Advance Access publication February 28, 2005 EDITORIALS AND COMMENTARIES The Urban Health “Advantage”

Cities represent the dominant mode of living in the developed world and the pace of urbanization worldwide will continue to accelerate over the coming decades, partic-ularly in the developing world.1 According to United Nations 2000 forecasts, about half of the world’s population is urban and by the year 2030 nearly two thirds of the world’s population will live in urban areas.2 About 75 % of the US population lives in urban areas; according to the Office of Management and Budget, 90 % live in more broadly defined metropolitan statistical areas (MSA). The National Center for Health Statistics, using a newer measure of urbanization, based on proximity to urban centers, finds that the proportion of persons living in MSA central city, MSA noncentral city, non-MSA adjacent, and non-MSA nonadjacent are approximately 29.5%, 48.3%, 12.1%, and 10.1 % of the US population, respectively.3 Health and disease in urban populations have been the subject of much popular and scientific literature. The historical perspective of cities is that their size and den-sity, coupled with a pace of growth through immigration and commerce that out-strips resources, all result in exposures that produce excess morbidity an