Chronic bronchitis and emphysema are common ailments in the United Kingdom. Death from these diseases is often preceded by years of progressive disability. The earlier stages of bronchitis are characterised by recurring attacks of coughing and phlegm due to damage to the cilia which normally sweep the mucous out of the lungs. In the later years there is a narrowing of the air passages.

Emphysema describes the condition where the walls of the alveoli are broken down to produce larger air spaces, resulting in a smaller surface area for gaseous exchange. The incidence of both bronchitis and emphysema is increased by air pollution, including tobacco smoking. The presence of sulphur dioxide in the air is a common cause of bronchitis and the inhalation of large quantities of fine dust is related to the development of emphysema. Coal mining is an occupation in which these respiratory diseases become more frequent.