How harmful is asbestos?

Depends on the type.: The are various types of asbestos, depending on the chemical makeup and fiber size/shape. Some types seem to be more harmful than others, but all types should be considered harmful and carcinogenic. Asbestos can cause serious lung disease (asbestosis) or deadly cancer of the lung or abdomen (mesothelioma). Smoking combined with asbestos exposure greatly raises the lung cancer risk.