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  1. Article ; Online: Human health risk assessment of PM

    Arregocés, Heli A / Bonivento, Guillermo J / Ladino, Luis A / Beristain-Montiel, Erick / Restrepo, Gloria / Miranda, Javier / Alvarez-Ospina, Harry / Rojano, Roberto

    Environmental science and pollution research international

    2023  Volume 30, Issue 60, Page(s) 125915–125930

    Abstract: Air pollution in opencast coal mine areas is a critical issue, resulting in harmful severe effects on human health. Therefore, it is essential to understand the air pollution factors and to assess the risks to humans. This study evaluated the potential ... ...

    Abstract Air pollution in opencast coal mine areas is a critical issue, resulting in harmful severe effects on human health. Therefore, it is essential to understand the air pollution factors and to assess the risks to humans. This study evaluated the potential risks (carcinogen and non-carcinogen) of inhalation exposure to PM
    MeSH term(s) Humans ; Particulate Matter/analysis ; Air Pollutants/analysis ; Environmental Monitoring/methods ; Polycyclic Aromatic Hydrocarbons/analysis ; Latin America ; Lead/analysis ; Risk Assessment ; Neoplasms ; Carcinogens/analysis ; Metals, Heavy/analysis ; Coal/analysis ; China
    Chemical Substances Particulate Matter ; Air Pollutants ; Polycyclic Aromatic Hydrocarbons ; chromium hexavalent ion (18540-29-9) ; Lead (2P299V784P) ; Carcinogens ; Metals, Heavy ; Coal
    Language English
    Publishing date 2023-11-27
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1178791-0
    ISSN 1614-7499 ; 0944-1344
    ISSN (online) 1614-7499
    ISSN 0944-1344
    DOI 10.1007/s11356-023-30787-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Inter-annual variability of ice nucleating particles in Mexico city

    Cabrera-Segoviano, Diego / Pereira, Diana L. / Rodriguez, Camila / Raga, Graciela B. / Miranda, Javier / Alvarez-Ospina, Harry / Ladino, Luis A.

    Atmospheric environment. 2022 Mar. 15, v. 273

    2022  

    Abstract: The continuous and sustained population shift from rural to urban areas is driving most of the fast-growing megacities on a global scale. Considerable pollution, gases and particulate matter, is emitted yearly into the atmosphere of megacities, with ... ...

    Abstract The continuous and sustained population shift from rural to urban areas is driving most of the fast-growing megacities on a global scale. Considerable pollution, gases and particulate matter, is emitted yearly into the atmosphere of megacities, with unclear impacts on the local and regional hydrological cycle. The present work evaluated the inter-annual variability of super-micron (1.0–10 μm) ice nucleating particles (INP), via immersion freezing, sampled during the dry-warm season in Mexico City on two consecutive years using the UNAM-MicroOrifice Uniform Deposit Impactor-Droplet Freezing Technique (UNAM-MOUDI-DFT). The aerosol particles emitted in Mexico City were found to act as INP via the immersion freezing mode at temperatures below −20 °C with INP concentrations ranging between 0.74 L⁻¹ (−20 °C) and 20.42 L⁻¹ (−30 °C). Although the INP concentration varied between the dry-warm seasons, the average concentrations between 2018 and 2019 were rather similar, with significant differences only observed at −20 °C. The large increase (>200%) in fine particulate matter -PM₂.₅- observed during the 2019 severe air pollution episode caused by biomass burning (BB) emissions, did not impact the super-micron INP concentrations between −20 °C and −30 °C. However, INPs at temperatures above −15 °C were found to increase during the severe pollution episode. Given that such warm ice nucleation temperatures can be linked with the presence of biological particles, the present observations suggest that the BB plumes transported into Mexico City were most likely advecting co-emitted biological particles.
    Keywords aerosols ; air pollution ; biomass ; environment ; hydrologic cycle ; ice ; ice nucleation ; particulates ; Mexico
    Language English
    Dates of publication 2022-0315
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 216368-8
    ISSN 0004-6981 ; 1352-2310
    ISSN 0004-6981 ; 1352-2310
    DOI 10.1016/j.atmosenv.2022.118964
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: Characterization of aerosol particles during a high pollution episode over Mexico City.

