2018 |
Morales, R G E; Toro, R; Morales, L; Leiva, M A Landfill Fire and Airborne Aerosols in a Large City: Lessons Learned and Future Needs Artículo de revista Air Quality Atmosphere and Health, 11 (1), pp. 111-121, 2018, ISSN: 1873-9318. Resumen | Enlaces | BibTeX | Etiquetas: air-quality, atmospheric combustion, dioxins, emissions, environmental chemistry, fire, impact, landfill municipal particulatematter, pollution, precipitation, santiago, sites solid solid-waste, urban vegetation, waste @article{RN416, title = {Landfill Fire and Airborne Aerosols in a Large City: Lessons Learned and Future Needs}, author = {R.G.E. Morales and R. Toro and L. Morales and M.A. Leiva}, url = {/brokenurl#<Go to ISI>://WOS:000422939300011}, doi = {10.1007/s11869-017-0522-8}, issn = {1873-9318}, year = {2018}, date = {2018-01-01}, journal = {Air Quality Atmosphere and Health}, volume = {11}, number = {1}, pages = {111-121}, abstract = {Landfill fires are relatively frequent incidents that can result in severe environmental impacts. On the morning of January 15, 2016, a fire occurred at the Santa Marta landfill (Lf) in the metropolitan area of Santiago (SMA), Chile. The fire triggered public alarm. In the present work, the impact of the landfill fire on the air quality of the SMA and the possible impacts on human health are analyzed. According to the information collected, the fire began after a collapse in the landfill on January 15, 2016. The fire could not be controlled by the Lf operating company, and authorities acted late in responding. The results revealed that at the focal point of the fire, particulate matter with an aerodynamic diameter smaller than 2.5 mu m (PM2.5) reached concentration levels on the order of 1000 mu g m(-3). Three days after the start of the fire, hourly PM2.5 concentration levels above 200 mu g m(-3) were recorded, at a distance approximately 20 km northeast of where the fire occurred. The PM2.5 concentration levels recommended for the protection of the health of vulnerable persons were subsequently exceeded. These results suggest that a preventive measure should have been the evacuation of the most pollution-sensitive population. An inappropriate management of the emergency was demonstrated. Legislation should be improved by stipulating which sanitary Lfs should be equipped with firefighting equipment. Territorial planning should be improved by considering geographic and meteorological aspects.}, keywords = {air-quality, atmospheric combustion, dioxins, emissions, environmental chemistry, fire, impact, landfill municipal particulatematter, pollution, precipitation, santiago, sites solid solid-waste, urban vegetation, waste}, pubstate = {published}, tppubtype = {article} } Landfill fires are relatively frequent incidents that can result in severe environmental impacts. On the morning of January 15, 2016, a fire occurred at the Santa Marta landfill (Lf) in the metropolitan area of Santiago (SMA), Chile. The fire triggered public alarm. In the present work, the impact of the landfill fire on the air quality of the SMA and the possible impacts on human health are analyzed. According to the information collected, the fire began after a collapse in the landfill on January 15, 2016. The fire could not be controlled by the Lf operating company, and authorities acted late in responding. The results revealed that at the focal point of the fire, particulate matter with an aerodynamic diameter smaller than 2.5 mu m (PM2.5) reached concentration levels on the order of 1000 mu g m(-3). Three days after the start of the fire, hourly PM2.5 concentration levels above 200 mu g m(-3) were recorded, at a distance approximately 20 km northeast of where the fire occurred. The PM2.5 concentration levels recommended for the protection of the health of vulnerable persons were subsequently exceeded. These results suggest that a preventive measure should have been the evacuation of the most pollution-sensitive population. An inappropriate management of the emergency was demonstrated. Legislation should be improved by stipulating which sanitary Lfs should be equipped with firefighting equipment. Territorial planning should be improved by considering geographic and meteorological aspects. |
