Air quality variations in Northern South America during the COVID-19 lockdown

Méndez-Espinosa, Juan Felipe; Rojas, Néstor Y.; Vargas, Jorge Luis Yangali; Pachón, Jorge E.; Cerón, Luis Carlos Belalcázar; Ramírez, Omar

doi:10.1016/j.scitotenv.2020.141621

Cited by 77 publications

(60 citation statements)

References 40 publications

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“…Additionally, the potential health benefits in the MCMA during the lockdown were quantified by estimated changes in the health burden ( HB) [number of premature deaths; Equation (6)] due to outdoor air pollution exposure following the methodology reported in (38,39). The averted health burden ( HB) during Phase 2 and 3 for the i-pollutant was estimated using Equations (6)(7)(8).…”

Section: Calculation Of Potential Health Benefitsmentioning

confidence: 99%

Impact of the COVID-19 Lockdown on Air Quality and Resulting Public Health Benefits in the Mexico City Metropolitan Area

Hernández‐Paniagua

Valdez

Almanza

et al. 2021

Front. Public Health

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Meteorology and long-term trends in air pollutant concentrations may obscure the results from short-term policies implemented to improve air quality. This study presents changes in CO, NO2, O3, SO2, PM10, and PM2.5 based on their anomalies during the COVID-19 partial (Phase 2) and total (Phase 3) lockdowns in Mexico City (MCMA). To minimise the impact of the air pollutant long-term trends, pollutant anomalies were calculated using as baseline truncated Fourier series, fitted with data from 2016 to 2019, and then compared with those from the lockdown. Additionally, days with stagnant conditions and heavy rain were excluded to reduce the impact of extreme weather changes. Satellite observations for NO2 and CO were used to contrast the ground-based derived results. During the lockdown Phase 2, only NO2 exhibited significant decreases (p < 0.05) of between 10 and 23% due to reductions in motor vehicle emissions. By contrast, O3 increased (p < 0.05) between 16 and 40% at the same sites where NO2 decreased. During Phase 3, significant decreases (p < 0.05) were observed for NO2 (43%), PM10 (20%), and PM2.5 (32%) in response to the total lockdown. Although O3 concentrations were lower in Phase 3 than during Phase 2, those did not decrease (p < 0.05) from the baseline at any site despite the total lockdown. SO2 decreased only during Phase 3 in a near-road environment. Satellite observations confirmed that NO2 decreased and CO stabilised during the total lockdown. Air pollutant changes during the lockdown could be overestimated between 2 and 10-fold without accounting for the influences of meteorology and long-term trends in pollutant concentrations. Air quality improved significantly during the lockdown driven by reduced NO2 and PM2.5 emissions despite increases in O3, resulting in health benefits for the MCMA population. A health assessment conducted suggested that around 588 deaths related to air pollution exposure were averted during the lockdown. Our results show that to reduce O3 within the MCMA, policies must focus on reducing VOCs emissions from non-mobile sources. The measures implemented during the COVID-19 lockdowns provide valuable information to reduce air pollution through a range of abatement strategies for emissions other than from motor vehicles.

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Section: Calculation Of Potential Health Benefitsmentioning

confidence: 99%

Impact of the COVID-19 Lockdown on Air Quality and Resulting Public Health Benefits in the Mexico City Metropolitan Area

Hernández‐Paniagua

Valdez

Almanza

et al. 2021

Front. Public Health

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“…Cities in Latin America have also recorded this reduction in air pollutants during the lockdowns motivated by the COVID-19 pandemic ( Seguel et al, 2020a ; Mendez-Espinosa et al, 2020 ), such as the metropolitan areas of Sao Paulo ( Nakada and Urban, 2020 ) and Rio de Janeiro ( Dantas et al, 2020 ; Siciliano et al, 2020 ) in Brazil and Lima-Callao in Peru ( Rojas et al, 2020 ). In Brazil, the city of Sao Paulo, under partial lockdown, showed a decrease of 65%, 77%, and 54% in the concentrations of CO, NO, and NO 2 , respectively, when compared to a 5-years monthly average.…”

