Effects of the COVID-19 Pandemic on the Air Quality of the Metropolitan Region of São Paulo: Analysis Based on Satellite Data, Monitoring Stations and Records of Annual Average Daily Traffic Volumes on the Main Access Roads to the City

Abstract

This paper presents an analysis of the effects of the COVID-19 pandemic on the air quality of the Metropolitan Region of São Paulo (MRSP). The effects of social distancing are still recent in the society; however, it was possible to observe patterns of environmental changes in places that had adhered transportation measures to combat the spread of the coronavirus. Thus, from the analysis of the traffic volumes made on some of the main access highways to the MRSP, as well as the monitoring of the levels of fine particulate matter (PM2.5), carbon monoxide (CO) and nitrogen dioxide (NO2), directly linked to atmospheric emissions from motor vehicles–which make up about 95% of air polluting agents in the region in different locations–we showed relationships between the improvement in air quality and the decrease in vehicles that access the MRSP. To improve the data analysis, therefore, the isolation index parameter was evaluated to provide daily information on the percentage of citizens in each municipality of the state that was effectively practicing social distancing. The intersection of these groups of data determined that the COVID-19 pandemic reduced the volume of vehicles on the highways by up to 50% of what it was in 2019, with the subsequent recovery of the traffic volume, even surpassing the values from the baseline year. Thus, the isolation index showed a decline of up to 20% between its implementation in March 2020 and December 2020. These data and the way they varied during 2020 allowed to observe an improvement of up to 50% in analyzed periods of the pollutants PM2.5, CO and NO2 in the MRSP. The main contribution of this study, alongside the synergistic use of data from different sources, was to perform traffic flow analysis separately for light and heavy duty vehicles (LDVs and HDVs). The relationships between traffic volume patterns and COVID-19 pollution were analyzed based on time series.

Effects of Mobility Restrictions on Air Pollution in the Madrid Region during the COVID-19 Pandemic and Post-Pandemic Periods

“…This reduction in the number of vehicles that were circulating on the streets matches the reduction in air pollution we calculated for the periods when the mobility restrictions were in full force. This phenomenon is also observed in studies conducted by Rossi et al (2020) [31], Baldasano (2020) [10], and Pérez-Martínez et al (2022) [54] in other European cities.…”

“…The contribution of the study is threefold and was addressed in previous studies: (i) to analyze the changes in Many studies were published since 2020 analyzing the impacts of strict lockdowns on air pollution in urban areas (see review studies conducted by Gkatzelis et al (2021) [49] and Silva et al (2022) [50]). Focusing on Spanish urban areas, some authors made direct comparisons between pollutant concentrations in the lockdown period vs. the pre-COVID-19 period in cities such as Madrid and Barcelona [10,12,[51][52][53][54]. At the international level, Gualtieri et al [58], among others, used the same methodology to analyse in detail the impacts of traffic reduction on air quality during the COVID-19 lockdown.…”

Is Yogyakarta City Worthy of Waste-Based Energy Development?

“…Applying social restrictions and working from home in various parts of the world can reduce pollution levels in the highest air-polluting countries [18]. The quarantine policy is allegedly improving air quality in several areas.…”

Changes in healthy effects and economic burden of PM2.5 in Beijing after COVID-19

“…The impact of the COVID-19 epidemic on the global urban environment is enormous. During the COVID-19 pandemic, the number of vehicles on highways in the Metropolitan Region of São Paulo (MRSP), Brazil, decreased by 50% compared to 2019, and air quality improved significantly (Perez-Martinez et al 2022). During the outbreak lockdown, both indoor and ambient PM levels in Chennai, India, were significantly reduced (Puttaswamy et al 2022).…”