Rojano, R E; Manzano, C A; Toro, R; Morales, R G E; Restrepo, G; Leiva, M A Potential Local and Regional Impacts of Particulate Matter Emitted from One of the World's Largest Open-Pit Coal Mines Artículo de revista Air Quality Atmosphere and Health, 11 (5), pp. 601-610, 2018, ISSN: 1873-9318. Resumen | Enlaces | BibTeX | Etiquetas: air-pollution, area, atmospheric cerrejon, china, cities colombia, environmental chemistry, episodes, health impact, long-range mining mining, open-pit origin, particulatematter, pm10, quality, temporal transport, trends @article{RN417, title = {Potential Local and Regional Impacts of Particulate Matter Emitted from One of the World's Largest Open-Pit Coal Mines}, author = { R.E. Rojano and C.A. Manzano and R. Toro and R.G.E. Morales and G. Restrepo and M.A. Leiva}, url = {/brokenurl#<Go to ISI>://WOS:000435421100011}, doi = {10.1007/s11869-017-0542-4}, issn = {1873-9318}, year = {2018}, date = {2018-01-01}, journal = {Air Quality Atmosphere and Health}, volume = {11}, number = {5}, pages = {601-610}, abstract = {This study was designed to evaluate the atmospheric total suspended particle (TSP) and particulate matter (PM10) concentrations and temporal variability in one of the world's largest open-pit coal mines (El Cerrejon) located in northeast Colombia, during 2012-2016. The results showed overall average TSP and PM10 concentrations of 86 mu g m (-3) (CI95% 84-88 mu g m (-3)) and 34 mu g m (-3) (CI95% 33-35 mu g m (-3)), respectively, with the highest concentrations between March and August each year. A time trend analysis of the results revealed that PM10 concentrations in particular have significantly increased between 6.2 and 7.7% per year (CI95% 1.2-12.8% year(-1)) in several of the monitoring stations. Meteorological parameters were also evaluated. It was observed that NE winds with speeds above 2 m s(-1) were significantly correlated with an increase in the concentration of PM10 for selected downwind sites, which suggested that coal mining operations are an important source of atmospheric PM in the area. Regional long-range atmospheric transport scenarios showed potential effects on neighboring municipalities and countries within 72-h transportation events. These highlighted the need to develop new strategies to control the emissions of PM from the local mining industry to comply with local and international guidelines and regulations, particularly when industrial expansion is planned for the near future and relatively large population centers are in the area, of which a high proportion belong to indigenous populations.}, keywords = {air-pollution, area, atmospheric cerrejon, china, cities colombia, environmental chemistry, episodes, health impact, long-range mining mining, open-pit origin, particulatematter, pm10, quality, temporal transport, trends}, pubstate = {published}, tppubtype = {article} } This study was designed to evaluate the atmospheric total suspended particle (TSP) and particulate matter (PM10) concentrations and temporal variability in one of the world's largest open-pit coal mines (El Cerrejon) located in northeast Colombia, during 2012-2016. The results showed overall average TSP and PM10 concentrations of 86 mu g m (-3) (CI95% 84-88 mu g m (-3)) and 34 mu g m (-3) (CI95% 33-35 mu g m (-3)), respectively, with the highest concentrations between March and August each year. A time trend analysis of the results revealed that PM10 concentrations in particular have significantly increased between 6.2 and 7.7% per year (CI95% 1.2-12.8% year(-1)) in several of the monitoring stations. Meteorological parameters were also evaluated. It was observed that NE winds with speeds above 2 m s(-1) were significantly correlated with an increase in the concentration of PM10 for selected downwind sites, which suggested that coal mining operations are an important source of atmospheric PM in the area. Regional long-range atmospheric transport scenarios showed potential effects on neighboring municipalities and countries within 72-h transportation events. These highlighted the need to develop new strategies to control the emissions of PM from the local mining industry to comply with local and international guidelines and regulations, particularly when industrial expansion is planned for the near future and relatively large population centers are in the area, of which a high proportion belong to indigenous populations. |
2017 |
Toro, R; Araya, C; Labra, F; Morales, L; Morales, R G E; Leiva, M A Trend and Recovery of the Total Ozone Column in South America and Antarctica Artículo de revista Climate Dynamics, 49 (11-12), pp. 3735-3752, 2017, ISSN: 0930-7575. Resumen | Enlaces | BibTeX | Etiquetas: analysis, arosa atmospheric chemistry, column, cycle, decadal depletion, dynamics, environmental chemistry, estimator, events, extratropical extreme interannual linear long-term multiple oscillation, ozone ozone, punta-arenas, quasi-biennial regression, sunspot theil-sen total trend variability, variation @article{RN374, title = {Trend and Recovery of the Total Ozone Column in South America and Antarctica}, author = { R. Toro and C. Araya and F. Labra and L. Morales and R.G.E. Morales and M.A. Leiva}, url = {/brokenurl#<Go to ISI>://WOS:000415579000006}, doi = {10.1007/s00382-017-3540-1}, issn = {0930-7575}, year = {2017}, date = {2017-01-01}, journal = {Climate Dynamics}, volume = {49}, number = {11-12}, pages = {3735-3752}, abstract = {South America is one of the most vulnerable areas to stratospheric ozone