Analysis of s-triazine-degrading microbial communities in soils using most-probable-number enumeration and tetrazolium-salt detection

A simple and sensitive method for the detection and enumeration of microbial s-triazine-degrading microorganisms in soil was designed. The procedure is based on the ability of some microbes to use s-triazines, such as simazine, atrazine, and cyanuric acid, as sole nitrogen source. It employs the respiration indicator 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) to detect metabolic activity and the most-probable-number (MPN) enumeration in microtiter plates. The method was used to identify simazine- and cyanuric acid-degrading activities in agricultural soils treated with the herbicide simazine. The MPN-TTC method showed that the number of simazine- and cyanuric acid-degrading microorganisms increased four weeks after the herbicide simazine had been applied. [Int Microbiol 2007; 10(3):209-215

Detection of Snow Pollution in the Chilean Andes Using DESIS Hyperspectral Data

This conference paper explored the possibility of using hyperspectral DESIS images to study snow pollution (particularly black carbon) at two test sites in the Chilean Andes

Evaluación de patrones y fuentes de metales traza antropogénicos en la atmósfera de Los Andes Centrales mediante la combinación de mediciones in situ con un modelo de dispersión atmosférico

Este trabajo presenta la evaluación de la composición de nieve fresca de Los Andes Centrales como indicador ambiental de la influencia de las actividades antrópicas y la calidad del aire en el área. En tal sentido, en los años 2014-2015-2016, se realizaron campañas estacionales de muestreo de nieve para la determinación de metales traza representativos antropogénicos (Cu, Pb y Zn) en dos puntos característicos del área de estudio. Los resultados mostraron valores elevados en comparación con estudios similares realizados en otros sitios montañosos nevados del mundo, lo que sugiere una gran relevancia del alto tráfico de vehículos en la zona; las actividades mineras y la cercanía de centros urbanos. Se realizó además una simulación de la dispersión atmosférica y deposición utilizando el modelo CALPUFF, particularmente apropiado para estimar concentraciones en la atmósfera en entornos complejos.Fil: Ruggeri, María Florencia. Universidad Tecnica Federico Santa Maria.; Chile. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Castesana, Paula Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; ArgentinaFil: Bolaño, Tomás. Universidad Tecnológica Nacional. Facultad Regional de Mendoza; ArgentinaFil: Puliafito, Salvador Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: Cereceda Balic, Francisco. Universidad Tecnica Federico Santa Maria.; ChileReunión 2019 de la Sociedad Chilena de la CriósferaLa SerenaChileCentro de Estudios Avanzados en Zonas Árida

Spread of COVID-19, Meteorological Conditions and Air Quality in the City of Buenos Aires, Argentina: Two Facets Observed during Its Pandemic Lockdown

This work studied the spread of COVID-19, the meteorological conditions and the air quality in a megacity from two viewpoints: (1) the correlation between meteorological and air quality (PM10 and NO2) variables with infections and deaths due COVID-19, and (2) the improvement in air quality. Both analyses were performed for the pandemic lockdown due to COVID-19 in the City of Buenos Aires (CABA), the capital and the largest city in Argentina. Daily data from temperature, rainfall, average relative humidity, wind speed, PM10, NO2, new cases and deaths due COVID-19 were analyzed. Our findings showed a significant correlation of meteorological and air quality variables with COVID-19 cases. The highest temperature correlation occurred before the confirmation day of new cases. PM10 presented the highest correlation within 13 to 15 days lag, while NO2 within 3 to 6 days lag. Also, reductions in PM10 and NO2 were observed. This study shows that exposure to air pollution was significantly correlated with an increased risk of becoming infected and dying due to COVID-19. Thus, these results show that the NO2 and PM10 levels in CABA can serve as one of the indicators to assess vulnerability to COVID-19. In addition, decision-makers can use this information to adopt strategies to restrict human mobility during the COVID-19 pandemic and future outbreaks of similar diseases in CABA.Fil: Bolaño Ortiz, Tomas Rafael. Universidad Tecnológica Nacional. Facultad Regional de Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pascual Flores, Romina María. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Puliafito, Salvador Enrique. Universidad Tecnológica Nacional. Facultad Regional de Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Camargo Caicedo, Yiniva. Universidad del Magdalena; ColombiaFil: Berná Peña, Lucas Luciano. Universidad Tecnológica Nacional. Facultad Regional de Mendoza; Argentina. Ministerio de Ciencia. Tecnología e Innovación Productiva. Agencia Nacional de Promoción Científica y Tecnológica; ArgentinaFil: Ruggeri, María Florencia. Universidad Tecnica Federico Santa Maria; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lopez Noreña, Ana Isabel. Universidad Tecnológica Nacional. Facultad Regional de Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tames, María Florencia. Universidad Tecnológica Nacional. Facultad Regional de Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cereceda Balic, Francisco. Universidad Tecnica Federico Santa Maria; Chil

