The main symptoms are a cough and breathing difficulty. It may take at least ten years of exposure to dusts containing coal, silica, talc, or asbestos before serious lung damage develops (see pneumoconiosis). Hypersensitivity to moulds on hay or grain may lead to allergic alveolitis.
Preventive measures, such as the installation of dust extraction machinery, have reduced the incidence of dust diseases, and replacements have been found for especially hazardous substances such as asbestos.