depletion; consequently, an increased amount of UV radiation reaches the Earth's surface in this region. In this study, we analyzed the long-term trend in the total ozone column (TOC) over the southern part of the South American continent from 1980 to 2009. The database used was obtained by combining several satellite measurements of the TOC on a 1A degrees (latitude) x 1.25A degrees (longitude) grid. Analysis of the long-term trend was performed by applying the Theil-Sen estimator and the Mann-Kendall significance test to the deseasonalized time series. The long-term trend was also analyzed over several highly populated urban zones in the study area. Finally, multiple linear regression (MLR) modeling was used to identify and quantify the drivers of interannual variability in the TOC over the study area with a pixel-by-pixel approach. The results showed a decrease in the TOC ranging from -0.3 to -4% dec(-1) from 1980 to 2009. On a decadal timescale, there is significant variability in this trend, and a decrease of more than -10% dec(-1) was found at high latitudes (1980-1989). However, the trends obtained over much of the study area were not statistically significant. Considering the period from 1980 to 1995, we found a decrease in the TOC of -2.0 +/- 0.6% dec(-1) at latitudes below 40A degrees S and -6.9 +/- 2.0% dec(-1) at latitudes above 40A degrees S, for a 99.9% confidence level over most of the study area. Analysis of the period from 1996 to 2009 showed a statistically significant increase of 2.3 +/- 0.1% dec(-1) at high latitudes (> 60A degrees S), confirming the initial TOC recovery in the Antarctic. Despite evidence for initial recovery of the TOC in some parts of the study area between 1996 and 2009, the long-term increase from September to November is not yet statistically significant. In addition, large parts of the study area and most of the urban areas continue to show a decreasing trend in the TOC. The MLR results show that at high latitudes, the main driver of interannual variability in the TOC is the total effective amount of halogens, followed by the eddy heat flux.}, keywords = {analysis, arosa atmospheric chemistry, column, cycle, decadal depletion, dynamics, environmental chemistry, estimator, events, extratropical extreme interannual linear long-term multiple oscillation, ozone ozone, punta-arenas, quasi-biennial regression, sunspot theil-sen total trend variability, variation}, pubstate = {published}, tppubtype = {article} } South America is one of the most vulnerable areas to stratospheric ozone depletion; consequently, an increased amount of UV radiation reaches the Earth's surface in this region. In this study, we analyzed the long-term trend in the total ozone column (TOC) over the southern part of the South American continent from 1980 to 2009. The database used was obtained by combining several satellite measurements of the TOC on a 1A degrees (latitude) x 1.25A degrees (longitude) grid. Analysis of the long-term trend was performed by applying the Theil-Sen estimator and the Mann-Kendall significance test to the deseasonalized time series. The long-term trend was also analyzed over several highly populated urban zones in the study area. Finally, multiple linear regression (MLR) modeling was used to identify and quantify the drivers of interannual variability in the TOC over the study area with a pixel-by-pixel approach. The results showed a decrease in the TOC ranging from -0.3 to -4% dec(-1) from 1980 to 2009. On a decadal timescale, there is significant variability in this trend, and a decrease of more than -10% dec(-1) was found at high latitudes (1980-1989). However, the trends obtained over much of the study area were not statistically significant. Considering the period from 1980 to 1995, we found a decrease in the TOC of -2.0 +/- 0.6% dec(-1) at latitudes below 40A degrees S and -6.9 +/- 2.0% dec(-1) at latitudes above 40A degrees S, for a 99.9% confidence level over most of the study area. Analysis of the period from 1996 to 2009 showed a statistically significant increase of 2.3 +/- 0.1% dec(-1) at high latitudes (> 60A degrees S), confirming the initial TOC recovery in the Antarctic. Despite evidence for initial recovery of the TOC in some parts of the study area between 1996 and 2009, the long-term increase from September to November is not yet statistically significant. In addition, large parts of the study area and most of the urban areas continue to show a decreasing trend in the TOC. The MLR results show that at high latitudes, the main driver of interannual variability in the TOC is the total effective amount of halogens, followed by the eddy heat flux. |
2015 |
