Mapping and Estimation of Nitrogen and Sulfur Atmospheric Deposition Fluxes in Central Region of the Mexican Bajio

The objective of this study was to assess the spatial and temporal distribution of nitrogen and sulfur deposition and its relationship with meteorological conditions in the metropolitan area of León in Guanajuato, México. N and S atmospheric deposition was collected using passive samplers (IER) in 10 sites in León City during three climatic seasons in 2018. Nitrate, ammonium, and sulfate concentrations and deposition fluxes of N and S were determined. From wind and air-mass trajectories analysis, mechanisms and possible sources contributing to N and S deposition in the study area were assessed. Atmospheric deposition fluxes were compared to critical load values reported for sensitive ecosystems in Europe. It was found that mean deposition flux for N (5.82 Kg N ha−1 year−1) was within the range of values reported for sensitive ecosystems in Nuevo México, Europe, and California. On the other hand, the mean deposition flux for S (13.77 S Kg ha−1 year−1) exceeded the critical load values proposed for Europe, suggesting that current S deposition could be a risk for ecosystems and water bodies in the region

Characterization and Sources of Aromatic Hydrocarbons (BTEX) in the Atmosphere of Two Urban Sites Located in Yucatan Peninsula in Mexico

Abstract:Benzene,toluene,ethylbenzene,p-xylene,O3,NOx,CO,PM2.5 andmeteorologicalparameters were measured in urban air of two sites in Merida, Yucatan, Mexico during 2016–2017. Samples were collected using 1.5 h time intervals at three different sampling periods before being analyzed by gas chromatographywithflameionizationdetection. ThehighestconcentrationsofBTEXoccurredduring midday and afternoon in spring and summer seasons. Mean concentrations of, BTEX for the Cholul and SEDUMA sites, respectively, were 40.91 µg/m3 and 32.86 µg/m3 for benzene; 6.87 µg/m3 and 3.29 µg/m3 for toluene; 13.87 µg/m3 and 8.29 µg/m3 for p-xylene; and 6.23 µg/m3 and 4.48 µg/m3 for ethylbenzene. The toluene/benzene and xylene/ethylbenzene concentration ratios indicated that BTEX levels at both sites were influenced by local and fresh emissions (vehicular traffic). Bivariate and multivariate analyses were performed in order to correlate BTEX concentrations with criteria air pollutants to infer their possible sources. Health risk assessment revealed that exposure to benzene exceeded the recommended value for the integrated lifetime cancer risk. These results suggest that Merida’s population is exposed to cancer risk, and changes in the existing environmental policies should therefore be applied to improve air quality. Keywords: volatile organic compounds; BTEX; tropospheric ozone; Merida; air pollutio

Mapping of the atmospheric deposition of sulfur and nitrogen during the dry season 2016 in the Metropolitan zone of Merida, Yucatan, Mexico

Abstract. Atmospheric deposition of sulfur and nitrogen was measured in the Metropolitan Area of Merida, Yucatan in Mexico during the dry season of 2016. Passive samplers type "throughfall" based on ion exchange resins were used to measure the hydrological flows in a total of 9 sampling sites distributed throughout the city. The ions retained in the resin were analyzed by turbidimetry and colorimetry to determine Ammonium, Nitrate and Sulfate. Deposition fluxes of S and N obtained were 6.25 and 5.19 Kg ha-1 yr-1. Both, sulfur and nitrogen atmospheric deposition fluxes were higher in urban sites, exceeding almost 2 times, the reference values proposed internationally for sensitive ecosystems. From the analysis of wind roses and air masses trajectories, it was possible to establish that during this climatic season, in addition to the local vehicular emissions, regional emissions generated upwind (from E-SE) contributed to atmospheric deposition of these ions. Finally, N and S deposition fluxes and their relationship with criteria pollutants were assessed, and maps for atmospheric deposition fluxes of Ammonium, Sulfate and Nitrate were generated using geo-statistical tools in order to identify critical deposition zones in this Metropolitan zone

Atmospheric N and S Deposition Fluxes in the Metropolitan Area of Monterrey, Mexico and Its Relation with Criteria Air Pollutants and Meteorological Conditions

The objective of this study was to assess the spatial and temporal variability of N and S atmospheric deposition and its relation with criteria air pollutants (CAPs) and meteorological conditions (MCs) in the metropolitan area of Monterrey (MAM). Atmospheric deposition was collected in 10 sampling sites during 3 climatic periods by using passive samplers based on ionic exchange resins (IERs); simultaneously, CAP and MC were monitored. Ions were extracted from IER to determine nitrate, ammonium, and sulfate levels, and deposition fluxes were estimated. On the other hand, from CAP and MC, wind and concentration roses were built to identify the exceedances of the current regulations, and relationships between CAP and meteorological conditions. It was found that only S deposition fluxes exceeded critical load values proposed in Europe, suggesting that S deposition could be a serious threat in MAM. It was found that CO in Juárez sampling site and O3 and PM10 in all sampling sites showed exceedances of the current regulatory limits, showing seasonal and spatial patterns similar to N and S deposition fluxes. Deposition fluxes were mapped to identify critical zones or periods in which these fluxes could be higher as a result of the prevailing meteorological conditions

