Asbestos can cause malignant carcinoma of the lung (lung cancer). In a current or past smoker, the chance of developing lung cancer is increased in a multiplicative way. For example a study of insulation workers in the USA demonstrated that the risk of lung cancer was increased 5 times by asbestos exposure, 10 times by smoking but more than 50 times by smoking plus asbestos exposure.

Lung cancer can take 20 — 40 years to develop from first exposure.