    Carabali, Giovanni / Villanueva-Macias, José / Ladino, Luis A / Álvarez-Ospina, Harry / Raga, Graciela B / Andraca-Ayala, Gema / Miranda, Javier / Grutter, Michel / Silva, Ma Montserrat / Riveros-Rosas, David

    Scientific reports

    2021  Volume 11, Issue 1, Page(s) 22533

    Abstract: More than 7 thousand wildfires were recorded over Mexico in 2019, affecting almost 640 thousand hectares. Most of these fires occurred during the spring season generating dense smoke plumes, impacting urban areas in the central part of the Mexican ... ...

    Abstract More than 7 thousand wildfires were recorded over Mexico in 2019, affecting almost 640 thousand hectares. Most of these fires occurred during the spring season generating dense smoke plumes, impacting urban areas in the central part of the Mexican plateau. From May 10 to 17, 2019, biomass burning (BB) plumes affected Mexico City (MC) and diffused across the basin, producing PM
    Language English
    Publishing date 2021-11-18
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-021-01873-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Characterization of ice nucleating particles in rainwater, cloud water, and aerosol samples at two different tropical latitudes

    Pereira, Diana L / Silva, Ma. Montserrat / García, Rocío / Raga, Graciela B / Alvarez-Ospina, Harry / Carabali, Giovanni / Rosas, Irma / Martinez, Leticia / Salinas, Eva / Hidalgo-Bonilla, Sandra / Ladino, Luis A

    Atmospheric research. 2021 Mar., v. 250

    2021  

    Abstract: Ice nucleating particles (INPs) induce ice crystal formation and therefore, they are able to influence precipitation development. INP sources remain highly uncertain, with most of the observational studies performed in mid- and high-latitudes, bypassing ... ...

    Abstract Ice nucleating particles (INPs) induce ice crystal formation and therefore, they are able to influence precipitation development. INP sources remain highly uncertain, with most of the observational studies performed in mid- and high-latitudes, bypassing the Tropics. In the present study, rainwater, cloud water, and aerosol samples were collected during the rainy seasons in 2018 and 2019 in two major tropical capital cities: Quito and Mexico City, and at the high-altitude rural site Altzomoni (Mexico). The ice nucleating abilities of the rainwater samples from the urban sites (INP concentrations varying between 1.1 × 10² and 10⁵ L⁻¹ water at −9 °C and −24 °C) were not influenced by the pollution levels, consistent with the literature for other cities (e.g., Beijing and New Delhi), suggesting similarities in the behavior of INPs in densely populated and polluted cities. On the other hand, although the INP concentrations of the rural site samples were similar to those found in Quito and Mexico City (i.e., 7.1 × 10¹ and 1.1 × 10⁵), their onset freezing temperatures (T₀) were found to be higher (−7.5 °C as the highest). In terms of T₅₀ (the temperature at which 50% of the droplets freeze), the rainwater and the cloud water samples were found to be more efficient than the aerosol samples. The ice nucleating abilities of the rural site samples were reduced when applying the heating test, resulting in lower T₀ values, by more than 5 °C. Moreover, the presence of bacteria and fungal propagules on the rainwater and cloud water samples was also confirmed. Therefore, the high ice nucleating abilities observed on the samples from the rural site are likely related to biological material. Although K, Ca, S, Zn, and NO₃⁻ were found to be enriched in the cloud water samples in comparison to the aerosol particles, only Cu, Mn, and Zn were found to moderately correlate with the INP concentrations at −15 °C and −17 °C out of all the elements detected. Finally, the rainwater samples collected at those tropical sites were found to contain INPs concentrations lower than those found in other mid- and high-latitude sites. The information herein will improve the knowledge of INPs' contained in precipitation, their influence in tropical latitudes, and the development of new parameterizations.
    Keywords aerosols ; altitude ; capital ; fungi ; ice ; latitude ; pollution ; rain ; research ; temperature ; China ; India ; Mexico
    Language English
    Dates of publication 2021-03
    Publishing place Elsevier B.V.
    Document type Article
    Note NAL-AP-2-clean
    ISSN 0169-8095
    DOI 10.1016/j.atmosres.2020.105356
    Database NAL-Catalogue (AGRICOLA)

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  5. Article: Optimum quantification temperature for total, organic, and elemental carbon using thermal-coulombimetric analysis

    Alvarez-Ospina, Harry / María I. Saavedra / Oscar Peralta / Telma Castro

    Atmospheric environment. 2016 Nov., v. 145

    2016  

    Abstract: The quantification of total (TC), organic (OC), elemental carbon (EC), and OC/TC, EC/TC ratios is useful to determine the original sources of carbonaceous particles, so the importance of using appropriate standards is often crucial in atmospheric ... ...

