Editorial

Looking upstream for influences on socio-economic inequalities in health The authors of a recent article on health and urban planning1 observed that ‘[r]ich and poor people live in very different epi-demiological worlds, even within the same city’. The authors did not elaborate upon or theorize this point, but it is more than a statement of the obvious and underscores the import-ance of explaining health inequalities with reference to complex sets of exposures and vulnerabilities2 that occur sim-ultaneously or sequentially, vary across socioeconomic gradi-ents, and have effects that often accumulate over the life course. In this issue, the study of Detroit by Kwarteng et al.3 adds an important contribution to the literature on how the physic-al condition of neighbourhoods influences residents ’ physica