Exposure to dust in the workplace is associated with a variety of pulmonary and systemic illnesses. Occupational diseases are often thought to be uniquely and specifically related to factors in the work environment. These are group of diagnoses caused by the inhalation of dusts, chemicals, or proteins. “Pneumoconiosis” is the term used for the diseases associated with inhaling mineral dusts. Pneumoconiosis means “dusty lungs.” The reactions that occur within the lungs vary with the size of the dust particle and its biologic activity. Some dusts like barium, tin, iron do not result in a fibrogenic reaction in the lungs, but others can evoke a variety of tissue responses. Such responses include silicosis, asbestosis and coal worker’s disease. These also include chronic obstructive pulmonary disease and mesothelioma.