Investigating inequalities in NO₂ air pollution concentrations on novel indicators relating to small spatial areas

Nitrogen dioxide (NO₂), a significant air pollutant from transport-related fossil fuel combustion, presents a critical environmental health challenge. This study analyses NO₂ trends in Ireland from 2010 to 2020, leveraging the country's low-pollution baseline as a unique case study to analyse inequalities in NO₂ concentrations across the country. Data at a small area level from Census 2022 were integrated with measurements of NO₂ concentrations to assess environmental inequalities across novel indicators such as housing tenancy and self-rated health alongside conventional socioeconomic measures. The research uncovers clear evidence of environmental inequalities in NO₂ concentrations, with higher levels found in neighbourhoods with larger proportions of non-white populations and non-owner-occupied housing. A stratified urban-rural analysis shows these disparities were most pronounced in urban areas. A U-shaped relationship between NO₂ levels and deprivation, educational attainment, and skills, suggests that while the most and least deprived may experience similar NO₂ concentrations, the health burden on disadvantaged groups may be amplified by co-occurring vulnerabilities. These findings underscore an urgent need for targeted interventions to mitigate the disproportionate burden of NO₂ air pollution on vulnerable communities in Ireland.