    Abstract The quantification of total (TC), organic (OC), elemental carbon (EC), and OC/TC, EC/TC ratios is useful to determine the original sources of carbonaceous particles, so the importance of using appropriate standards is often crucial in atmospheric sciences, and the National Institute of Standards and Technology (NIST) offers good analytes. The Standard Reference Material (SRM) Urban Particulate Matter has a similar matrix as in the airborne aerosols of urban atmospheres and a well-known composition. The optimum quantification temperature analysis for carbon content of SRM 1648a and 1649b using a coulometric method (CM5300 and CM5014) is 500 °C for OC and 700 °C for TC. We also evaluated the repeatability and reproducibility provided by the instrument. It should be pointed out that SRM 1649b has no OC or TC quantification in its Certificate of Analysis, so this study may serve as a basis for future analysis of carbon content of atmospheric aerosols.
    Keywords aerosols ; atmospheric chemistry ; carbon ; particulates ; temperature
    Language English
    Dates of publication 2016-11
    Size p. 74-80.
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 216368-8
    ISSN 0004-6981 ; 1352-2310
    ISSN 0004-6981 ; 1352-2310
    DOI 10.1016/j.atmosenv.2016.08.080
    Database NAL-Catalogue (AGRICOLA)

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  6. Book ; Online: Mexican agricultural soil dust as a source of ice nucleating particles

    Pereira, Diana L. / Gavilán, Irma / Letechipía, Consuelo / Raga, Graciela B. / Puig, Teresa Pi / Mugica-Álvarez, Violeta / Alvarez-Ospina, Harry / Rosas, Irma / Martinez, Leticia / Salinas, Eva / Quintana, Erika T. / Rosas, Daniel / Ladino, Luis A.

    eISSN: 1680-7324

    2022  

    Abstract: Agricultural soil erosion, both mechanical and eolic, may impact cloud processes, as some aerosol particles are able to facilitate ice crystal formation. Given the large agricultural sector in Mexico, this study investigates the ice nucleating abilities ... ...

    Abstract Agricultural soil erosion, both mechanical and eolic, may impact cloud processes, as some aerosol particles are able to facilitate ice crystal formation. Given the large agricultural sector in Mexico, this study investigates the ice nucleating abilities of agricultural dust collected at different sites and generated in the laboratory. The immersion freezing mechanism of ice nucleation was simulated in the laboratory via the Universidad Nacional Autónoma de México (UNAM) microorifice uniform deposit impactor (MOUDI) droplet freezing technique (DFT), i.e., UNAM-MOUDI-DFT. The results show that agricultural dust from the Mexican territory promote ice formation in the temperature range from −11.8 to −34.5 ∘ C, with ice nucleating particle (INP) concentrations between 0.11 and 41.8 L −1 . Furthermore, aerosol samples generated in the laboratory are more efficient than those collected in the field, with T 50 values (i.e., the temperature at which 50 % of the droplets freeze) higher by more than 2.9 ∘ C. Mineralogical analysis indicated a high concentration of feldspars, i.e., K-feldspar and plagioclase ( >40 %), in most of the aerosol and soil samples, with K-feldspar significantly correlated with the T 50 of particles with aerodynamic diameters between 1.8 and 3.2 µm . Similarly, the organic carbon (OC) was correlated with the ice nucleation efficiency of aerosol samples from 3.2 to 5.6 and from 1.0 to 1.8 µm . Finally, a decrease in INP efficiency after heating the samples at 300 ∘ C for 2 h indicates that the organic matter from agricultural soils plays a predominant role in the ice nucleating abilities of this type of aerosol sample.
    Subject code 333
    Language English
    Publishing date 2022-05-19
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Book ; Online: African dust particles over the western Caribbean – Part I

    Ramírez-Romero, Carolina / Jaramillo, Alejandro / Córdoba, María F. / Raga, Graciela B. / Miranda, Javier / Alvarez-Ospina, Harry / Rosas, Daniel / Amador, Talib / Kim, Jong Sung / Yakobi-Hancock, Jacqueline / Baumgardner, Darrel / Ladino, Luis A.

    eISSN: 1680-7324

    Impact on air quality over the Yucatán Peninsula

    2021  

    Abstract: On a global scale, African dust is known to be one of the major sources of mineral dust particles, as these particles can be efficiently transported to different parts of the planet. Several studies have suggested that the Yucatán Peninsula could be ... ...

