Globally, based on data from over 1600 cities, 88% of the urban population are exposed to PM10 or PM2.5 annual mean levels that exceed WHO Air Quality Guideline values. Air quality is poorest in the Eastern-Mediterranean and South-East Asian regions, followed by Latin America and African countries.
Globally, the number of cars and other light duty vehicles is projected to triple between 2000 and 2050; by 2030, the number of vehicles in developing nations is expected to exceed those in developed countries.
Both ‘mobile’ sources (e.g. cars) and ‘stationary’ sources (e.g. smoke stacks) make significant contributions to outdoor air pollution in urban areas. Some major sources include exhaust fumes from vehicles, emissions from manufacturing facilities (e.g. brick kilns), buildings (e.g. for space heating, cooking) and power generation (e.g. coal-fired power plants).
One billion people worldwide with no sanitation facility whatsoever continue to practice open defecation, with no dignity or privacy. Although most of them live in rural areas, the number in urban areas is gradually increasing.
The prevalence of stunting (moderate or severe) among the poorest 20% urban children is four times greater than among the richest 20% urban children in the Americas (including eight countries). In other regions, too, children in the poorest urban households are 2–3 times as likely to be stunted as children in the richest urban households.
Although coverage of sanitation in urban areas has increased in the last decade, the population without sanitation in urban areas actually increased significantly by 215 million to 756 million in 2012, due to population growth outpacing the number of people who gained access to sanitation.