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. 2020 Jul 15:726:138540.
doi: 10.1016/j.scitotenv.2020.138540. Epub 2020 Apr 11.

Changes in air quality during the lockdown in Barcelona (Spain) one month into the SARS-CoV-2 epidemic

Aurelio Tobías  1 , Cristina Carnerero  2 , Cristina Reche  2 , Jordi Massagué  2 , Marta Via  2 , María Cruz Minguillón  2 , Andrés Alastuey  2 , Xavier Querol  3
Affiliations

Changes in air quality during the lockdown in Barcelona (Spain) one month into the SARS-CoV-2 epidemic

Aurelio Tobías et al. Sci Total Environ. .

Abstract

Lockdown measures came into force in Spain from March 14th, two weeks after the start of the SARS-CoV-2 epidemic, to reduce the epidemic curve. Our study aims to describe changes in air pollution levels during the lockdown measures in the city of Barcelona (NE Spain), by studying the time evolution of atmospheric pollutants recorded at the urban background and traffic air quality monitoring stations. After two weeks of lockdown, urban air pollution markedly decreased but with substantial differences among pollutants. The most significant reduction was estimated for BC and NO2 (-45 to -51%), pollutants mainly related to traffic emissions. A lower reduction was observed for PM10 (-28 to -31.0%). By contrast, O3 levels increased (+33 to +57% of the 8 h daily maxima), probably due to lower titration of O3 by NO and the decrease of NOx in a VOC-limited environment. Relevant differences in the meteorology of these two periods were also evidenced. The low reduction for PM10 is probably related to a significant regional contribution and the prevailing secondary origin of fine aerosols, but an in-depth evaluation has to be carried out to interpret this lower decrease. There is no defined trend for the low SO2 levels, probably due to the preferential reduction in emissions from the least polluting ships. A reduction of most pollutants to minimal concentrations are expected for the forthcoming weeks because of the more restrictive actions implemented for a total lockdown, which entered into force on March 30th. There are still open questions on why PM10 levels were much less reduced than BC and NO2 and on what is the proportion of the abatement of pollution directly related to the lockdown, without meteorological interferences.

Keywords: Lockdown; NO(2); Ozone; Particulate matter; SARS-CoV-2; SO(2).

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Conflict of interest statement

Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Figures

Unlabelled Image
Graphical abstract
Fig. 1
Fig. 1
Daily (24 h) average concentrations of PM10, BC, NO2, SO2, and 8 h average daily maxima of O3 between February 16th and March 30th (with lockdown on March 14th) in Barcelona, Spain (in highlighted shadow those days with Saharan intrusion).
Fig. 2
Fig. 2
Average levels of background tropospheric NO2 measured by TROPOMI-ESA in the Iberian Peninsula. Bottom-left panel: between February 16th to March 13th, 2020 (before the lockdown); bottom-right: March 14th to March 30th, 2020 (during the lookdown). Top panel: equivalent time periods in 2019.
See this image and copyright information in PMC

References

    1. Amato F., Alastuey A., Karanasiou A., Lucarelli F., Nava S., Calzolai G. AIRUSE-LIFE+: a harmonized PM speciation and source apportionment in five southern European cities. Atmos. Chem. Phys. 2016;16:3289–3309.
    1. Gorelick N., Hancher M., Dixon M., Ilyushchenko S., Thau D., Moore R. Google earth engine: planetary-scale geospatial analysis for everyone. Remote Sens. Environ. 2017;202:18–27.
    1. Ministerio de la Presidencia, Relaciones con las Cortes y Memoria Democrática (MPRCMD) . Real Decreto 463/2020de 14 de marzo, por el que se declara el estado de alarma para la gestión de la situación de crisis sanitaria ocasionada por el COVID-19. 2020. https://www.boe.es/eli/es/rd/2020/03/14/463/con Available from:
    1. Ministerio de la Presidencia, Relaciones con las Cortes y Memoria Democrática (MPRCMD) . Real Decreto-ley 10/2020, de 29 de marzo, por el que se regula un permiso retribuido recuperable para las personas trabajadoras por cuenta ajena que no presten servicios esenciales, con el fin de reducir la movilidad de la población en el contexto de la lucha contra el COVID-19. 2020. https://www.boe.es/buscar/doc.php?id=BOE-A-2020-4166 [Accessed 31 Mar 2020]. Available from:
    1. Ministerio para la Transición Ecológica y el Reto Demográfico (MITECO). African dust alert system. 2020. https://www.miteco.gob.es/es/calidad-y-evaluacion-ambiental/temas/atmosf... [Accessed 31 Mar 2020]. Available from: