Spatial scale and spatial effects: Shedding light on how a change of scale can affect the characterization of environmental health inequalities

Abstract

Resolving health inequalities continues to be a priority in improving quality of life around the world. Their impact is of increasing concern to public health governance, which considers the issue of environmental health inequalities to be paramount. To meet this challenge, we have developed a methodology based on the development of spatial composite index in order to assess these inequalities while also providing an alternative to classic approaches that are solely based on territory weaknesses. The aggregation of the widest possible range of factors involved in environmental health provide a clear picture of a territory. This study uses different cases to understand how the change of scale influences the analysis of environmental health inequalities. Our analysis is based on a densely populated area located in a region in the north of France where the standardized mortality ratio is higher than the national average. Multidimensional composite indices were developed simultaneously from datasets collected for different administrative units, and were used to compare levels of resilience and vulnerability within the geographical area. Joint analysis of composite indices led to the identification of territorial blackspots. Indices could therefore enable stakeholders to prioritize certain administrative units, implementing specific measures according to the specificities of each administrative unit. The study discusses the consequences of the choice of a spatial unit and a geographical area in the assessment of territorial inequalities in health, particularly in terms of accessibility, availability and exhaustivity of data. The selection criteria also depend on the jurisdictional fields of action stakeholders.