4. Lung Cancer

Thesis: Risk factors for lung cancer include, cancer (family history), smoking, exposure to secondhand smoke, radon gas, asbestos and other carcinogens. All increase the risk of lung cancer especially with repeated exposure damaging and changing the lung tissue right away.
Evidence: Risk of lung cancer increases with each cigarette smoked each day every year, quitting early decreases chances developing lung cancer. Even not smoking but inhaling it is a risk and increases the risk. Radon is produced from the uranium in soil, rock, and water that becomes apart of the air we breath, but unsafe levels of radon can build up in buildings and homes. Buildings and homes can contain asbestos and other carcinogens which is known for the causes of cancer. Cancer that runs in the family increases the risk of lung cancer. 
So-What: Ways to prevent and decrease the risks can be to quit smoking at a young age which can significantly lower chances of development. Radon testing kits are available for purchase at home improvement stores to test whether your environment is safe. If it happens to be unsafe, treatment is also available. Improving your lifestyle to increase your lung health is to relax and do breathing exercises (deep breaths), laugh, exercise regularly, healthier diet, hydrate, keeping your airways clear and breath through your nose.