Environmental justice and health: the implications of the socio-spatial distribution of multiple environmental deprivation for health inequalities in the United Kingdom

Understanding persistent and increasing spatial inequalities in health is an important field of academic enquiry for geographers, epidemiologists and public health researchers. Delivering robust explanations for the growing spatial divide in health offers potential for improving health outcomes across the social spectrum, but particularly among disadvantaged groups. One potential driver for the increasing geographical differences in health is the disparity in exposure to key characteristics of the physical environment that are either health promoting or health damaging. While the framework of 'environmental justice' has long been used to consider whether disadvantaged groups bear a disproportionate burden of environmental disamenities, perhaps surprisingly, the research fields of environmental justice and health inequalities have remained largely separate realms. In this paper we examine the confluence of environmental characteristics that potentially function as key mechanisms to account for the socio-economic gradient in health outcomes in the UK. We developed the Multiple Environmental Deprivation Index (MEDIx), an area-based measure that represented the multiple dimensions of health-related environmental disamenities for census wards across the UK. By comparing the index to an area measure of income deprivation, we found that, at the national level, multiple environmental deprivation increased as the degree of income deprivation rose. Using mortality records we also found that MEDIx had an effect on health that remained after taking into account the age, sex and socio-economic profile of each area. Area-level health progressively worsened as the multiple environmental deprivation increased. However, this effect was most pronounced in least income-deprived areas. Our findings emphasise the importance of the physical environment in shaping health, and the need to consider the social and political processes that lead to income-deprived populations bearing a disproportionate burden of multiple environmental deprivation. Future research should simultaneously consider the 'triple jeopardy' of social, health and environmental inequalities.