EVALUACIÓN GEOLÓGICA Y PROSPECTIVIDAD SECTOR SINÚ - URABÁ

RESUMEN   El área especial Sinú - Urabá, comprende cuatro provincias tectónicas identificadas de este a oeste como la Cuenca del Valle Inferior del Magdalena, Cinturón Plegado de San Jacinto, Cinturón Plegado del Sinú y Cuenca de Urabá con 46.300 Km2. El Valle inferior del Magdalena es una cuenca con tectónica distensiva producto de transtensión, los plays identificados corresponden con pliegues compresivos, truncamientos del reservorio por fallas, sobrelape del reservorio contra el basamento y altos de basamento. El Cinturón Plegado de San Jacinto es caracterizado por tectónica transpresiva generando fallas inversas de escama gruesa, los plays son pliegues compresivos, truncamientos de los reservorios por fallas y rellenos de canales en valles de incisión; El Cinturón Plegado del Sinú es catalogado por procesos estructurales y tectónicos no muy claros deformado por intenso diapirismo de lodo, los plays identificados corresponden con pliegues asociados a etapas tempranas de formación de diapiros de lodo que no rompen completamente la secuencia, truncamientos de los reservorios contra los diapiros y por discordancias sindeposicionales y la Provincia de Urabá es sujeta a transpresión sinestral con desarrollo de fallas inversas de ángulo alto, los plays identificados corresponden con acuñamientos de sedimentos y crecimientos arrecifales y pliegues formados por fallas inversas.   Palabras clave: Geología del Petróleo, Sistema Petrolífero, Prospectividad, Plays, Geoquímica, Geología Estructural.   GEOLOGICAL EVALUATION AND PROSPECTIVITY SINÚ - URABÁ SECTOR   ABSTRACT   The Sinú - Urabá special area consists of four tectonic provinces. They are identified from East to West as Lower Magdalena Valley Basin (LMV), San Jacinto Fold Belt (SJFB), Sinú Fold Belt (SFB) and Urabá Basin and 46.300 Km2. The Lower Magdalena Valley is a basin with distensive tectonics which was a product of transtension; the identified plays correspond to compressional folds (over the west border of the basin), reservoir truncations due to faults, overstepping of the reservoir against the basement and basement highs. The San Jacinto Fold Belt shows transpressive tectonics that generates rough flake reverse faults with dextral strike-slip, the plays correspond to compressional folds, reservoir truncations due to faults and locally-filled truncations of channels in incision valleys. The Sinú Folded Belt is formed by not very clear structural and tectonic processes; and it is deformed by mud intense diapirism; the plays correspond to folds associated to early formation stages of mud diapirs, which do no break the sequence completely, reservoir truncations against the diapirs and due to sinde-positional discordances. The Urabá Province is subject to sinistral transpressure with development of high angle reverse faults, the identified plays correspond to facies wedging, reef growth and folds formed by reverse faults.   Key words: Petroleum Geology, Petroleum System, Prospectivity, Plays, Geochemistry, Structural Geology. &nbsp

