WHO – Megacities and urban health

WHO – Megacities and urban health. December 2009.

Full-text: http://www.who.or.jp/2009/reports/Megacities_Report_DEC09.pdf (pdf, 275KB)

Megacities are cities of 10 million or more inhabitants. There are more than 20 megacities in the world and they are highly diverse. They concentrate national and global economic and political power as well as scientific, political and media attention. When analysing health in megacities, it is difficult to separate the effect of size from other variables. However, cities of similar size do not necessarily suffer from the same problems, and at the same time common issues can be found among cities of very different dimensions. Nevertheless, starting with an analysis of their common characteristics, we identify nine challenges that megacities face which have particular health impact: transportation, governance, water and sanitation, safety, food security, water and sanitation, health care, emergency preparedness, and environmental issues. Each challenge is analysed in terms of its relationship with urban health. They are highly influenced by the complexity of megacities in terms of population size, geographical extension, social inequalities, and usually multiple and fragmented metropolitan governments. We conclude that given the variation among megacities and the extent of commonalities between megacities and other lower population settings, the relevance of the megacity as a category in urban health is limited. Yet the identification of these challenges, and the different ways in which they are being handled, is useful for shedding light on determinants of health and potential intersectoral interventions in a range of urban settings well beyond this group of cities.