Traditional biomass solid fuels are wood, charcoal, agricultural residues and animal dung. In some sub-Saharan African countries (e.g. Chad and Sudan), biomass provides 90 per cent of all energy consumed, and it is estimated to account for most of the household energy needs even in oil-rich sub-Saharan African countries such as Angola (95 per cent), Cameroon (78 per cent), Chad (97 per cent) and Nigeria (65 per cent) (IEA, 2008). The indoor concentration of such pollutants is often several times higher than concentrations recommended by the World Health Organization (WHO), and result in a higher prevalence of respiratory diseases,1 obstetrical problems, eye infections and blindness, among others (IEA, 2002). There is consistent evidence that indoor air pollution increases the risk of chronic obstructive pulmonary disease and of acute respiratory infections in childhood -the leading cause of death among children under five years of age in developing countries.