The pneumoconioses are by and large industrial diseases, although casual contact may be important on occasion, particularly with asbestos. The effect of dust on the lung ranges from only radiographic changes to severe functional impairment. Destruction and fibrosis of lung parenchyma may be the end result in severe disease. Great improvement has been made in recent years in the control of dust in the numerous situations where it may cause disease. We are still faced with evaluating existing standards of particle concentration in air breathed by workers and establishing safe limits and better control of the particles placed into the general environment. Undoubtedly, there are other particulates which potentially can cause lung disease of which we are not aware. Of even more concern is the realization that a latent period of 20 years or so may be necessary for physicians to become aware of the pathologic process. Every physician who sees patients with pulmonary problems must inquire regarding a history of dust exposure and be prepared to interpret that history.