    Abstract On a global scale, African dust is known to be one of the major sources of mineral dust particles, as these particles can be efficiently transported to different parts of the planet. Several studies have suggested that the Yucatán Peninsula could be influenced by such particles, especially in July, associated with the strengthening of the Caribbean low-level jet. Although these particles have the potential to significantly impact the local air quality, as shown elsewhere (especially with respect to particulate matter, PM), the arrival and impact of African dust in Mexican territory has not been quantitatively reported to date. Two short-term field campaigns were conducted to confirm the arrival of African dust on the Yucatán Peninsula in July 2017 and July 2018 at the Mérida atmospheric observatory (20.98 ∘ N, 89.64 ∘ W). Aerosol particles were monitored at ground level using different online and off-line sensors. Several PM 2.5 and PM 10 peaks were observed during both sampling periods, with a relative increase in the PM levels ranging between 200 % and 500 % with respect to the normal background conditions. Given that these peaks were found to be highly correlated with supermicron particles and chemical elements typically found in mineral dust particles, such as Al, Fe, Si, and K, they are linked with African dust. This conclusion is supported by combining back trajectories with vertical profiles from radiosondes, reanalysis, and satellite images to show that the origin of the air masses arriving at Mérida was the Saharan Air Layer (SAL). The good agreement found between the measured PM 10 concentrations and the estimated dust mixing ratio content from MERRA-2 (Version 2 of the Modern-Era Retrospective analysis for Research and Applications) corroborates the conclusion that the degradation of the local (and likely regional) air quality in Mérida is a result of the arrival of African dust.
    Subject code 333
    Language English
    Publishing date 2021-01-12
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: HPLC determination of the major active flavonoids and GC-MS analysis of volatile components of Dysphania graveolens (Amaranthaceae).

    Alvarez-Ospina, Harry / Rivero Cruz, Isabel / Duarte, Georgina / Bye, Robert / Mata, Rachel

    Phytochemical analysis : PCA

    2013  Volume 24, Issue 3, Page(s) 248–254

    Abstract: Introduction: Dysphania graveolens is used mainly in Mexican traditional medicine against gastrointestinal ailments. Previous investigations revealed that its flavonoids are important active principles; however, there is not a reliable and accurate ... ...

    Abstract Introduction: Dysphania graveolens is used mainly in Mexican traditional medicine against gastrointestinal ailments. Previous investigations revealed that its flavonoids are important active principles; however, there is not a reliable and accurate analytical method for determining these compounds in the crude drug or preparations of the plant. In addition, its volatile chemical composition remains unknown.
    Objective: The main goals were to develop a validated HPLC method for quantifying the active flavonoids (pinostrobin (1), pinocembrin (2) and chrysin (3)) of D. graveolens and to establish its volatile composition.
    Methodology: Separation was carried out on a Licrospher100 RP18 column with a linear gradient acetonitrile 0.1% formic acid and aqueous 0.1% formic acid. Accuracy was determined by spiking the crude drug with the standards, the recoveries were between 99% and 101%. A systematic description of the volatile components of D. graveolens was assessed via GC-MS using headspace solid-phase microextraction (HS-SPME) and hydrodistillation extraction methods.
    Results: The developed HPLC method represented a powerful technique for the quality control of D. graveolens allowing the quantification of the three active flavonoids. For each compound a linear response was evaluated within the range of 0.5-2.0 mg/mL for pinostrobin (1), 0.25-1.25 mg/mL for pinocembrin (2) and 0.05-0.5 mg/mL for chrysin (3). According to SPME the major components in D. graveolens were p-cymene (84.85%) and eucalyptol (11.26%). On the other hand, the essential oil had eucalyptol (42.89%) and p-cymene (16.51%) and did not contain ascaridol. Thus the most relevant volatile components in the species were monoterpenoids.
    MeSH term(s) Amaranthaceae/chemistry ; Chromatography, High Pressure Liquid/methods ; Flavanones/analysis ; Flavonoids/analysis ; Flavonoids/chemistry ; Gas Chromatography-Mass Spectrometry/methods ; Oils, Volatile/chemistry ; Plant Components, Aerial/chemistry ; Plants, Medicinal/chemistry ; Reproducibility of Results ; Solid Phase Microextraction/methods
    Chemical Substances Flavanones ; Flavonoids ; Oils, Volatile ; chrysin (3CN01F5ZJ5) ; pinocembrin (8T7C8CH791) ; pinostrobin (SZD9LZS694)
    Language English
    Publishing date 2013-05
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1073576-8
    ISSN 1099-1565 ; 0958-0344
    ISSN (online) 1099-1565
    ISSN 0958-0344
    DOI 10.1002/pca.2405
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Book ; Online: African Dust Particles over the Western Caribbean Part I

