What causes lung cancer?

Mainly smoking: But a lot of other factors (most of which can nit be altered) may play a role. Over 85% of lung cancers are seen in smokers, so if you would like to decrease your chances of getting lung cancer (and also cardiovascular disease!) quit smoking now!

Several causes...: But the most common correlation with lung cancer is smoking. Smoking alone will increase your risk of lung cancer by about 20 times by smoking one pack per day for twenty years. Other sources can be genetic (alpha-1 antitrypsin disorder), related to environmental exposures that are inhaled, or other less common reasons.

80% by smoking: Second common cause is radon. Second hand smoke is also common cause of lung cancer.

Many things: >80% of lung cancer is caused by smoking. However never smokers (defined as <100 cigarettes in lifetime) can get smoking. Risk factors include radon exposure, second hand smoke, and genetic mutations such as egfr activating mutations. For more info: http://bit.Ly/ygfoko.

Exposure: Risks of lung cancer: http://goo.Gl/gu9ms as noted by others, number one/major cause is exposure to inhaled carcinogens, particularly combustion/burning products (i.e. Tobacco, marijuana, etc...). Other inhalants are also noted risk factors. Be well and respect yourself.

Smoking!: Smoke from cigarettes contains approximately 35 known chemicals to cause tumors in lab rats. Smokers have a much higher incidence of lung cancer over the non-smoking population. Asbestos inhalation increases risk for mesothelioma, a very aggressive form of lung cancer. Radon, a radioactive decay product from soil uranium, is thought to be the second leading cause of lung cancer in the usa.

SMOKING SMOKING : And smoking the biggest and most significant risk factor. 90% of lung cancers develop in people who have smoked. Other causes: asbestos exposure, radon.

Risk factors: Lung cancer is most commonly a long process of years in which the lungs are exposed to damaging substances/"carcinogens". The biggest/best known is smoking. This link may help: http://www.Cancer.Net/cancer-types/lung-cancer/risk-factors-and-prevention.