Toro, R; Cordova, A; Canales, M; Morales, R G E; Mardones, P; Leiva, M A Trends and Threshold Exceedances Analysis of Airborne Pollen Concentrations in Metropolitan Santiago Chile Artículo de revista Plos One, 10 (5), 2015, ISSN: 1932-6203. Resumen | Enlaces | BibTeX | Etiquetas: allergic asthma, city, ciudad determinants, environmental chemistry, guidelines immunoglobulin-e, real, rhinitis, season, urban @article{toro2015trends, title = {Trends and Threshold Exceedances Analysis of Airborne Pollen Concentrations in Metropolitan Santiago Chile}, author = { R. Toro and A. Cordova and M. Canales and R.G.E. Morales and P. Mardones and M.A. Leiva}, url = {/brokenurl#<Go to ISI>://WOS:000354049700010}, doi = {10.1371/journal.pone.0123077}, issn = {1932-6203}, year = {2015}, date = {2015-01-01}, journal = {Plos One}, volume = {10}, number = {5}, abstract = {Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009-2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 +/- 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies.}, keywords = {allergic asthma, city, ciudad determinants, environmental chemistry, guidelines immunoglobulin-e, real, rhinitis, season, urban}, pubstate = {published}, tppubtype = {article} } Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009-2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 +/- 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies. |
Toro, R; Seguel, R J; Morales, R G E; Leiva, M A Ozone, Nitrogen Oxides, and Volatile Organic Compounds in a Central Zone of Chile Artículo de revista Air Quality Atmosphere and Health, 8 (6), pp. 545-557, 2015, ISSN: 1873-9318. Resumen | Enlaces | BibTeX | Etiquetas: air central chile, compound, environmental chemistry, izmir, organic ozone ozone, precursors, santiago, surface voc, volatile zone @article{RN221, title = {Ozone, Nitrogen Oxides, and Volatile Organic Compounds in a Central Zone of Chile}, author = { R. Toro and R.J. Seguel and R.G.E. Morales and M.A. Leiva}, url = {/brokenurl#<Go to ISI>://WOS:000362881100003}, doi = {10.1007/s11869-014-0306-3}, issn = {1873-9318}, year = {2015}, date = {2015-01-01}, journal = {Air Quality Atmosphere and Health}, volume = {8}, number = {6}, pages = {545-557}, abstract = {The relationships between ozone (O-3) and its precursors, nitrogen oxides (NO (x) ) and volatile organic compounds (VOCs), were investigated in the VIR region (34A degrees 10' S, 71A degrees 36' W), referred to as Libertador General Bernardo O'Higgins of Chile. Observations were obtained from a field study performed at four monitoring sites, which represented different environmental conditions, i.e., rural-coastal (Marchihue, MA), urban (Rancagua, RA, and Rengo, RE), and semi-urban (Codegua, CO) during the summer (between Feb 1 and Mar 12, 2010). Overall, greater O-3 concentrations were identified at the urban sites compared with the semi-urban and rural sites. In addition, the O-3 precursor concentrations were high in the early morning hours as a consequence of fresh vehicular emissions (from 11 to 40 ppbv for NO (x) and from 15 to 36 ppbC for VOC). The total VOC/NO (x) ratios at the study sites indicated that the formation of O-3 was limited by VOCs. Most O-3 was formed from ethene, isoprene, propene, 2-methylpropene, m- and p-xylenes, and toluene. These VOCs accounted for more than 50 % of the O-3 formation. The m- and p-xylene/ethylbenzene ratio confirmed the reception of aged air masses at the CO site. In contrast, at the RA site, the impact of pollution was primarily local. Control measures should be implemented to prevent O-3 exceedances of the National Ambient Air Quality Standard (NAAQS), despite the fact that the current O-3 concentrations do not exceed the current 8-h standard of 61 ppbv. These measures should include the control of VOC emissions and their chemical reactivity.}, keywords = {air central chile, compound, environmental chemistry, izmir, organic ozone ozone, precursors, santiago, surface voc, volatile zone}, pubstate = {published}, tppubtype = {article} } The relationships between ozone (O-3) and its precursors, nitrogen oxides (NO (x) ) and volatile organic compounds (VOCs), were investigated in the VIR region (34A degrees 10' S, 71A degrees 36' W), referred to as Libertador General Bernardo O'Higgins of Chile. Observations were obtained from a field study performed at four monitoring sites, which represented different environmental conditions, i.e., rural-coastal (Marchihue, MA), urban (Rancagua, RA, and Rengo, RE), and semi-urban (Codegua, CO) during the summer (between Feb 1 and Mar 12, 2010). Overall, greater O-3 concentrations were identified at the urban sites compared with the semi-urban and rural sites. In addition, the O-3 precursor concentrations were high in the early morning hours as a consequence of fresh vehicular emissions (from 11 to 40 ppbv for NO (x) and from 15 to 36 ppbC for VOC). The total VOC/NO (x) ratios at the study sites indicated that the formation of O-3 was limited by VOCs. Most O-3 was formed from ethene, isoprene, propene, 2-methylpropene, m- and p-xylenes, and toluene. These VOCs accounted for more than 50 % of the O-3 formation. The m- and p-xylene/ethylbenzene ratio confirmed the reception of aged air masses at the CO site. In contrast, at the RA site, the impact of pollution was primarily local. Control measures should be implemented to prevent O-3 exceedances of the National Ambient Air Quality Standard (NAAQS), despite the fact that the current O-3 concentrations do not exceed the current 8-h standard of 61 ppbv. These measures should include the control of VOC emissions and their chemical reactivity. |
