A geostatistical approach for assessing population exposure to NO2 in a complex urban area (Beirut, Lebanon).

Nada Badaro-Saliba (1) , Jocelyne Adjizian-Gérard (2, 3) , Rita Zaarour (3) , Maher Abboud (4) , Wehbeh Farah (4) , Najat Aoun Saliba (5) , Alan L Shihadeh (6)

1 Département de Géographie
2 EDYTEM - Environnements, Dynamiques et Territoires de Montagne
3 Geography Department, Université Saint Joseph
4 Physics Department, Universite Saint Joseph
5 Chemistry Department, American University of Beirut
6 Mechanical Engineering, American University of Beirut

Few studies in the Middle East region estimated the spatial distribution of air pollutants for exposure studies. This paper presents a geostatistical approach to assess background NO2 spatial distribution and the associated exposed population in a Mediterranean city with a complex topography, Beirut. Such modeling gave an accurate mapping of the 2010 yearly background average value of NO2: it varies between 35 and 67 μg m−3 with a mean of 53 μg m−3. The mean SD of the estimated error was about 3 μg m−3. The results showed that the spatial distribution of NO2 follows a nested structuring, with a major structure related to topoclimatic characteristics (interaction topography/atmospheric flow at large scale) and a minor one linked to micro-environment and micro-climatic characteristics (interactions urban morphology/atmospheric flows at fine scale). The probability for the city's inhabitants to be exposed to NO2 levels exceeding 40 μg m−3 threshold limit set by the World Health Organization (WHO) showed that Beirut city has a real sanitary risk to the NO2 pollution. 93 % of the population (around 358,459 people) is 100 % sure to be exposed to a yearly average exceeding 40 μg m−3. This knowledge will be certainly useful for developing a tool for decision support in order to implement policies of reducing air pollution in Beirut, which is, given the results, very urgent.

Nada Badaro-Saliba, Jocelyne Adjizian-Gérard, Rita Zaarour, Maher Abboud, Wehbeh Farah, et al.. A geostatistical approach for assessing population exposure to NO2 in a complex urban area (Beirut, Lebanon).. Stochastic Environmental Research and Risk Assessment, 2013, 8p. ⟨10.1007/s00477-013-0765-3⟩. ⟨halsde-00879992⟩