Impact of COVID-19 Event on the Air Quality in Iran

Parya Broomandi ； Ferhat Karaca ； Amirhossein Nikfal ； Ali Jahanbakhshi ； Mahsa Tamjidi ； Jong Ryeol Kim

《Aerosol and Air Quality Research》 20卷8期 (2020/08) Pp. 1793-1804

https://doi.org/10.4209/aaqr.2020.05.0205

摘要

The first novel coronavirus case was confirmed in Iran in mid-February 2020. This followed by the enforcement of lockdown to tackle this contagious disease. This study aims to examine the potential effects of the COVID-19 lockdown on air quality in Iran. From 21^(st) March to 21^(st) April in 2019 and 2020, The Data were gathered from 12 air quality stations to analyse six criteria pollutants, namely O_3, NO_2, SO_2, CO, PM_(10), and PM_(2.5). Due to the lack of ground-level measurements, using satellite data equipped us to assess changes in air quality during the study on Iranian megacities, especially in Tehran, i.e., the capital of Iran. In this city, concentrations of primary pollutants (SO_2 5-28%, NO_2 1-33%, CO 5-41%, PM_(10) 1.4-30%) decreased with spatial variations. Although, still SO_2, NO_2, and PM_(10) exceeded the WHO daily limit levels for 31 days, 31 days, and four days, respectively. Conversely, O_3 and PM_(2.5) increased by 0.5-103% and 2-50%. In terms of the national air quality, SO_2 and NO_2 levels decreased while AOD increased during the lockdown. Unfavourable meteorological conditions hindered pollutant dispersion. Moreover, reductions in the height of planetary boundary layer and rainfall were observed during the lockdown period. Despite the adverse weather conditions, a decrease in primary pollutant levels, confirms the possible improvements on the air quality in Iran.

關鍵字

SARS-CoV-2 ； Atmospheric pollution ； Lockdown ； Tehran ； Nitrogen dioxide ； Carbon monoxide