Browsing by Autor "Lucille Joanna S. Borlaza"

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Comment on acp-2022-780
(2023) Valeria MardoÃ±ez; Marco Pandolfi; Lucille Joanna S. Borlaza; Jean‐Luc Jaffrezo; AndrÃ©s Alastuey; Jean‐Luc Besombes; Isabel Moreno; Noemí Pérez; GriÅ¡a MoÄ nik; Patrick Ginot
Abstract. La Paz and El Alto are two fast-growing high-altitude Bolivian cities forming the second largest metropolitan area in the country, located between 3200 and 4050 m a.s.l. Together they host a growing population of around 1.8 million people. The air quality in this conurbation is strongly influenced by urbanization. However, there are no comprehensive studies that have assessed the sources of air pollution and their impacts on health. Despite being neighboring cities, the drastic change in altitude and topography between La Paz and El Alto together with different socio-economic activities lead to different sources, dynamics and transport of particulate matter (PM). In this investigation, PM10 samples were collected at two urban background stations located in La Paz and El Alto between April 2016 and June 2017. The samples were later analyzed for a wide range of chemical species including numerous source tracers (OC, EC, water-soluble ions, sugar anhydrides, sugar alcohols, trace metals, and molecular organic species). The US-EPA Positive Matrix Factorization (PMF v.5.0) receptor model was then applied for source apportionment of PM10. This is the first source apportionment study in South America that incorporates a large set of organic markers (such as levoglucosan, polycyclic aromatic hydrocarbons – PAH, hopanes and alkanes) together with inorganic species. The multisite PMF resolved 11 main sources of PM. The largest annual contribution to PM10 came from two major sources: the ensemble of the four vehicular emissions sources (exhaust and non-exhaust), together responsible for 35 % and 25 % of the measured PM in La Paz and El Alto, respectively, and dust contributing 20 % and 32 % to the total. Secondary aerosols contributed 22 % (24 %) in La Paz (El Alto). Agriculture-related smoke from biomass burning originated in the Bolivian lowlands and neighboring countries contributed to 8 % (7 %) of the total PM10 mass annually. This contribution increased to 17 % (13 %) between August–October. Primary biogenic emissions were responsible for 13 % (7 %) of the measured PM10 mass. Finally, it was possible to identify a profile related to open waste burning occurring between the months of May and August. Despite the fact that this source contributed only to 2 % (5 %) of the total PM10 mass, it constitutes the second largest source of PAHs, compounds potentially hazardous to health. Our analysis resulted in the identification of two specific traffic-related sources. In addition, we also identified a lubricant source (not frequently identified) and a non-exhaust emissions source. This study shows that PM10 concentrations in La Paz and El Alto region are mostly impacted by a limited number of local sources. In conclusion, dust, traffic emissions, open waste burning and biomass burning are the main sources to target in order to improve air quality in both cities.
Oxidative potential of particulate matter and its association to respiratory health endpoints in high-altitude cities in Bolivia
(Elsevier BV, 2024) Lucille Joanna S. Borlaza; Valeria Mardóñez; Anouk Marsal; Ian Hough; Vy Dinh Ngoc Thuy; Pamela Dominutti; Jean‐Luc Jaffrezo; Andrés Alástuey; Jean‐Luc Besombes; Griša Močnik
Oxidative Potential of Particulate Matter and its Association to Respiratory Health Endpoints in High-Altitude Cities in Bolivia
(RELX Group (Netherlands), 2024) Lucille Joanna S. Borlaza; Valeria Mardóñez; Anouk Marsal; Ian Hough; Vy Dinh Ngoc Thuy; Pamela Dominutti; Jean‐Luc Jaffrezo; Andrés Alástuey; Jean‐Luc Besombes; Griša Močnik
Source apportionment study on particulate air pollution in two high-altitude Bolivian cities: La Paz and El Alto
(Copernicus Publications, 2023) Valeria Mardóñez; Marco Pandolfi; Lucille Joanna S. Borlaza; Jean‐Luc Jaffrezo; Andrés Alástuey; Jean‐Luc Besombes; Isabel Moreno; Noemí Pérez; Griša Močnik; Patrick Ginot
Abstract. La Paz and El Alto are two fast-growing, high-altitude Bolivian cities forming the second-largest metropolitan area in the country. Located between 3200 and 4050 m a.s.l. (above sea level), these cities are home to a burgeoning population of approximately 1.8 million residents. The air quality in this conurbation is heavily influenced by urbanization; however, there are no comprehensive studies evaluating the sources of air pollution and their health impacts. Despite their proximity, the substantial variation in altitude, topography, and socioeconomic activities between La Paz and El Alto result in distinct sources, dynamics, and transport of particulate matter (PM). In this investigation, PM10 samples were collected at two urban background stations located in La Paz and El Alto between April 2016 and June 2017. The samples were later analyzed for a wide range of chemical species including numerous source tracers (OC, EC, water-soluble ions, sugar