Section: Introductionmentioning

confidence: 99%

Air pollution and COVID-19 lockdown in a large South American city: Santiago Metropolitan Area, Chile

et al. 2021

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The implementation of confinement and physical distancing measures to restrict people's activities and transit in the midst of the COVID-19 pandemic allowed us to study how these measures affect the air quality in urban areas with high pollution rates, such as Santiago, Chile. A comparative study between the concentrations of PM10, PM2.5, NOx, CO, and O3 during the months of March to May 2020 and the corresponding concentrations during the same period in 2017–2019 is presented. A combination of surface measurements from the air quality monitoring network of the city, remote satellite measurements, and simulations of traffic activity and road transport emissions allowed us to quantify the change in the average concentrations of each pollutant. Average relative changes of traffic emissions (between 61% and 68%) implied statistically significant concentrations reductions of 54%, 13%, and 11% for NOx, CO, and PM2.5, respectively, during the pandemic period compared to historical period. In contrast, the average concentration of O3 increased by 63% during 2020 compared to 2017–2019. The nonlinear response observed in the pollution levels can be attributed to the changes in the vehicular emission patterns during the pandemic and to the role of other sources such as residential emissions or secondary PM.

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“…Recently, a number of papers have been published reporting the changes in concentration levels for certain pollutants in different areas worldwide, where light or heavy restrictive measures have been implemented [5]. Most of these works refer to China [6][7][8], Korea [9][10][11], India [12], Central [13,14], and South-East Asia [15], but also to Western European countries [16][17][18], Africa [19,20], and North and South America [21][22][23]. The few studies related waste treatment each accounted for 1% of the total annual emissions (about 185 Gg year -1 ).…”

Section: Introductionmentioning

confidence: 99%

Regional Scale Impact of the COVID-19 Lockdown on Air Quality: Gaseous Pollutants in the Po Valley, Northern Italy

Lonati

Riva

2021

Atmosphere

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The impact of the reduced atmospheric emissions due to the COVID-19 lockdown on ambient air quality in the Po Valley of Northern Italy was assessed for gaseous pollutants (NO2, benzene, ammonia) based on data collected at the monitoring stations distributed all over the area. Concentration data for each month of the first semester of 2020 were compared with those of the previous six years, on monthly, daily, and hourly bases, so that pre, during, and post-lockdown conditions of air quality could be separately analyzed. The results show that, as in many other areas worldwide, the Po Valley experienced better air quality during 2020 spring months for NO2 and benzene. In agreement with the reductions of nitrogen oxides and benzene emissions from road traffic, estimated to be −35% compared to the regional average, the monthly mean concentration levels for 2020 showed reductions in the −40% to −35% range compared with the previous years, but with higher reductions, close to −50%, at high-volume-traffic sites in urban areas. Conversely, NH3 ambient concentration levels, almost entirely due the emissions of the agricultural sector, did not show any relevant change, even at high-volume-traffic sites in urban areas. These results point out the important role of traffic emissions in NO2 and benzene ambient levels in the Po Valley, and confirm that this region is a rather homogeneous air basin with urban area hot-spots, the contributions of which add up to a relatively high regional background concentration level. Additionally, the relatively slow response of the air quality levels to the sudden decrease of the emissions due to the lockdown shows that this region is characterized by a weak exchange of the air masses that favors both the build-up of atmospheric pollutants and the development of secondary formation processes. Thus, air quality control strategies should aim for structural interventions intended to reduce traffic emissions at the regional scale and not only in the largest urban areas.

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Air quality variations in Northern South America during the COVID-19 lockdown

Cited by 77 publications

References 40 publications

Impact of the COVID-19 Lockdown on Air Quality and Resulting Public Health Benefits in the Mexico City Metropolitan Area

Impact of the COVID-19 Lockdown on Air Quality and Resulting Public Health Benefits in the Mexico City Metropolitan Area

Air pollution and COVID-19 lockdown in a large South American city: Santiago Metropolitan Area, Chile

Regional Scale Impact of the COVID-19 Lockdown on Air Quality: Gaseous Pollutants in the Po Valley, Northern Italy

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