title: Debate on the paper by Diez Roux.
authors.affiliation: Laboratorie Dynamiques Sociales et Recomposition des Espaces, Université Paris Ouest, Nanterre, France, salem.gerard@gmail.com.
authors.forename: Gérard
authors.initials: G
authors.lastname: Salem
mesh_terms: D002947:Cities; D006801:Humans; D014504:Urban Health