Historical statistics support a hypothesis linking tuberculosis and air pollution caused by coal.

Tuberculosis (TB) is generally considered to be linked to industrialisation and urbanisation. Peaking in the 1800s and receding slowly after, the disease declined sharply in the West after World War II. TB has made a comeback in the last 20 years in developing countries such as China and India. Because socio-economic conditions alone cannot explain the connection between industrialisation and TB, factors remain to be determined in the aetiology of the disease. Historical statistics on coal consumption and TB disease in Canada, USA and China are correlated. A hypothesis linking TB and air pollution is developed in the context of industrialisation. A model is proposed whereby triggering of the interleukin-10 (IL-10) cascade by carbon monoxide in lung macrophages promotes the reactivation of Mycobacterium tuberculosis.