    Ramirez-Romero, Carolina / Jaramillo, Alejandro / Cordoba, Maria F. / Raga, Graciela B. / Miranda, Javier / Alvarez-Ospina, Harry / Rosas, Daniel / Amador, Talib / Kim, Jong Sung / Yakobi-Hancock, Jacqueline / Baumgardner, Darrel / Ladino, Luis A.

    eISSN: 1680-7324

    Impact on air quality over the Yucatan Peninsula

    2020  

    Abstract: On a global scale, African dust is known as one of the major sources of mineral dust particles as they can be efficiently transported to different parts of the planet. Several studies have suggested that the Yucatan Peninsula could be influenced by such ... ...

    Abstract On a global scale, African dust is known as one of the major sources of mineral dust particles as they can be efficiently transported to different parts of the planet. Several studies have suggested that the Yucatan Peninsula could be influenced by such particles, especially in July, associated with the strengthening of the Caribbean low level jet. Although these particles have the potential to impact the local air quality significantly, as shown elsewhere (especially particulate matter, PM), the arrival and the impact of African dust into Mexican territory has not been quantitatively reported to date. Two short-term field campaigns were conducted to confirm the arrival of African dust onto the Yucatan Peninsula in July 2017 and July 2018 at the city of Merida atmospheric observatory (20.98° N 89.64° W). Aerosol particles were monitored at the ground level by different on-line and off-line sensors. Several PM 2.5 and PM 10 peaks were observed during both sampling periods, with a relative increase in the PM levels ranging between 200 % and 500 % with respect to the normal background. Given that these peaks were found to highly correlate with super micron particles and chemical elements typically found in mineral dust particles, such as Al, Fe, Si, and K, they are linked with African dust. This conclusion is supported by combining back trajectories with vertical profiles from radiosondes, reanalysis, and satellite images to show that the origin of the air masses arriving at Merida was the Saharan Air Layer (SAL). The good agreement found between the measured PM>sub>10 concentrations and the estimated dust mixing ratio content from MERRA-2 (Version 2 of the Modern-Era Retrospective analysis for Research and Applications) corroborates the conclusion that the degradation of the local (and likely regional) air quality in Merida is a result of the arrival of African dust.
    Subject code 333
    Language English
    Publishing date 2020-06-16
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article: Atmospheric black carbon concentrations in Mexico

    Peralta, Oscar / Alvarez-Ospina, Harry / Barrera, Valter / Basaldud, Roberto / Castro, Telma / de la Cruz, Karen / de la Luz Espinosa, María / Gavilán, Arturo / Martínez-Arroyo, Amparo / Ortínez-Alvarez, Abraham / Páramo, Víctor H / Ruíz-Suárez, Luis G / Saavedra, Isabel / Santiago, Naxieli / Vazquez-Galvez, Felipe A

    Atmospheric research. 2019 Dec. 01, v. 230

    2019  

    Abstract: Atmospheric black carbon concentrations were measured at two urban sites (Mexico City and Monterrey), one suburban site (Juriquilla) and one high-altitude site (Altzomoni) in Mexico during 2015 and part of 2016. Black carbon concentrations were compared ... ...

    Abstract Atmospheric black carbon concentrations were measured at two urban sites (Mexico City and Monterrey), one suburban site (Juriquilla) and one high-altitude site (Altzomoni) in Mexico during 2015 and part of 2016. Black carbon concentrations were compared against other criteria gases finding a strong correlation with carbon monoxide at the urban sites. The carbon monoxide-black carbon correlation for the Mexico City site is 0.77. Urban sites had an average black carbon concentration of above 2.5 μg m−3, the suburban site 0.75 μg m−3, and the high-altitude site 0.27 μg m−3. Compared to other studies, the average levels are comparable, and the urban and suburban locations showed a trend towards increased atmospheric black carbon concentrations at year end. Other urban places (Guadalajara, Cuernavaca, and Iztapalapa) reported black carbon concentrations, but for less than a year. For the first time, a Latin-American country (Mexico) measured black carbon continuously at several sites for a year applying the same data quality assurance.
    Keywords altitude ; carbon ; carbon monoxide ; data quality ; gases ; quality control ; urban areas ; Mexico
    Language English
    Dates of publication 2019-1201
    Publishing place Elsevier B.V.
    Document type Article
    ISSN 0169-8095
    DOI 10.1016/j.atmosres.2019.104626
    Database NAL-Catalogue (AGRICOLA)

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