Toro, A R; Campos, C; Molina, C; Morales, R G E; Leiva, M A Accuracy and Reliability of Chile's National Air Quality Information System for Measuring Particulate Matter: Beta Attenuation Monitoring Issue Artículo de revista Environment International, 82 , pp. 101-109, 2015, ISSN: 0160-4120. Resumen | Enlaces | BibTeX | Etiquetas: environmental chemistry, matter, megacities, model, monitoring, network, particulate pm10 pollution, quality santiago, system, temuco @article{RN270, title = {Accuracy and Reliability of Chile's National Air Quality Information System for Measuring Particulate Matter: Beta Attenuation Monitoring Issue}, author = { A.R. Toro and C. Campos and C. Molina and R.G.E. Morales and M.A. Leiva}, url = {/brokenurl#<Go to ISI>://WOS:000357909800013}, doi = {10.1016/j.envint.2015.02.009}, issn = {0160-4120}, year = {2015}, date = {2015-01-01}, journal = {Environment International}, volume = {82}, pages = {101-109}, publisher = {2015 Elsevier Ltd.}, abstract = {A critical analysis of Chile's National Air Quality Information System (NAQIS) is presented, focusing on particulate matter (PM) measurement. This paper examines the complexity, availability and reliability of monitoring station information, the implementation of control systems, the quality assurance protocols of the monitoring station data and the reliability of the measurement systems in areas highly polluted by particulate matter. From information available on the NAQIS website, it is possible to confirm that the PM2.5 (PM10) data available on the site correspond to 30.8% (69.2%) of the total information available from the monitoring stations. There is a lack of information regarding the measurement systems used to quantify air pollutants, most of the available data registers contain gaps, almost all of the information is categorized as "preliminary information" and neither standard operating procedures (operational and validation) nor assurance audits or quality control of the measurements are reported. In contrast, events that cause saturation of the monitoring detectors located in northern and southern Chile have been observed using beta attenuation monitoring. In these cases, it can only be concluded that the PM content is equal to or greater than the saturation concentration registered by the monitors and that the air quality indexes obtained from these measurements are underestimated. This occurrence has been observed in 12 (20) public and private stations where PM2.5 (PM10) is measured. The shortcomings of the NAQIS data have important repercussions for the conclusions obtained from the data and for how the data are used. However, these issues represent opportunities for improving the system to widen its use, incorporate comparison protocols between equipment install new stations and standardize the control system and quality assurance.}, keywords = {environmental chemistry, matter, megacities, model, monitoring, network, particulate pm10 pollution, quality santiago, system, temuco}, pubstate = {published}, tppubtype = {article} } A critical analysis of Chile's National Air Quality Information System (NAQIS) is presented, focusing on particulate matter (PM) measurement. This paper examines the complexity, availability and reliability of monitoring station information, the implementation of control systems, the quality assurance protocols of the monitoring station data and the reliability of the measurement systems in areas highly polluted by particulate matter. From information available on the NAQIS website, it is possible to confirm that the PM2.5 (PM10) data available on the site correspond to 30.8% (69.2%) of the total information available from the monitoring stations. There is a lack of information regarding the measurement systems used to quantify air pollutants, most of the available data registers contain gaps, almost all of the information is categorized as "preliminary information" and neither standard operating procedures (operational and validation) nor assurance audits or quality control of the measurements are reported. In contrast, events that cause saturation of the monitoring detectors located in northern and southern Chile have been observed using beta attenuation monitoring. In these cases, it can only be concluded that the PM content is equal to or greater than the saturation concentration registered by the monitors and that the air quality indexes obtained from these measurements are underestimated. This occurrence has been observed in 12 (20) public and private stations where PM2.5 (PM10) is measured. The shortcomings of the NAQIS data have important repercussions for the conclusions obtained from the data and for how the data are used. However, these issues represent opportunities for improving the system to widen its use, incorporate comparison protocols between equipment install new stations and standardize the control system and quality assurance. |