anhydrides, sugar alcohols, trace metals, and molecular organic species). The United States Environmental Protection Agency (U.S. EPA) Positive Matrix Factorization (PMF v.5.0) receptor model was employed for the source apportionment of PM10. This is one of the first source apportionment studies in South America that incorporates an extensive suite of organic markers, including levoglucosan, polycyclic aromatic hydrocarbons (PAHs), hopanes, and alkanes, alongside inorganic species. The multisite PMF resolved 11 main sources of PM. The largest annual contribution to PM10 came from the following two major sources: the ensemble of the four vehicular emissions sources (exhaust and non-exhaust), accountable for 35 % and 25 % of the measured PM in La Paz and El Alto, respectively; and dust, which contributed 20 % and 32 % to the total PM mass. Secondary aerosols accounted for 22 % (24 %) in La Paz (El Alto). Agricultural smoke resulting from biomass burning in the Bolivian lowlands and neighboring countries contributed to 9 % (8 %) of the total PM10 mass annually, increasing to 17 % (13 %) between August–October. Primary biogenic emissions were responsible for 13 % (7 %) of the measured PM10 mass. Additionally, a profile associated with open waste burning occurring from May to August was identified. Although this source contributed only to 2 % (5 %) of the total PM10 mass, it constitutes the second largest source of PAHs, which are compounds potentially hazardous to human health. Our analysis additionally resolved two different traffic-related factors, a lubricant source (not frequently identified), and a non-exhaust emissions source. Overall, this study demonstrates that PM10 concentrations in La Paz and El Alto region are predominantly influenced by a limited number of local sources. In conclusion, to improve air quality in both cities, efforts should primarily focus on addressing dust, traffic emissions, open waste burning, and biomass burning.
Source apportionment study on particulate air pollution in two high-altitude Bolivian cities: La Paz and El Alto
(2022) Valeria Mardóñez; Marco Pandolfi; Lucille Joanna S. Borlaza; Jean‐Luc Jaffrezo; Andrés Alástuey; Jean‐Luc Besombes; Isabel Moreno; Noemí Pérez; Griša Močnik; Patrick Ginot
Abstract. La Paz and El Alto are two fast-growing high-altitude Bolivian cities forming the second largest metropolitan area in the country, located between 3200 and 4050 m a.s.l. Together they host a growing population of around 1.8 million people. The air quality in this conurbation is strongly influenced by urbanization. However, there are no comprehensive studies that have assessed the sources of air pollution and their impacts on health. Despite being neighboring cities, the drastic change in altitude and topography between La Paz and El Alto together with different socio-economic activities lead to different sources, dynamics and transport of particulate matter (PM). In this investigation, PM10 samples were collected at two urban background stations located in La Paz and El Alto between April 2016 and June 2017. The samples were later analyzed for a wide range of chemical species including numerous source tracers (OC, EC, water-soluble ions, sugar anhydrides, sugar alcohols, trace metals, and molecular organic species). The US-EPA Positive Matrix Factorization (PMF v.5.0) receptor model was then applied for source apportionment of PM10. This is the first source apportionment study in South America that incorporates a large set of organic markers (such as levoglucosan, polycyclic aromatic hydrocarbons – PAH, hopanes and alkanes) together with inorganic species. The multisite PMF resolved 11 main sources of PM. The largest annual contribution to PM10 came from two major sources: the ensemble of the four vehicular emissions sources (exhaust and non-exhaust), together responsible for 35 % and 25 % of the measured PM in La Paz and El Alto, respectively, and dust contributing 20 % and 32 % to the total. Secondary aerosols contributed 22 % (24 %) in La Paz (El Alto). Agriculture-related smoke from biomass burning originated in the Bolivian lowlands and neighboring countries contributed to 8 % (7 %) of the total PM10 mass annually. This contribution increased to 17 % (13 %) between August–October. Primary biogenic emissions were responsible for 13 % (7 %) of the measured PM10 mass. Finally, it was possible to identify a profile related to open waste burning occurring between the months of May and August. Despite the fact that this source contributed only to 2 % (5 %) of the total PM10 mass, it constitutes the second largest source of PAHs, compounds potentially hazardous to health. Our analysis resulted in the identification of two specific traffic-related sources. In addition, we also identified a lubricant source (not frequently identified) and a non-exhaust emissions source. This study shows that PM10 concentrations in La Paz and El Alto region are mostly impacted by a limited number of local sources. In conclusion, dust, traffic emissions, open waste burning and biomass burning are the main sources to target in order to improve air quality in both cities.
