine.
For smokers, quitting cigarettes, and ultimately tobacco and nicotine altogether, remains the best option for health.
But for adults who would otherwise continue smoking, eliminating combustion can reduce exposure to many of the harmful chemicals produced in cigarette smoke.
On World Lung Day, the message remains simple: protect the lungs from harmful exposure wherever possible, prevent people from starting smoking and support smokers who want to quit.
Because when it comes to lung health, what we breathe matters.
