**3. Results**

### *3.1. Description of the Study Area and the Population*

A total of 82,117 deaths of people over 30 were registered in Paris between January 2004 and December 2009 (and 40,710 deaths between January 2007 and December 2009). The yearly average of NO2 concentrations was 53.4 μg/m<sup>3</sup> (min = 38.6 μg/m3; max = 83.13 μg/m3). The yearly average of PM10 concentrations was 31.07μg/m<sup>3</sup> (min = 24.4μg/m3; max = 43.3 μg/m3) and 20.9 μg/m<sup>3</sup> (min = 14.9 μg/m3; max = 28.7 μg/m3) for PM2.5. The spatial distribution of the NO2 concentrations (Figure 1) shows a gradient from the south of the Seine River, with lower levels (the majority of the census blocks exhibit values less than 51 μg/m3), to the north, with higher levels (several of the census blocks, in dark colors, show values greater than 55 μg/m3). The spatial distributions of the annual average level of NO2, PM10 and PM2.5 exceeded the WHO threshold presented a similar pattern to the NO2 spatial distribution (see Appendix A Figures A1–A3). The spatial distribution of the socioeconomic index (Figure 2) revealed a clear gradient from southwest (the least deprived areas), to northeast (the most deprived areas).

**Figure 1.** Spatial distribution of the annual average NO2 concentrations according to the deciles of its distribution, at the census block level, Paris city (Period: 2004–2009).

**Figure 2.** Spatial distribution of the socioeconomic deprivation index according to the decile of its distribution, at the census block level, Paris city.
