If you smoke 1-4 cigarettes a day, you are 5 times more likely to die from lung cancer than a non-smoker.
Source: Lung cancer risk factors @ Cancer Research UK
Image by Challiyil Eswaramangalath Vipin from Chalakudy, India (cigarette.. like a cigarette in the rain) [CC-BY-SA-2.0], via Wikimedia Commons