Understanding the role of anthropogenic emissions in glaciers retreat in the central Andes of Chile

Glaciers in Chilean Central Andes have significatively retreated, at least, in the last 60 years. From 2004 to 2014, the largest retreat in the area (−0.15 km2 yr−1) was observed at Olivares Alpha Glacier (OAG). Previous glacier fluctuation studies proposed that two open-pit mines distant 7 km from the glacier could be the cause of its enhanced retreat. However, this had not been yet tested due to the lack of measured data. Here, we investigated the impact that major air pollutants emitted by local mining activities could have on the differences observed in OAG glacial retreat compared with a glacier of similar size and altitude with no nearby anthropogenic sources: Bello Glacier (BG), which has a reported lower retreat (−0.02 km2 yr−1). Results revealed a link between anthropogenic air pollutants and glacial retreat rates, meaning that glacial retreat is decoupled from climatic and glaciological factors. Considering that both glaciers are located in the same climatic setting, the anthropogenic air pollutants deposited onto the OAG surface appear to be forcing positive feedback in which the pollutants deposition best explain the differences in the glacier retreat. With the results of this study, it has been calculated that the impact of mining in OAG could be responsible for 82% of its total retreat since between 2004 and 2014, and only the remaining 18% would correspond to the impact of climate change.Fil: Cereceda Balic, Francisco. Universidad Técnica Federico Santa María; ChileFil: Ruggeri, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Técnica Federico Santa María; ChileFil: Vidal, Víctor. Universidad Técnica Federico Santa María; ChileFil: Ruiz, Lucas Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Fu, Joshua S.. University of Tennessee; Estados Unido

Impacts of Soot, Ash, Sand, and Haze on Snow Albedo in Sierra Nevada, Spain

Snow covers are greatly affected by particles deposited on their surface. In this work, an experimental campaign was carried out in the Sierra Nevada (Granada, Spain). The optical effect of different contaminating particles on the snow covers was measured using a field spectroradiometric system composed of three upwelling spectroradiometers and three downwelling ones. Sand collected from a Mediterranean beach (Spain), ash collected from the La Palma volcano eruption, haze collected from an event that occurred in Spain, and soot collected from a diesel vehicle were employed for contaminating the snow. Soot, ash, and sand were analysed with X-ray diffraction to obtain their mineralogical composition or their structural characteristics, whereas haze's mineralogical composition was obtained from the literature. From this information, the refractive index of each material was weigh-averaged, considering the refractive indices of their components. After measurements, snow samples were filtered and weighted to evaluate the particle concentrations in the snow. Previous contamination with soot was observed due to the existence of a nearby road. Snow albedo was calculated with the OptiPar model. The experimental and modelled results show that contaminating with sand decreases the snow albedo in the visible range whereas it increases the albedo in the infrared range. However, the rest of the materials lead to a decrease in the albedo in the whole spectrum, although with different intensities depending on the wavelength range

Trace Element Levels in Native Plant Species around the Industrial Site of Puchuncaví-Ventanas (Central Chile): Evaluation of the Phytoremediation Potential

The present work investigates the uptake of selected trace elements (Cu, Sb, As, Pb, Cd, Zn, Cr, Mn, Ni, V, and Co) from soil and their accumulation in the biomass samples (leaves and flowers) of three selected native plants (namely Oenothera picensis, OP; Sphaeralcea velutina, SV; and Argemone subfusiformis, AS) around an industrial area (Puchuncaví-Ventanas) located in the Puchuncaví valley, in the central region of Chile. Primary emission sources in the area come from a copper refinery, coal-fired power plants, and a set of 14 other different industrial facilities. Trace element measurements in the native plants of this area and the ability to transfer of these pollutants from soil to plants (transfer factor) have been assessed in order to identify the potential use of these plant species for phytoremediation. Preliminary results showed a high concentration of trace elements in the OP, SV, and AS samples. The concentration of these elements in the plants was found to be inversely correlated to the distance of the primary emission sources. Moreover, the high concentrations of trace elements such as Cu, As, Cr and V, upon the toxic limits in the native plant species, suggest the need for continuous monitoring of the region. The OP species was identified as the plant with the highest capacity for trace elements accumulation, which also showed higher accumulation potential in whole aerial parts than in leaves. Transfer factor values suggested that these native plants had phytoremediation potential for the elements Cu, Pb, As, Ni, and Cr. This study provides preliminary baseline information on the trace element compositions of important native plants and soil in the Puchuncaví-Ventanas area for phytoremediation purposes