Causes and risks
The commonest cause of lung cancer is smoking. However 10% of people with lung cancer will have never smoked.
Exposure to radon gas, which is naturally occurring in rocks and soils particularly in the South West of the country, can increase the risk of lung cancer. This gas may build up in home and offices, and particularly in people who smoke, can further increase lung cancer risk. If concerned about radon levels in your area, you can contact the Health Protection Agency.
Further risk factors include increasing age, a family history or genetic risks, asbestos exposure and lowered immunity, perhaps due to HIV or immunosuppression following organ transplantation.