BACKGROUNDCumulative environmental exposures and social deprivation increase health vulnerability and limit the capacity of populations to adapt to climate change.
OBJECTIVEOur study aimed at providing a fine-scale characterization of exposure to heat, air pollution, and lack of vegetation in continental France between 2000 and 2018, describing spatiotemporal trends and environmental hotspots (i.e., areas that cumulate the highest levels of overexposure), and exploring any associations with social deprivation.
METHODSThe European (EDI) and French (FDep) social deprivation indices, the normalized difference vegetation index, daily ambient temperatures, particulate matter (PM2.5 and PM10), nitrogen dioxide, and ozone (O3) concentrations were estimated for 48,185 French census districts. Reference values were chosen to characterize (over-)exposure. Hotspots were defined as the areas cumulating the highest overexposure to temperature, air pollution, and lack of vegetation. Associations between heat overexposure or hotspots and social deprivation were assessed using logistic regressions.
RESULTSOverexposure to heat was higher in 2015-2018 compared with 2000-2014. Exposure to all air pollutants except for O3 decreased during the study period. In 2018, more than 79% of the urban census districts exceeded the 2021 WHO air quality guidelines. The evolution of vegetation density between 2000 and 2018 was heterogeneous across continental France. In urban areas, the most deprived census districts were at a higher risk of being hotspots (odds ratio (OR): 10.86, 95% CI: 9.87-11.98 using EDI and OR:1.07, 95% CI: 1.04-1.11 using FDep).
SIGNIFICANCEThis nationwide fine-scale study provides a framework to identify environmental hotspots and reveals social inequalities in the cumulative exposure to heat, air pollutants, and lack of vegetation, in France. This approach lends support to the inclusion of environmental and social inequities in adaptation strategies to climate change.