Spatiotemporal Variations of Air Pollution during the COVID-19 Pandemic across Tehran, Iran: Commonalities with and Differences from Global Trends (original) (raw)
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Contrasting Iran’s air quality improvement during COVID-19 with other global cities
Journal of Environmental Health Science and Engineering, 2021
Background and purpose In late 2019, a novel infectious disease (COVID-19) was identified in Wuhan China, which turned into a global pandemic. Countries all over the world have implemented some sort of lockdown to slow down its infection and mitigate it. This study investigated the impact of the COVID-19 pandemic on air quality during 1st January to 30th April 2020 compared to the same period in 2016-2019 in ten Iranian cities and four major cities in the world. Methods In this study, the required data were collected from reliable sites. Then, using SPSS and Excel software, the data were analyzed in two intervals before and after the corona pandemic outbreak. The results are provided within tables and charts. Results The current study showed the COVID-19 lockdown positively affected Iran's air quality. During the COVID-19 pandemic, the four-month mean air quality index (AQI) values in
Research Square (Research Square), 2024
The study investigated the impact of sudden frozen economy during the COVID-19 pandemic on air pollution and related health effects. The concentrations of PM10, PM2.5, SO2, O3, NO2, and CO for Air Quality Index (AQI) calculations were obtained from the Iranian Air Pollution Monitoring System in 7 provinces of central Iran between 2018 and 2021. AirQ + software was employed to estimate health risk of respiratory mortality due to O3 exposure. AQI values decreased significantly during the lockdown (39.42%) and increased after (19.09%). Comparing to 2018-2019, air pollution in 2021 decreased by: PM2.5 4.73%, PM10 0.5%, SO2 50.4%, NO2 21.16%, and CO 10.84%. However, O3 concentrations increased during lockdown by 8.2%. Mortality due to O3 exposure increased during the lockdown comparing with the baseline in 2018-2019, except for Tehran province. Death rates due to long-term exposure to ambient O3 in investigated Iranian urban areas also increased. The use of air quality and emission standards is crucial towards the reduction of adverse health impacts associated with ambient air pollution.
Impact of COVID-19 Event on the Air Quality in Iran
Aerosol and Air Quality Research, 2020
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.
Environmental Sciences Europe
Background Coronavirus disease 2019 (COVID-19) pandemic provided an opportunity for the environment to reduce ambient pollution despite the economic, social and health disruption to the world. The purpose of this study was to investigate the changes in the air quality indexes (AQI) in industrial, densely populated and capital cities in different countries of the world before and after 2020. In this ecological study, we used AQI obtained from the free available databases such as the World Air Quality Index (WAQI). Bivariate correlation analysis was used to explore the correlations between meteorological and AQI variables. Mean differences (standard deviation: SD) of AQI parameters of different years were tested using paired-sample t-test or Wilcoxon signed-rank test as appropriate. Multivariable linear regression analysis was conducted to recognize meteorological variables affecting the AQI parameters. Results AQI-PM2.5, AQI-PM10 and AQI-NO2 changes were significantly higher before a...
Environmental Science and Pollution Research, 2021
The COVID-19 pandemic has a close relationship with local environmental conditions. This study explores the effects of climate characteristics and air pollution on COVID-19 in Isfahan province, Iran. A number of COVID-19 positive cases, main air pollutants, air quality index (AQI), and climatic variables were received from March 1, 2020, to January 19, 2021. Moreover, CO, NO 2 , and O 3 tropospheric levels were collected using Sentinel-5P satellite data. The spatial distribution of variables was estimated by the ordinary Kriging and inverse weighted distance (IDW) models. A generalized linear model (GLM) was used to analyze the relationship between environmental variables and COVID-19. The seasonal trend of nitrogen dioxide (NO 2), wind speed, solar energy, and rainfall like COVID-19 was upward in spring and summer. The high and low temperatures increased from April to August. All variables had a spatial autocorrelation and clustered pattern except AQI. Furthermore, COVID-19 showed a significant association with month, climate, solar energy, and NO 2. Suitable policy implications are recommended to be performed for improving people's healthcare and control of the COVID-19 pandemic. This study could survey the local spread of COVID-19, with consideration of the effect of environmental variables, and provides helpful information to health ministry decisions for mitigating harmful effects of environmental change. By means of the proposed approach, probably the COVID-19 spread can be recognized by knowing the regional climate in major cities. The present study also finds that COVID-19 may have an effect on climatic condition and air pollutants.
Arabian Journal of Geosciences, 2021
Many countries are concerned about how concentrations of outdoor air pollutants have decreased due to control measures aftermath of the COVID-19 outbreak. In Saudi Arabia, the measures started with suspending entry to Saudi Arabia on February 27, 2020, and ended with full prevention of Saudis for outdoor movement on April 2, 2020, until the back return to normal life by the start of September 2020. These measures are expected to impact air quality levels during this period by decreasing the concentrations of air pollutants. This paper investigates the major trends of ambient air pollution (SO 2 , NO 2 , CO, O 3 , and PM 10), and maps the spatiotemporal variability of air pollutants in Makkah city, using a continuous air quality monitoring network (6 sites) during the pre-pandemic period. Findings indicate the presence of a significant decrease of concentration rates during the lockdown period, compared with the pre-pandemic period, by 26.34% for SO 2 , 28.99% for NO 2 , 26.24% for CO, 11.62% for O 3 , and 30.03% for PM 10. Therefore, the vehicular traffic activities represent 25-30% of the total air pollution load in Makkah city. The COVID-19 lockdown conditions in Makkah provide a unique opportunity to evaluate the impact of the reduction of vehicular traffic activities on the air quality levels of Makkah city and similar mega-cities and introduce credible solutions to improve the conditions of the ambient environment and air quality in such settings.
