Departamento de Ciencias Básicas
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- Quantification of primary PM₂.₅ Mass Exchange in three Mexican Megalopolis Metropolitan Areas(Elsevier, 2023-07-08) HERNANDEZ-MORENO, ADOLFO; Trujillo-Páez, Fátima I.; Mugica-Alvarez, VioletaIt is commonly assumed that the outgoing flux of pollutants from large cities deteriorates the air quality of neighboring communities. Quantifying the mass exchange of pollutants among cities will enable local and regional planning of environmental management programs, to identify well all previously unrecognized impacted areas. In this study, the quantification of outgoing and incoming fluxes of primary PM₂.₅ particle mass among three neighboring metropolitan areas of the Mexico City Megalopolis in the dry-cold climate months, was carried out for the first time. The results show that the metropolitan areas of Toluca Valley and Cuernavaca receive mass quantities of PM₂.₅ approximately equivalent to a 100% of their local emissions. The prevailing winds in the cold-dry climate months, impel the emissions from the studied metropolitan areas, effectually dispersing in different directions, though mainly towards the megalopolis South, impacting with large mass amounts of PM₂.₅ the rural areas. The overlap puffs of local emissions with imported particle masses contribute to atypically high concentration events in receiving metropolitan areas. In the import-export balance, the metropolitan areas of Toluca and Cuernavaca had a significant PM₂.₅ concentration increasing during the cold-dry climate months mainly due to the incoming particles from the Mexico City Metropolitan Area.
- Atmospheric Estrogenic Semi-Volatile Compounds and PAH in PM₂.₅ in Mexico City(MDPI, 2025-02-05) Ronderos, Gustavo; Millán Vázquez, Fernando; Murillo Tovar, Mario; Saldarriaga Noreña, Hugo; Valle-Hernández, Brenda L; López-Velázquez, Khirbet; Mugica-Alvarez, VioletaThe quantification of semi-volatile organic compounds with potential endocrinedisrupting activity contained in fine atmospheric particles (PM₂.₅) is essential to understand their temporal behavior, identify their sources, and evaluate the health risks resulting from population exposure to said compounds. Since information and research outcomes regarding their presence in the atmosphere in developing countries are scarce, the main objective of this work was the development of a methodology devoted to extracting, characterizing, and quantifying, for the first time in Mexico, the concentration levels of three important groups of endocrine-disrupting compounds (EDCs) bonded to PM₂.₅ and collected during a year, namely: alkylphenols (4-n-nonylphenol (4NP) and 4-tert-octylphenol (4tOP)); bisphenols (bisphenol A (BPA) and bisphenol F (BPF)); natural and synthetic hormones (17β-estradiol (E₂), estriol (E₃) and 17α-ethinyl estradiol (EE₂)). Further, priority polycyclic aromatic hydrocarbons (PAH) that also disrupt endocrine activity were analyzed. All compounds were determined by gas chromatography coupled to tandem mass spectrometry, and the concentration levels were analyzed for different climatic seasons. Cold-dry (CD) season displayed higher levels of 4NP, bisphenols, and hormones (between 0.71 (4NP) and 1860 pg m-³ (BPA)), as well as PAH concentrations (9.12 ng m-³). Regarding health effects, concentrations of alkylphenols, bisphenols, and hormones quantified had a value of estradiol equivalent concentration (EEQE2) between 0.07 and 0.17 ng m-³. PAH concentrations did not have carcinogenic and mutagenic risk with BaP(PEQ) < 1 ng m-³. These results can be used by policymakers in the design of strategies for air pollution control.
- Morphological and chemical composition of PM₂.₅ emissions from a concrete factory in Toluca, México(Atena Editora, 2024) SANTIAGO CRUZ, YANET; Sánchez Meza, Juan Carlos; Amaya Chávez, Araceli; Cruz-Núñez, Xochitl; Mugica-Alvarez, VioletaThe concrete industry is known to produce PM₂.₅ emissions in various production stages. This study analyzes PM₂.₅ emissions originating from a readymix concrete factory situated in the Toluca Valley Metropolitan Zone (MZTV) in central Mexico. Samples were collected over different seasons – warm dry, rainy, and cold dry – using a low-volume particle analyzer. The samples were subsequently analyzed to determine, the morphology by Scanning Electron Microscopy (SEM), elemental chemical composition by Energy Dispersion (EDS). The analysis revealed that the concentration of PM₂.₅ emissions exceeded permissible limits, posing significant health risks. The chemical composition of the PM₂.₅ emissions were analyzed, revealing that they mainly comprised O, C, Si, Fe, Ca, Al, K, and Na, which are consistent with Portland cement. The study emphasizes the need for strict environmental controls and tailored management strategies to mitigate the impact of emissions on human health. It also highlights the significant influence of meteorological conditions, which affect particulate dispersion. Finally, in this contribution, the authors aim to better understand the effects of PM₂.₅ emissions originating from the concrete industry providing insight into the need for stringent environmental regulations.
