Air pollution-related health vulnerability index assessment: a multidimensional approach highlighting socio-spatial inequalities in urban Dakar

Background Ambient air pollution is an increasingly pressing public health concern in West African cities. In the Dakar metropolitan area (Senegal), socio-spatial inequalities in health vulnerability related to air pollution remain poorly documented, largely due to the lack of comprehensive, disaggregated data, which are often available only at spatial scales too coarse to reflect local disparities. Objective This study aims to assess socio-spatial disparities in health vulnerability to ambient air pollution in two municipalities of Dakar: Hann Bel-Air and HLM. It seeks to identify neighbourhood-level vulnerability patterns to inform place-based public health strategies. Methods A composite health vulnerability index was developed using a multidimensional framework integrating three components: proxy-based residential exposure, derived from traffic-related indicators and population density, health sensitivity, and adaptive capacity. The index was constructed through min–max normalisation and equal aggregation of normalized indicators and was spatialised at the neighbourhood level using household survey data combined with secondary demographic, transport and environmental indicators. Results The results show that high levels of vulnerability are concentrated in densely populated neighbourhoods characterized by high levels of socio-economic insecurity, particularly along major roads and in areas resulting from the fragmentation of traditional village structures in Hann Bel-Air. Conversely, in some residential estates with more affluent populations, vulnerability is lower, even when higher proxy-based exposure scores or health problems are reported, due to a greater adaptive capacity that provides protection against pollution-related effects. Conclusions The spatialised vulnerability index developed in this study demonstrates the value of incorporating exposure, health sensitivity, and adaptive capacity to capture fine-grained socio-spatial disparities. This study’s findings offer an innovative analytical framework to support targeted interventions and context-specific public health planning in urban African settings. It emphasises the importance of addressing both environmental hazards and the social determinants of health, while accounting for locally situated resilience capacities.