How frequently does asbestosis develop into diseases such as lung cancer or mesothelioma?

This would depend on the severity of the asbestosis, i.e. some sufferers can have a mild widespread scarring of the lungs over a life time. However smokers who continue smoking after they have been diagnosed with asbestosis have a fifty five percent higher chance of developing cancer and mesothelioma – particularly if the person smokes more than 20 per day.

Tobacco smoke and asbestos both contribute to each other’s cancer-causing carcinogenic effects, hence, both risk factors combined is more dangerous than the effects of one risk factor alone.