Spatio-temporal modeling for Nitrogen oxides pollutants in Tehran, 2014

Abstract

Background and Objectives: Annually about 7 million premature deaths occur due to air pollution in the world. Nitrogen oxides are among major air pollutants. Although many foreign exposure assessment studies have been carried out, Iranian studies are limited to primary analyses. Hence, in this research, we studied spatial variation of nitrogen oxides using spatiotemporal modeling in Tehran 2014. Methods: The concentration of nitrogen oxides was obtained from 21 air pollution monitoring stations in Tehran. There were 8760 records for each pollutant in each station. Holidays and land elevation were the predictors implemented in the spatiotemporal model. The D-STEM software was used for analyses and mapping. Results: Nitrogen monoxide significantly decreased (P<0.001) over holidays and with an increase in land elevation (coefficient:-0.070 and-0.169, respectively). Moreover, the concentration of nitrogen dioxides decreased in holidays (coefficient:-0.630) but increased with with an increase in land elevation (coefficient: 0.155) (P<0.001). Conclusion: Spatiotemporal exposure assessment of nitrogen oxide pollutants was done for residents of Tehran for the first time in this study. The results of this study, which are estimation maps for daily nitrogen oxides, could benefit future epidemiological studies in evaluation of the effect of air pollutions on health of Tehran citizens. © 2018, Iranian Epidemiological Association. All rights reserved.