Alastuey, Andrés

Andrade, M.

Besombes, Jean-Luc

Borlaza, L. J. S.

Jaffrezo, Jean -Luc

Laj, Paolo

Mardoñez, V.

Moreno, I.

Močnik, Griša

Pandolfi, Marco

Pérez, Noemi

Uzu, G.

Weber, S.

English

Pérez, Noemí

Digital.CSIC

EGU22-6183, updated on 30 May 2023https://doi.org/10.5194/egusphere-egu22-6183EGU General Assembly 2022© Author(s) 2023. This work is distributed underthe Creative Commons Attribution 4.0 License.Sources of particulate air pollution in two high-altitude Boliviancities: La Paz and El AltoValeria Mardoñez1,2, Gaëlle Uzu1, Marcos Andrade2, Lucille Joanna S. Borlaza1, Marco Pandolfi3,Samuel Weber1, Isabel Moreno2, Jean-Luc Jaffrezo1, Jean-Luc Besombes4, Andrés Alastuey3, NoemiPerez3, Griša Močnik5, and Paolo Laj11Institute des Géosciences de l’Environnement, Université Grenoble Alpes, CNRS, IRD, Grenoble INP, Grenoble, France2Laboratorio de Física de la Atmósfera, Instituto de Investigaciones Físicas, Universidad Mayor de San Andrés, La Paz,Bolivia3Institute of Environmental Assessment and Water Research (IDAEA), CSIC, Barcelona, Spain.4Université Savoie Mont Blanc, CNRS, EDYTEM (UMR 5204), Chambéry, France5Condensed Matter Physics Department, J. Stefan Institute, Ljubljana, Slovenia.La Paz and El Alto are two high-altitude (above 3000 m.a.s.l) Bolivian cities that form part of one ofthe largest metropolitan areas in the country with a population of around 1.8 million people. Airquality in this conurbation is strongly influenced by both regional and local anthropogenic andnatural pollution sources that have not yet been studied in this region. Moreover, despite beingcontiguous cities, the drastic change in altitude and topography between them leads to differentproduction, dynamics and transport of particulate matter (PM). The need for a characterization ofthe pollutant sources in these sites lies not only in the importance of regulating the emissions toprotect public health, but also in the observed significant impact that these pollutant sourcescould have on the surrounding Bolivian glaciers. PM10was collected onto 24-h filters at twobackground stations located in La Paz and El Alto between April 2016 and June 2017. The US-EPAPositive Matrix Factorization (PMF v.5.0) receptor model was applied for apportioning the sourcesthat affect air quality in the two cities. This is the first source apportionment study in SouthAmerica that incorporates a large set of organic markers (such as levoglucosan, PAH's, Hopanesand Alkanes) together with inorganic species. The multisite PMF allowed to resolve 11 mainsources. The largest annual contribution to PM10came from 2 major sources: The ensemble ofvehicular emissions, responsible for 30.3% of the measured mass (gasoline-like-powered vehicles:16.0%; diesel-like-powered vehicles: 7.8%; non-exhaust emissions: 3.8%; Lubricant oil: 2.7%) andMineral Dust contributing 29.7% to the total PM10mass. Other 21.9% was attributed to factorsassociated to secondary aerosols (NO3-rich: 6.6%; SO4-rich: 9.8%; MSA-rich: 5.5%). Agriculture-related smoke from biomass burning originated in the lowlands in the country and neighbouringcountries contributed to 7.6% of the total PM10mass annually, this contribution doubled at theend of the biomass burning season. Primary biogenic emissions, on their side, were responsiblefor 6.3% of the measured PM10mass. Finally, it was possible to identify a profile related to openwaste burning happening between the months of May and August. Despite the fact that thissource contributed with only 4.6% to the total PM10mass, it constitutes the second-largest sourceof PAHs, compounds potentially hazardous for health. Running a multisite-PMF at these two highaltitude sites, not only provided more robustness to the model, but also led to the dissociation ofthe found traffic profile into two separate vehicular sources, one for diesel and one for gasoline-powered vehicles. This study demonstrates that PM10concentrations in this Bolivian region aremostly impacted by a limited number of local sources, which is different to what is observed inmany European urban areas. We conclude that traffic emissions and biomass burning are themain sources to target in order to improve air quality in both cities. Our results highlight the needfor dedicated studies of air pollution in high altitude regions of South America and can serve asthe start of such investigations.Powered by TCPDF (www.tcpdf.org)

Sources of particulate air pollution in two high-altitude Bolivian cities: La Paz and El Alto

https://digital.csic.es/bitstream/10261/309978/1/EGU22-6183-print.pdf

Sources of particulate air pollution in two high-altitude Bolivian cities: La Paz and El Alto

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