Spatial modelling of the NO2 concentrations in the city of Madrid (Spain): application of the action protocol

Air pollution in cities is a significant environmental concern impacting public health. Local authorities are adapting their policies to balance well-being, transport services and industrial activities. This study aims to quantitatively assess the unequal distribution of NO2 in different districts of Madrid. The Ordinary Kriging geostatistical method is applied to spatially and temporally assess the impact of the NO2 and rainfall. The resulting point clusters revealed that there are two areas exceeding the established annual limits (40 mu g/m(3)), which implies that they are highly vulnerable to NO2 pollution: the City Centre and the SW area on the urban outskirts of Madrid. Both areas require more intensive air quality monitoring. In addition, other influential parameters were characterized for each cluster, i.e., traffic intensity, population density and green areas. In conclusion, these areas necessitate increased control and monitoring to mitigate the health risks associated with air pollution.