16 Mar Lessons from the COVID-19 air pollution decrease in Spain: Now what?
Title: Lessons from the COVID-19 air pollution decrease in Spain: Now what?
Authors: Xavier Querola, Jordi Massaguéa,b, Alastueya, Teresa Morenoa, Gotzon Gangoitic, Enrique Mantillad, José Jaime Duéguezd, Miguel Escuderoe, Eliseo Monfortf, Carlos Pérez García-Pandog,h, Hervé Peteting, Oriol Jorbag, Víctor Vázquezi,j, Jesús de la Rosak, Alberto Camposl, Marta Muñózl, Silvia Mongel, María Hervásl, Rebeca Javatol, María J. Cornidel
Journal: Science of the Total Environment
a Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Barcelona, 08034, Spain
b Department of Mining, Industrial and ICT Engineering, Universitat Politècnica de Catalunya – BarcelonaTech (UPC), Manresa, 08242, Spain
c Department of Chemical and Environmental Engineering, University of Basque Country, Leioa, 48940, Spain
d Centro de Estudios Ambientales del Mediterráneo, CEAM, València, 46980, Spain
e Centro Universitario de la Defensa, Academia General Militar, Zaragoza, 50090, Spain
f Instituto de Tecnología Cerámica ITC-UJI, Castelló, 12006, Spain
g Barcelona Supercomputing Center, BSC-CNS, Barcelona, 08034, Spain
h ICREA, Catalan Institution for Research and Advanced Studies, Barcelona, 08010, Spain
i Department of Ecology, Faculty of Sciences, University of Málaga, 29071, Málaga, Spain
j Department of Research and Development, Coccosphere Environmental Analysis, C/Cruz 39, 29120 Alhaurín el Grande, Málaga, Spain
k Department of Geology, University of Huelva, Huelva, 21819, Unidad de Investigación Associada a IDAEA-CSIC, Spain
l D.G. Calidad y Evaluación Ambiental del Ministerio de Transición Ecológica y Reto demográfico, Madrid, 28071, Spain
We offer and overview of the COVID-19 -driven air quality changes across 11 metropolises in Spain with the focus on lessons learned on how continuing abating pollution. Traffic flow decreased by up to 80% during the lockdown and remained relatively low during the full relaxation (June and July). After the lockdown a significant shift from public transport to private vehicles (+21% in Barcelona) persisted due to fair to infection, which need to be reverted as soon as possible. NO2 levels fell below 50% of the WHO annual air quality guidelines (WHOAQGs), but PM2.5 were reduced less than expected due to its lower contributions from traffic, increased contributions from agricultural and domestic biomass burning, or large secondary aerosol contributions. Even during the lockdown, the annual PM2.5 WHOAQG was exceeded in cities within the NE and E regions with high NH3 emissions from farming and agriculture. Decreases in PM10 levels were greater than in PM2.5 due to reduced emissions from road dust, vehicle wear, and construction/demolition activities. Averaged O3 daily maximum 8-hours (8hDM) experienced a generalized decrease in the rural receptor sites in the relaxation (June-July) with -20% reduced mobility. For urban areas O3 8hDM responses were heterogeneous, with increases or decreases depending on the period and location. Thus, after cancelling out the effect of meteorology, 5 out of 11 cities experienced O3 decreases during the lockdown, while the remaining 6 either did not experience relevant reductions or increased. During the relaxation period and coinciding with the growing O3 season (June-July), most cities experienced decreases. However, the O3 WHOAQG was still exceeded during the lockdown and full relaxation periods in several cities For secondary pollutants such as O3, further chemical and dispersion modeling along with source apportionment techniques to identify major precursor reduction targets are required to evaluate the O3 abatement potential.