Cigarette Smoking 

The leading cause; contains carcinogens that damage lung cells. 

Exposure to  Radon Gas 

A naturally occurring radioactive gas that can accumulate indoors. 

Passive Smoking (Secondhand Smoke) 

Inhaling smoke from others increases risk significantly. 

Air Pollution 

Long-term exposure to polluted air, especially particulate matter. 

Genetic Factors 

Family history can increase susceptibility. 

Marijuana Smoking  

Contains tar and carcinogens; heavy use can increase risk. 

Age Factor 

Risk increases significantly after age 65. 

Poor Nutrition and Lifestyle Habits 

Low fruit/vegetable intake contributes to lower lung defense mechanisms. 

Metal Fumes From Welding 

Welders are at higher risk due to chromium and nickel particles.