Air pollution from biomass fuels in Africa is a significant cause of mortality and morbidity both in adults and children. This paper by D G Fullerton, S Semple, F Kalambo, A Suseno, R Malamba, G Henderson, J G Ayres and S B Gordon describes the nature and quantity of smoke exposure from biomass fuel in Malawian homes.

Summary
Over 2 billion people rely on biomass fuel as their main source of domestic energy. Most of these people live in developing countries such as Malawi, where more than 90% of people cook using biomass fuel (fig 1). Indoor air pollution associated with biomass fuel use is increasingly recognised as a major health concern in the developing world, responsible for an estimated 36% of mortality from respiratory disease as well as contributing to non-respiratory pathology.1 2 3 4 5 Pneumonia is the leading cause of death in children <5 years of age and the risk of pneumonia in young children is increased by exposure to unprocessed solid fuels