Environment/Climate Change
Interaction between social deprivation and air pollution on mortality in hexagonal France: A nationwide analysis, 2018-19. Tom Fischer* Tom Fischer Stéphanie Vandentorren Ludovic Cépré Andrew C. Stokes Geneviève Chêne
Introduction: Air pollution and social deprivation independently contribute to premature mortality. This analysis explored whether social deprivation modifies the relationship between air pollution and mortality during the period immediately preceding the COVID pandemic in hexagonal France.
Methods: A cross-sectional ecological analysis was conducted at the municipal level in hexagonal France to evaluate the associations between NO₂, PM₁₀ and PM₂.₅ average concentrations (2009-19) and mortality (2018-19), focusing on overall and premature deaths (<75 and <65 years). Three generalized negative binomial models were developed, with interaction terms for air pollution and the French Deprivation Index, as well as for longitude and latitude to adjust for spatial autocorrelation. Results are reported as Relative Rates (RR) with 95% CI for a 1 SD increase in exposure. Data were sourced from open-access repositories, including INERIS, INSEE, and CépiDc.
Results: 1,044,055 deaths were included (322,588 <75 years, 163,773 <65 years) across 34,172 municipalities (0–7,285 deaths). Higher exposure to NO₂, PM₁₀, and PM₂.₅ was associated with elevated risk of premature mortality (<75 years: RR = 1.010 (1.006-1.015); 1.019 (1.013-1.024); 1.007 (1.001-1.013); <65 years: RR = 1.012 (1.006-1.018); 1.020 (1.013-1.027); 1.008 (1.000-1.016)). NO₂ and PM₁₀ were associated with overall mortality (RR = 1.012 (1.002-1.018); 1.012 (1.008-1.016)). Social deprivation was also associated with mortality, with higher RR ranging from 1.059 (1.059-1.063) to 1.167 (1.160-1.174). Interaction analyses showed that social deprivation amplified NO₂ and PM₁₀ effects on overall mortality, and PM₂.₅ on <75 years mortality, with no significant interactions for <65 years mortality.
Conclusion: This analysis confirms that social deprivation amplifies the health risks of air pollution in hexagonal France and highlights the need for targeted interventions in disadvantaged areas to reduce health inequalities.