**2.7 Air pollution**

Air pollution is also an important risk factor for lung cancer. Around 5% of all deaths from lung cancer may occur due to outdoor air pollution worldwide.

## **2.8 Personal or family history of lung cancer**

First-degree relatives of lung cancer patients have an increased risk to develop cancer.

## **2.9 Other lung diseases and airways obstruction**

Some non-malignant diseases like COPD are associated with an increased risk for lung cancer. Tobacco smoking is the primary risk factor causing both lung cancer and COPD. Patients with interstitial fibrosis are at an increased risk of lung cancer.

#### **2.10 Genetic factors**

Susceptibility to lung cancer is determined by host genetic factors. Tobacco smokers with genetic susceptibility are at a higher risk.
