Final answer:
Smoking is the most prevalent risk factor for lung cancer, responsible for approximately 85 percent of cases, while other factors such as radon exposure and air pollution also contribute to the risk.
Step-by-step explanation:
The most prevalent risk factor for lung cancer is smoking. Cigarette smoke contains numerous cancer-causing chemicals, making tobacco smoking responsible for about 85 percent of lung cancer cases. While there are other potential causes such as exposure to radon gas, asbestos, secondhand smoke, poor diet, physical inactivity, and air pollution, none rival the impact of smoking. The combined effects of smoking with other risk factors, like radon exposure, significantly heighten the risk of developing lung cancer. It is also important to note that tobacco use is linked to various other types of cancers, increasing the need for prevention and cessation efforts.
The U.S. Environmental Protection Agency (EPA) also highlights radon as a notable environmental risk of lung cancer, especially when combined with the risks from smoking. However, the highest priority in prevention is the avoidance of tobacco smoke, given the high proportion of lung cancers linked to this behavior.