EVALUACIÓN GEOLÓGICA Y PROSPECTIVIDAD SECTOR SINÚ - URABÁ

RESUMEN   El área especial Sinú - Urabá, comprende cuatro provincias tectónicas identificadas de este a oeste como la Cuenca del Valle Inferior del Magdalena, Cinturón Plegado de San Jacinto, Cinturón Plegado del Sinú y Cuenca de Urabá con 46.300 Km2. El Valle inferior del Magdalena es una cuenca con tectónica distensiva producto de transtensión, los plays identificados corresponden con pliegues compresivos, truncamientos del reservorio por fallas, sobrelape del reservorio contra el basamento y altos de basamento. El Cinturón Plegado de San Jacinto es caracterizado por tectónica transpresiva generando fallas inversas de escama gruesa, los plays son pliegues compresivos, truncamientos de los reservorios por fallas y rellenos de canales en valles de incisión; El Cinturón Plegado del Sinú es catalogado por procesos estructurales y tectónicos no muy claros deformado por intenso diapirismo de lodo, los plays identificados corresponden con pliegues asociados a etapas tempranas de formación de diapiros de lodo que no rompen completamente la secuencia, truncamientos de los reservorios contra los diapiros y por discordancias sindeposicionales y la Provincia de Urabá es sujeta a transpresión sinestral con desarrollo de fallas inversas de ángulo alto, los plays identificados corresponden con acuñamientos de sedimentos y crecimientos arrecifales y pliegues formados por fallas inversas.   Palabras clave: Geología del Petróleo, Sistema Petrolífero, Prospectividad, Plays, Geoquímica, Geología Estructural.   GEOLOGICAL EVALUATION AND PROSPECTIVITY SINÚ - URABÁ SECTOR   ABSTRACT   The Sinú - Urabá special area consists of four tectonic provinces. They are identified from East to West as Lower Magdalena Valley Basin (LMV), San Jacinto Fold Belt (SJFB), Sinú Fold Belt (SFB) and Urabá Basin and 46.300 Km2. The Lower Magdalena Valley is a basin with distensive tectonics which was a product of transtension; the identified plays correspond to compressional folds (over the west border of the basin), reservoir truncations due to faults, overstepping of the reservoir against the basement and basement highs. The San Jacinto Fold Belt shows transpressive tectonics that generates rough flake reverse faults with dextral strike-slip, the plays correspond to compressional folds, reservoir truncations due to faults and locally-filled truncations of channels in incision valleys. The Sinú Folded Belt is formed by not very clear structural and tectonic processes; and it is deformed by mud intense diapirism; the plays correspond to folds associated to early formation stages of mud diapirs, which do no break the sequence completely, reservoir truncations against the diapirs and due to sinde-positional discordances. The Urabá Province is subject to sinistral transpressure with development of high angle reverse faults, the identified plays correspond to facies wedging, reef growth and folds formed by reverse faults.   Key words: Petroleum Geology, Petroleum System, Prospectivity, Plays, Geochemistry, Structural Geology. &nbsp

Short-term Effects of Air Pollution on Health in the Metropolitan Area of Guadalajara using a Time-series Approach

ABSTRACT This work have like purpose quantitative estimates of the short-term effects of air pollution on the health of residents of five municipalities of the Metropolitan Area of Guadalajara, Mexico from 2012 to 2015 using time-series approach. Air Quality was assessed for CO, NO2, SO2, O3 and PM10. Tlaquepaque had the highest mean concentrations for CO (0.88 ppm), NO2 (24.55 ppb), SO2 (0.0036 ppm) and PM10 (53.81 µg m–3), whereas, Zapopan registered the highest mean value for O3 (25.06 ppb). Only PM10 and Ozone exceeded the maximum permissible values established in the Mexican official standards. SO2 presented the highest RRI values in MAG, especially for Zapopan and Tonala, for the majority of the population: 0–59 years and > 60 years. Regarding to CO, excepting Guadalajara and Tlaquepaque, associations were not significant in the most of studied municipalities. The increase of risk as percentage for NO2 was 1.77% for 0–59 years in Guadalajara and Tlaquepaque, 1.87% by respiratory causes in Tlaquepaque, 1.73% > 60 years in Tonala, and 1.25% for 0–59 years in Zapopan. The association between daily mortality and increased O3 levels were significant, however, values were low for all studied municipalities. Finally, regarding to PM10, only Zapopan and Tonala showed statistical significance. This study cannot predict if reductions in criteria pollutants levels would have an important effect on a reduction in daily mortality, however, considering the large size of population exposed, even when observed associations were small but significant, RRI values found are of public concern. Keywords: Relative risk index; Mortality; Megacities; Criteria air pollutants; Mexico

Bioactives Overproduction through Operational Strategies in the Ichthyotoxic Microalga Heterosigma akashiwo Culture

The red tide-forming microalga Heterosigma akashiwo has been associated with massive events of fish deaths, both wild and cultured. Culture conditions are responsible for the synthesis or accumulation of some metabolites with different interesting bioactivities. H. akashiwo LC269919 strain was grown in a 10 L bubble column photobioreactor artificially illuminated with multi-coloured LED lights. Growth and production of exopolysaccharides, polyunsaturated fatty acids (PUFAs), and carotenoids were evaluated under different culture modes (batch, fed-batch, semicontinuous, and continuous) at two irradiance levels (300 and 700 µE·s−1·m−2). Continuous mode at the dilution rate of 0.2·day−1 and 700 µE·s−1·m−2 provided the highest production of biomass, PUFAs (132.6 and 2.3 mg·L−1·day−1), and maximum fucoxanthin productivity (0.16 mg·L−1·day−1). The fed-batch mode accumulated exopolysaccharides in a concentration (1.02 g·L−1) 10-fold over the batch mode. An extraction process based on a sequential gradient partition with water and four water-immiscible organic solvents allowed the isolation of bioactive fucoxanthin from methanolic extracts of H. akashiwo. Metabolites present in H. akashiwo, fucoxanthin and polar lipids (i.e., eicosapentaenoic acid (EPA)), or probably such as phytosterol (β-Sitosterol) from other microalgae, were responsible for the antitumor activity obtained.This research was funded by the General Secretariat of Universities, Research and Technology of the Andalusian Government (grant: P18-RT-2477) and the State Research Agency (grants PID2019-109476RB-C22) of the Spanish Ministry of Science, Innovation and Universities