2014 |
Toro, R; Canales, M; Flocchini, R; Morales, R G E; Leiva, M A Urban Atmospheric Ammonia in Santiago City, Chile Artículo de revista Aerosol and Air Quality Research, 14 (1), pp. 33-44, 2014, ISSN: 1680-8584. Resumen | Enlaces | BibTeX | Etiquetas: air ammonia ammonia, chemistry, chile, emissions, environmental chemistry, gaseous new-york, nh3, nitrogen, particulate passive pm2.5, quality, samplers, santiago, secondary sulfate, uncertainty @article{toro2014urban, title = {Urban Atmospheric Ammonia in Santiago City, Chile}, author = { R. Toro and M. Canales and R. Flocchini and R.G.E. Morales and M.A. Leiva}, url = {/brokenurl#<Go to ISI>://WOS:000331789600004}, doi = {10.4209/aaqr.2012.07.0189}, issn = {1680-8584}, year = {2014}, date = {2014-01-01}, journal = {Aerosol and Air Quality Research}, volume = {14}, number = {1}, pages = {33-44}, abstract = {To improve the current understanding of the ammonia distribution in the major urban area of Chile, measurements of atmospheric NH3 were collected in Santiago during three sampling periods (25 April to 27 May, 11 to 26 June and 27 June to 31 July 2008). Additionally, air quality and meteorological data as well as NH4+, NO3-}, keywords = {air ammonia ammonia, chemistry, chile, emissions, environmental chemistry, gaseous new-york, nh3, nitrogen, particulate passive pm2.5, quality, samplers, santiago, secondary sulfate, uncertainty}, pubstate = {published}, tppubtype = {article} } To improve the current understanding of the ammonia distribution in the major urban area of Chile, measurements of atmospheric NH3 were collected in Santiago during three sampling periods (25 April to 27 May, 11 to 26 June and 27 June to 31 July 2008). Additionally, air quality and meteorological data as well as NH4+, NO3- |
Toro, R; Donoso, C S; Seguel, R A; Morales, R G E; Leiva, M A Photochemical Ozone Pollution in the Valparaiso Region, Chile Artículo de revista Air Quality Atmosphere and Health, 7 (1), pp. 1-11, 2014, ISSN: 1873-9318. Resumen | Enlaces | BibTeX | Etiquetas: control emissions, environmental chemistry, episode, formation hydrocarbons, non-methane nox, organic-compounds, ozone ozone, pollution-urban potential, regional, strategy, tropospheric volatile @article{RN219, title = {Photochemical Ozone Pollution in the Valparaiso Region, Chile}, author = { R. Toro and C.S. Donoso and R.A. Seguel and R.G.E. Morales and M.A. Leiva}, url = {/brokenurl#<Go to ISI>://WOS:000332712300001}, doi = {10.1007/s11869-013-0218-7}, issn = {1873-9318}, year = {2014}, date = {2014-01-01}, journal = {Air Quality Atmosphere and Health}, volume = {7}, number = {1}, pages = {1-11}, abstract = {The Valparaiso Region is characterized by the presence of air sheds that modulate the general atmospheric circulation with local winds. The ozone concentration in the region increases from the west coast toward the mountainous area, where the concentrations of ozone precursors are lower. In this study, surface ozone (O-3), nitric oxide, nitrogen dioxide, nitrogen oxide (NO (x) ), and volatile organic compounds (VOCs) were measured at four sites, including two upwind urban sites (Via del Mar (VM) and Villa Alemana (VA)), an upwind suburban site (Quillota (QU)) and a downwind semirural site (Los Andes (LA)) during 01 March-07 April 2010. The purpose of this study is to improve our understanding of the photochemistry of ozone in urban and semirural areas of the Valparaiso Region and the transport of ozone pollution in downwind rural areas. The results show that, in the VM and VA sites, higher concentrations of ozone precursors, NO (x) , and VOCs, are observed in the early morning hours, which is related to emissions from vehicle traffic, while comparatively lower ozone precursor concentrations are observed in QU and LA. In contrast, higher ozone concentrations are found in LA and QU, and lower concentrations are found in VM and VA. VOC analysis was performed by gas chromatography, and the results show that the VOC composition in the studied sites is similar to and coincident with vehicle emissions. An ozone formation regime limited by VOCs is found in the area. The leading contributors to the ozone-forming potential were ethene, propene, xylene, and toluene, which are also anthropogenic species and account for more than 70 % of O-3 formation. Thus, benzenes-toluene-xylenes played the most important role in O-3 formation, followed by alkenes, alkanes, aromatic, biogenic, and alkynes during the study periods. The m-, p-xylene/ethylbenzene relation confirms the reception of aged air masses in LA. The results of the present study demonstrate that ozone pollution is a regional problem and that O-3 regional transport is associated with such pollution. Finally, the results indicate the need to adopt mitigating measures for ozone pollution that consider the reactivity characteristics of VOCs.