- Air Pollution and Climate Change Risk Perception among Residents in Three Cities of the Mexico Megalopolis(MDPI, 2023-12-29) LANDEROS-MUGICA, KARINA; URBINA-SORIA, JAVIER; Angeles Hernández , Diana Isabel ; Gutiérrez-Arzaluz, Mirella; Mugica-Alvarez, VioletaRecent reports of the criteria pollutants in the Megalopolis, located in the central part of Mexico, consistently show air quality standard exceedances in most of the cities that make it up, since it is a large concentration where approximately 17% of the national population resides and because it has significant commercial and industrial development. To investigate the similarities and disparities in risk perception concerning air pollution and climate change among residents living in Central Mexico, a cross-sectional survey study was carried out within three metropolitan areas encompassed by the Megalopolis. A total of 1750 questionnaire surveys were conducted across 21 municipalities within the Mexico City Metropolitan Area (MCMA), 16 municipalities within the Toluca Valley Metropolitan Area (TVMA), and 8 municipalities within the Cuernavaca Metropolitan Area. The three metropolitan areas showed significant differences in terms of air quality perception, risk perception, attitudes, and causal attribution perception, but health-related perception did not have significant differences among the areas. The MCMA exhibited higher knowledge about air pollution, although it associated the causes with urban activities such as car usage, while the Toluca and Cuernavaca areas linked this issue to the burning of garbage, coal, wood, and agricultural activities. Although residents expressed concern about air pollution, climate change, and their effects, they do not know how to act to contribute to the solution.
- Temporal Variation and Potential Sources of Water-Soluble Inorganic Ions in PM₂.₅ in Two Sites of Mexico City(MDPI, 2023-10-20) Millán-Vázquez, Fernando; Sosa Echeverría, Rodolfo; Alarcón Jiménez, Ana Luisa; Figueroa-Lara, José de Jesús; Torres Rodriguez, Miguel; Valle-Hernández, Brenda L; Mugica Álvarez, VioletaThis study presents the characterization and source apportionment of water-soluble inorganic ions (WSII), contained in particulate matter with an aerodynamic diameter equal to or less tan 2.5 µm (PM₂.₅), performed using the positive matrix factorization model (PMF). PM₂.₅ were collected in Mexico City from two sites: at Merced (MER), which is a residential location with commercial activities, and at Metropolitan Autonomous University (UAM), which is located in an industrial area. The monitoring campaign was carried out across three seasons named Hot Dry (HD) (March–June), Rain (RA) (July–October), and Cold Dry (CD) (November-February). PM₂.₅ concentration behavior in both sites was similar, following the order: CD > HD > RA. The UAM site exhibited higher concentrations of PM₂.₅, of the five cations (Na+, Mg²+, Ca², K+ and NH₄ +), and of the four anions (Cl-, SO₄ ²-, NO₃ - and PO₄ ³-) than MER, since the UAM site is surrounded by several industrial zones. PM₂.₅ average concentrations for UAM and MER were 28.4 ± 11.2 and 20.7 ± 8.4 µg m-³, respectively. The ratio of cation equivalent to anion equivalent (CE/AC) showed that aerosol pH is acidic, which was confirmed by direct pH measurements. The sulfur oxidation rate (SOR) was 20 times larger than the nitrogen oxidation rate (NOR). Additionally, SO₄²- was the most abundant ion during the whole year, especially during the CD season with 5.13 ± 2.5 µg m-³ and 4.9 ± 3.6 µg m-³ for UAM and MER, respectively, when solar radiation displayed a high intensity. On the opposite side, the conversion of NO₂ to NO³-, respectively, was low. The air mass backward trajectories were modeled using the National Oceanic and Atmospheric Administration (NOAA-HYSPLIT), which allowed us to know that differences in the mass trajectories during the days with higher concentrations were due to an effect of air recirculation, which favored PM₂.₅ accumulation and resuspension. On the other hand, on the days with less PM₂.₅, good air dispersion was observed. The main sources identified with the PMF model were secondary aerosol, vehicular, industrial crustal, and biomass burning for UAM, while for MER they were vehicular, secondary aerosol, and crustal.