Sources of particulate air pollution in two high-altitude Bolivian cities: La Paz and El Alto
(2022) Valeria Mardóñez; Gaëlle Uzu; Marcos Andrade; Lucille Joanna S. Borlaza; Marco Pandolfi; Samuël Weber; Isabel Moreno; Jean‐Luc Jaffrezo; Jean‐Luc Besombes; Andrés Alástuey
&lt;p&gt;La Paz and El Alto are two high-altitude (above 3000 m.a.s.l) Bolivian cities that form part of one of the largest metropolitan areas in the country with a population of around 1.8 million people. Air quality in this conurbation is strongly influenced by both regional and local anthropogenic and natural pollution sources that have not yet been studied in this region. Moreover, despite being contiguous cities, the drastic change in altitude and topography between them leads to different production, dynamics and transport of particulate matter (PM). The need for a characterization of the pollutant sources in these sites lies not only in the importance of regulating the emissions to protect public health, but also in the observed significant impact that these pollutant sources could have on the surrounding Bolivian glaciers. PM&lt;sub&gt;10&lt;/sub&gt; was collected onto 24-h filters at two background stations located in La Paz and El Alto between April 2016 and June 2017. The US-EPA Positive Matrix Factorization (PMF v.5.0) receptor model was applied for apportioning the sources that affect air quality in the two cities. This is the first source apportionment study in South America that incorporates a large set of organic markers (such as levoglucosan, PAH's, Hopanes and Alkanes) together with inorganic species. The multisite PMF allowed to resolve 11 main sources. The largest annual contribution to PM&lt;sub&gt;10&lt;/sub&gt; came from 2 major sources: The ensemble of vehicular 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%) and Mineral Dust contributing 29.7% to the total PM&lt;sub&gt;10&lt;/sub&gt; mass. Other 21.9% was attributed to factors associated to secondary aerosols (NO&lt;sub&gt;3&lt;/sub&gt;-rich: 6.6%; SO&lt;sub&gt;4&lt;/sub&gt;-rich: 9.8%; MSA-rich: 5.5%). Agriculture-related smoke from biomass burning originated in the lowlands in the country and neighbouring countries contributed to 7.6% of the total PM&lt;sub&gt;10&lt;/sub&gt; mass annually, this contribution doubled at the end of the biomass burning season. Primary biogenic emissions, on their side, were responsible for 6.3% of the measured PM&lt;sub&gt;10&lt;/sub&gt; mass. Finally, it was possible to identify a profile related to open waste burning happening between the months of May and August. Despite the fact that this source contributed with only 4.6% to the total PM&lt;sub&gt;10&lt;/sub&gt; mass, it constitutes the second-largest source of PAHs, compounds potentially hazardous for health. Running a multisite-PMF at these two high altitude sites, not only provided more robustness to the model, but also led to the dissociation of the found traffic profile into two separate vehicular sources, one for diesel and one for gasoline-powered vehicles. This study demonstrates that PM&lt;sub&gt;10&lt;/sub&gt; concentrations in this Bolivian region are mostly impacted by a limited number of local sources, which is different to what is observed in many European urban areas. We conclude that traffic emissions and biomass burning are the main sources to target in order to improve air quality in both cities. Our results highlight the need for dedicated studies of air pollution in high altitude regions of South America and can serve as the start of such investigations.&lt;/p&gt;