}, keywords = {control emissions, environmental chemistry, episode, formation hydrocarbons, non-methane nox, organic-compounds, ozone ozone, pollution-urban potential, regional, strategy, tropospheric volatile}, pubstate = {published}, tppubtype = {article} } The Valparaiso Region is characterized by the presence of air sheds that modulate the general atmospheric circulation with local winds. The ozone concentration in the region increases from the west coast toward the mountainous area, where the concentrations of ozone precursors are lower. In this study, surface ozone (O-3), nitric oxide, nitrogen dioxide, nitrogen oxide (NO (x) ), and volatile organic compounds (VOCs) were measured at four sites, including two upwind urban sites (Via del Mar (VM) and Villa Alemana (VA)), an upwind suburban site (Quillota (QU)) and a downwind semirural site (Los Andes (LA)) during 01 March-07 April 2010. The purpose of this study is to improve our understanding of the photochemistry of ozone in urban and semirural areas of the Valparaiso Region and the transport of ozone pollution in downwind rural areas. The results show that, in the VM and VA sites, higher concentrations of ozone precursors, NO (x) , and VOCs, are observed in the early morning hours, which is related to emissions from vehicle traffic, while comparatively lower ozone precursor concentrations are observed in QU and LA. In contrast, higher ozone concentrations are found in LA and QU, and lower concentrations are found in VM and VA. VOC analysis was performed by gas chromatography, and the results show that the VOC composition in the studied sites is similar to and coincident with vehicle emissions. An ozone formation regime limited by VOCs is found in the area. The leading contributors to the ozone-forming potential were ethene, propene, xylene, and toluene, which are also anthropogenic species and account for more than 70 % of O-3 formation. Thus, benzenes-toluene-xylenes played the most important role in O-3 formation, followed by alkenes, alkanes, aromatic, biogenic, and alkynes during the study periods. The m-, p-xylene/ethylbenzene relation confirms the reception of aged air masses in LA. The results of the present study demonstrate that ozone pollution is a regional problem and that O-3 regional transport is associated with such pollution. Finally, the results indicate the need to adopt mitigating measures for ozone pollution that consider the reactivity characteristics of VOCs. |
Toro, R; Flocchini, R; Morales, R G E; Leiva, M A Carbonaceous Aerosols in Fine Particulate Matter of Santiago Metropolitan Area, Chile Artículo de revista Scientific World Journal, 10.1155/2014/794590 , 2014, ISSN: 1537-744x. Resumen | Enlaces | BibTeX | Etiquetas: air black carbon, climate, elemental organic pm10, environmental chemistry, pm2.5, pollution, secondary urban, variability @article{RN216, title = {Carbonaceous Aerosols in Fine Particulate Matter of Santiago Metropolitan Area, Chile}, author = { R. Toro and R. Flocchini and R.G.E. Morales and M.A. Leiva}, url = {/brokenurl#<Go to ISI>://WOS:000330661100001}, doi = {10.1155/2014/794590}, issn = {1537-744x}, year = {2014}, date = {2014-01-01}, journal = {Scientific World Journal}, volume = {10.1155/2014/794590}, abstract = {Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002-2007), concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August) and warm (September to February) seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 +/- 41%) than in the warm season (44 +/- 18%). On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 mu g/m(3)) and the United States Environmental Protection Agency standard (15 mu g/m(3)) for fine particulate matter.}, keywords = {air black carbon, climate, elemental organic pm10, environmental chemistry, pm2.5, pollution, secondary urban, variability}, pubstate = {published}, tppubtype = {article} } Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002-2007), concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August) and warm (September to February) seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 +/- 41%) than in the warm season (44 +/- 18%). On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 mu g/m(3)) and the United States Environmental Protection Agency standard (15 mu g/m(3)) for fine particulate matter. |
