Stable isotopes and geochemical indicators in marine sediments as proxies for anthropogenic impact: A baseline for coastal environments of central Chile (33°S).

Stable isotopes and geochemical proxies (TOC/TN and Chla/TOC) in sediments can be used to distinguish organic matter sources (anthropogenic, terrestrial, or marine). This study aims to characterize organic matter (OM) in superficial sediments from three sectors of central Chile (33°S) that are highly influenced by urban and industrial development. Our results show that a substantial fraction of these OM in Quintero Bay is anthropogenic, from industrial and domestic wastewater sources. In contrast, a mixture of terrestrial and anthropogenic OM dominates the isotopic signal of surface sediments from Concón, derived from non-point industrial and agriculture sources associated with the Aconcagua River basin, while Ritoque exhibited a mixture of different OM sources. However, deposition of allochthonous OM in our study area depends on coastal topography, which influences the local currents and well-ventilated waters, promoting the dispersion and assimilation of OM and thus providing an environment with a high capacity for natural remediation.

Non-point source pollution of glyphosate and AMPA in a rural basin from the southeast Pampas, Argentina.

We measured the occurrence and seasonal variations of glyphosate and its metabolite, aminomethylphosphonic acid (AMPA), in different environmental compartments within the limits of an agricultural basin. This topic is of high relevance since glyphosate is the most applied pesticide in agricultural systems worldwide. We were able to quantify the seasonal variations of glyphosate that result mainly from endo-drift inputs, that is, from direct spraying either onto genetically modified (GM) crops (i.e., soybean and maize) or onto weeds in no-till practices. We found that both glyphosate and AMPA accumulate in soil, but the metabolite accumulates to a greater extent due to its higher persistence. Knowing that glyphosate and AMPA were present in soils (> 93% of detection for both compounds), we aimed to study the dispersion to other environmental compartments (surface water, stream sediments, and groundwater), in order to establish the degree of non-point source pollution. Also, we assessed the relationship between the water-table depth and glyphosate and AMPA levels in groundwater. All of the studied compartments had variable levels of glyphosate and AMPA. The highest frequency of detections was found in the stream sediments samples (glyphosate 95%, AMPA 100%), followed by surface water (glyphosate 28%, AMPA 50%) and then groundwater (glyphosate 24%, AMPA 33%). Despite glyphosate being considered a molecule with low vertical mobility in soils, we found that its detection in groundwater was strongly associated with the month where glyphosate concentration in soil was the highest. However, we did not find a direct relation between groundwater table depth and glyphosate or AMPA detections. This is the first simultaneous study of glyphosate and AMPA seasonal variations in soil, groundwater, surface water, and sediments within a rural basin.

Medición de los niveles de ruido ambiental en la ciudad de Santiago de Chile / Environmental noise levels measurement of the city of Santiago, Chile

Introducción. Un estudio realizado en Santiago en 1989, estimó que 1.300.000 personas estaban sometidas a niveles de ruido inaceptables por las normas internacionales. Considerando que no existen publicaciones sobre ruido ambiental realizadas por otorrinolaringólogos, y que el tema no ha sido revisado en los últimos 15 años, quisimos actualizar la información al respecto. Material y método. Se evaluó el ruido en lugares que afectan la rutina del ciudadano común, independiente de su profesión: Barrio residencial, parques, discotecas, bar-discoteque, calles principales, buses de transporte urbano habituales, buses de transporte urbano del proyecto transantiago y Metro. Las mediciones se realizaron con un sonómetro integrador, según lo establecido por la normas de la Comisión Nacional del Medio Ambiente (CONAMA), durante los meses de julio a septiembre del 2006. Resultados. Las discotecas son el lugar con mayor contaminación acústica. En relación a la Avda . Bernardo O'Higgins (Alameda), el nivel de ruido: 80.5 dB(A), se mantiene constante en diferentes puntos de medición. Entre el transporte público, el metro tiene los niveles de ruido más altos: 87 dB (A). No existen diferencias entre los buses antiguos o micros amarillas y los del proyecto transantiago. Conclusiones. Nuestros resultados ponen una nota de alerta mostrando que el nivel de ruido en Santiago, para la gran mayoría de los parámetros, son superiores a las normas establecidas.

Introduction. A study carried out in Santiago in 1989 estimated that 1,300,000 people were exposed to noise levels unacceptable by international standards. Considering that there are no reports of environmental noise evaluations performed by otorhinolaryngologists, and that the subject has not been reviewed in the past 15 years, in this paper we present up-to-date information on the topic. Materials and methods. Noise levels were evaluated in several places that are part of the common citizen life, disregarding their profession: Residential neighborhoods, parks, discos, pubs, main streets, city buses (old and new system), and subway. Measurements were taken using an integrating sound level meter, according to CONAMA standards, between the months of July and September, 2006. Results. The highest noise pollution was found in discos. With regard to the main avenue in Santiago, Libertador B. O'Higgins, noise levels (80 dB (A)) remained constant in different measured points. As of public transportation, the subway had the higher noise levels (87 dB (A)). There were no differences between the old and new public transit buses. Conclusions. Our results raise an environmental alert, showing that the noise level in Santiago, for most parameters, is above international standards.

Contaminación sobre ruedas

Los autores plantean que el tránsito automotor es la mayor fuente de contaminación de la atmósfera de la ciudad de Buenos Aires. El INQUIMAE (Instituto de Química Física de los Materiales, Medio Ambiente y Energía) da un panorama de los distintos gases que intervienen en la contaminación del transporte automotor y su influencia en la calidad del aire y el ser humano

Contaminación sobre ruedas

Los autores plantean que el tránsito automotor es la mayor fuente de contaminación de la atmósfera de la ciudad de Buenos Aires. El INQUIMAE (Instituto de Química Física de los Materiales, Medio Ambiente y Energía) da un panorama de los distintos gases que intervienen en la contaminación del transporte automotor y su influencia en la calidad del aire y el ser humano

Catalizadores de tres vías para automóviles

Evaluación comparativa de la perfomance catalítica en laboratorio y en banco dinamométrico de catalizadores de tres vías,analizada dentro de un trabajo de desarrollo a escala piloto que se presenta como una alternativa para vigilar la calidad y durabilidad de los catalizadores presentes en los vehículos del mercado nacional

Catalizadores de tres vías para automóviles

Evaluación comparativa de la perfomance catalítica en laboratorio y en banco dinamométrico de catalizadores de tres vías,analizada dentro de un trabajo de desarrollo a escala piloto que se presenta como una alternativa para vigilar la calidad y durabilidad de los catalizadores presentes en los vehículos del mercado nacional

Peso pesado en la industria del reciclado de vehículos

Inauguración de la planta de procesamiento de vehículos y material ferrosos de Scrap Service