Ezzati and Kammen (2001, 2002) present indoor PM concentration measurements also for several types of charcoal stoves. PM concentrations are found to be substantially lower than concentrations from fuel wood stoves. Charcoal is often considered by households as an intermediate fuel on the energy ladder. While it certainly is not considered a clean fuel, it is often a preferred choice in many urban areas whenever available instead of fuel wood, before households can afford LPG or other clean alternatives. In some Sub-Saharan countries the use of charcoal is relatively widespread especially.
