Smoking is identified as one of the most important causes of lung cancer due to the numerous harmful substances present in tobacco smoke. When individuals smoke, they inhale a mixture of over 7,000 chemicals, many of which are known carcinogens (cancer-causing agents). The most critical ones, such as tar and various tobacco-specific nitrosamines, damage the DNA in lung cells and promote the development of cancerous tumors. The correlation between smoking and lung cancer is well-documented through extensive research, which has shown that smokers are significantly more likely to develop lung cancer compared to non-smokers.
While secondhand smoke, air pollution, and genetic predisposition can also contribute to the risk of developing lung cancer, their effects are often considered secondary in comparison to the direct impact of smoking. Smokers, particularly heavy smokers, have an exceedingly higher rate of lung cancer, which reinforces the classification of smoking as the most significant risk factor. This link emphasizes the importance of smoking cessation programs and public health initiatives aimed at reducing tobacco use to combat lung cancer effectively.