Air pollution is the cause of 7 million premature deaths worldwide. Out of this 7 million, 2.6 million premature deaths are caused by indoor air pollution (IAP).
In a developing world, IAP  is caused primarily by the inefficient burning of solid fuels (such as firewood, dung cakes, agricultural residues and coal) in the households for cooking or heating. Thus, IAP is more prominent in rural areas of the developing world and mostly affects the cooks, who in general are women and accompanying children. Impact of IAP is more in case of poorly ventilated kitchens and houses. As per the energy ladder theory, the poor households tend to depend on solid fuels much more than the affluent households. The International Energy Agency (IEA) in its Energy and Air Pollution report (2017) suggests providing clean cooking facilities to an additional 1.8 billion people by 2040 to reduce household emissions in developing countries.