Patients are said to have chronic bronchitis when they produce sputum on most days for at least three months in the year over a period of at least two years. A person who develops chronic bronchitis can experience respiratory infections and shortness of breath. Because air exchange is impaired, a person who develops emphysema experiences shortness of breath that occurs during strenuous exertion in the early stages of the disease and even at rest in later stages. Asthma Asthma is characterized by the reversible narrowing of air passages, that may lead to permanent damage. A person who develops asthma experiences chest tightness, shortness of breath and often wheezing and coughing.
Many factors contribute to the development of chronic obstructive lung diseases.
These factors may relate to personal conditions or activities as well as working conditions. Cigarette smoke, air pollution, and various workplace dusts, fumes, vapours, and gases have all been associated with obstructive lung diseases. Many epidemiological studies consistently show relationships between occupational exposure to airborne contaminants and the incidence of chronic airway diseases. Because many factors contribute to chronic obstructive lung diseases, they cannot be classified as occupational disorders. OSH Answers Search Help OSH Answers Search is designed to help you specifically target items about Occupational Health and Safety that are explained in the OSH Answers portion of our site.