Environmental Science and Pollution Research, 2022
In the global COVID-19 epidemic, humans are faced with a new challenge. The concept of quarantine as a preventive measure has changed human activities in all aspects of life. This challenge has led to changes in the environment as well. The air quality index is one of the immediate concrete parameters. In this study, the actual potential of quarantine effects on the air quality index and related variables in Tehran, the capital of Iran, is assessed, where, first, the data on the pollutant reference concentration for all measuring stations in Tehran, from February 19 to April 19, from 2017 to 2020, are monitored and evaluated. This study investigated the hourly concentrations of six particulate matters (PM), including PM2.5, PM10, and air contaminants such as nitrogen dioxide (NO 2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO). Changes in pollution rate during the study period can be due to reduced urban traffic, small industrial activities, and dust mites of urban and industrial origins. Although pollution has declined in most regions during the COVID-19 quarantine period, the PM2.5 rate has not decreased significantly, which might be of natural origins such as dust. Next, the air quality index for the stations is calculated, and then, the interpolation is made by evaluating the root mean square (RMS) of different models. The local and global Moran index indicates that the changes and the air quality index in the study area are clustered and have a high spatial autocorrelation. The results indicate that although the bad air quality is reduced due to quarantine, major changes are needed in urban management to provide favorable conditions. Contaminants can play a role in transmitting COVID-19 as a carrier of the virus. It is suggested that due to the rise in COVID-19 and temperature in Iran, in future studies, the effect of increased temperature on COVID-19 can be assessed.
Changes in short-lived climate pollutants during the COVID-19 pandemic in Tehran, Iran
Environmental Monitoring and Assessment, 2021
In comparison to the period not affected by COVID-19 measures, mean concentrations of pollutants were increased during the first lockdown period; when the number of COVID-19 patients increased sharply compared to the other periods, the mean surface concentrations of NO 2 , SO 2 , and CO were decreased and concentrations of other pollutants (i.e., O 3 , PM 10 , and PM 2.5) were increased during the second lockdown period compared to the corresponding period in 2019. In the third period, the mean concentrations were decreased compared to the corresponding period in 2019. For the full period, decreases in mean concentrations of O 3 , NO 2 , SO 2 , CO, and PM 10 and increases in PM 2.5 were observed during the COVID-19 crisis, compared to 2019. Overall, the strongest reductions, 12% and 6%, respectively, were observed for CO and NO 2 , pointing to reduced emissions from traffic as a result of lockdown measures. The concentrations of other pollutants changed little, suggesting that the lockdown measures did not result in strong changes in the emissions from stationary sources.
Effect of short-term exposure to air pollution on COVID-19 mortality and morbidity in Iranian cities
Journal of Environmental Health Science and Engineering, 2021
Purpose The association between air pollutant (PM 2.5 , PM 10 , NO 2 , and O 3) concentrations and daily number of COVID-19 confirmed cases and related deaths were evaluated in three major Iranian cities (Tehran, Mashhad, and Tabriz). Methods Hourly concentrations of air pollutants and daily number of PCR-confirmed cases and deaths of COVID-19 were acquired (February 20 th , 2020 to January 4 th , 2021). A generalized additive model (GAM) assuming a quasi-Poisson distribution was used to model the associations in each city up to lag-day 7 (for mortality) and 14 (for morbidity). Then, the city-specific estimates were meta-analyzed using a fixed effect model to obtain the overall relative risks (RRs). Results A total of 114,964 confirmed cases and 21,549 deaths were recorded in these cities. For confirmed cases, exposure to PM 2.5 , NO 2 , and O 3 for several lag-days showed significant associations. In case of mortality, meta-analysis estimated that the RRs for
Impact of COVID-19 pandemic lockdown on air pollution in 20 major cities around the world
2020
In order to fight against the spread of COVID-19, the most hard-hit countries in the spring of 2020 implemented different lockdown strategies. To assess the impact of the COVID-19 pandemic lockdown on air quality worldwide, Air Quality Index (AQI) data was used to estimate the change in air quality in 20 major cities on six continents. Our results show significant declines of AQI in NO 2 , SO 2 , CO, PM 2.5 and PM 10 in most cities, mainly due to the reduction of transportation, industry and commercial activities during lockdown. This work shows the reduction of primary pollutants, especially NO 2 , is mainly due to lockdown policies. However, preexisting local environmental policy regulations also contributed to declining NO 2 , SO 2 and PM 2.5 emissions, especially in Asian countries. In addition, higher rainfall during the lockdown period could cause decline of PM 2.5 , especially in Johannesburg. By contrast, the changes of AQI in ground-level O 3 were not significant in most of cities, as meteorological variability and ratio of VOC/NO x are key factors in ground-level O 3 formation.