Major sources of population are population growth and urbanization. These can be broken down into: traffic, waste, road dust, industry, and solid fuels. According to the World Bank, more than 80% of the people in Sub-Saharan Africa use solid fuels such as wood and charcoal for cooking. Almost half of the 7 million people who died from air pollution worldwide in 2016 were due to inhaling smoke from biomass-fuelled cookstoves like those used widely in Kenya and many African countries.