The relationship between air pollution exposure and income: empirical findings from France at the municipality level from 2009 to 2019

Abstract Do poorer people face lower environmental quality? To explore this question, which is at the heart of environmental justice issues, we study the relationship between air pollution exposure and income at the municipality level using French data between 2009 and 2019. We study four different pollutants: fine particulates (PM2.5), suspended particulates (PM10), nitrogen dioxide (NO2) and ozone (O3). We compute the average pollution levels in municipality ventiles based on their median standard of living and study the shape of the relationship between these two variables as well as its evolution over time. We refine the analysis by taking the degree of urbanization and World Health Organization (WHO) thresholds into account, as well as creating multi-exposure indicators. We find that exposure levels decreased between 2009 and 2019 for all pollutants except O3. The shapes of relationships are generally stable over time, but differ significantly from those observed in other countries, especially the US. We identify PM10 and NO2 in urban areas, as well as O3 in rural areas, as cases of particular concern where levels exceed WHO thresholds and disproportionately impact low-income municipalities. These results are important for identifying and protecting the most vulnerable populations.