Leiva, M A; Toro, R; Morales, R G E; Rios, M A; González, M R A Study of Water-Soluble Inorganic Ions in Size-Segregated Aerosols in Atmospheric Pollution Episode Artículo de revista International Journal of Environmental Science and Technology, 11 (2), pp. 437-448, 2014, ISSN: 1735-1472. Resumen | Enlaces | BibTeX | Etiquetas: air ammonia, ammonium, distribution, distributions, emissions, environmental chemistry, nitrate, particle-size particles, particulate pm2.5, secondary sulfate @article{RN220, title = {A Study of Water-Soluble Inorganic Ions in Size-Segregated Aerosols in Atmospheric Pollution Episode}, author = { M.A. Leiva and R. Toro and R.G.E. Morales and M.A. Rios and M.R. Gonz\'{a}lez}, url = {/brokenurl#<Go to ISI>://WOS:000331804300019}, doi = {10.1007/s13762-013-0221-4}, issn = {1735-1472}, year = {2014}, date = {2014-01-01}, journal = {International Journal of Environmental Science and Technology}, volume = {11}, number = {2}, pages = {437-448}, abstract = {Particulate matter, the main pollutant in the atmospheric environment of the Santiago city in winter, was analyzed by means of the major water-soluble ionic species obtained under critical episodes of pollution in 2003. The particulate matter samples were collected using the Micro-Orifice uniform deposit impactors, with eight impactor stages connected in series, and the ionic species in particulate matter samples at each stage was analyzed by ion chromatography. While sulfate ion and nitrate ion showed bi-modal distributions, peaking in the fine and coarse mode, ammonium ion displayed a bi-modal size distribution, peaking in the fine and ultra fine mode. The equivalent concentration ratio of ammonium to sulfate was 2.03 +/- 0.09, indicating the complete neutralization of sulfuric acid by ammonia. The excess ammonium ion was associated to nitrate ion. The study of the size distribution of water-soluble inorganic ions in particulate matter supports the notion that secondary aerosols play a significant role in the urban atmosphere.}, keywords = {air ammonia, ammonium, distribution, distributions, emissions, environmental chemistry, nitrate, particle-size particles, particulate pm2.5, secondary sulfate}, pubstate = {published}, tppubtype = {article} } Particulate matter, the main pollutant in the atmospheric environment of the Santiago city in winter, was analyzed by means of the major water-soluble ionic species obtained under critical episodes of pollution in 2003. The particulate matter samples were collected using the Micro-Orifice uniform deposit impactors, with eight impactor stages connected in series, and the ionic species in particulate matter samples at each stage was analyzed by ion chromatography. While sulfate ion and nitrate ion showed bi-modal distributions, peaking in the fine and coarse mode, ammonium ion displayed a bi-modal size distribution, peaking in the fine and ultra fine mode. The equivalent concentration ratio of ammonium to sulfate was 2.03 +/- 0.09, indicating the complete neutralization of sulfuric acid by ammonia. The excess ammonium ion was associated to nitrate ion. The study of the size distribution of water-soluble inorganic ions in particulate matter supports the notion that secondary aerosols play a significant role in the urban atmosphere. |
2013 |
Leiva, M A; Santibanez, D A; Ibarra, S; Matus, P; Seguel, R A Five-Year Study of Particulate Matter (Pm2.5) and Cerebrovascular Diseases Artículo de revista Environmental Pollution, 181 , pp. 1-6, 2013, ISSN: 0269-7491. Resumen | Enlaces | BibTeX | Etiquetas: ambient binomial cerebrovascular cities, daily disease, environmental chemistry, epidemiology, episode, hospital matter, mortality, negative particulate pm10 pollution, regression, santiago, visits @article{RN159, title = {A Five-Year Study of Particulate Matter (Pm2.5) and Cerebrovascular Diseases}, author = { M.A. Leiva and D.A. Santibanez and S. Ibarra and P. Matus and R. Seguel}, url = {/brokenurl#<Go to ISI>://WOS:000323807900001}, doi = {10.1016/j.envpol.2013.05.057}, issn = {0269-7491}, year = {2013}, date = {2013-01-01}, journal = {Environmental Pollution}, volume = {181}, pages = {1-6}, publisher = {2013 Elsevier Ltd.}, abstract = {Cerebrovascular accidents, or strokes, are the second leading cause of mortality and the leading cause of morbidity in both Chile and the rest of the world. However, the relationship between particulate matter pollution and strokes is not well characterized. The association between fine particle concentration and stroke admissions was studied. Data on hospital admissions due to cerebrovascular accidents were collected from the Ministry of Health. Air quality and meteorological data were taken from the Air Quality database of the Santiago Metropolitan Area. Santiago reported 33,624 stroke admissions between January 1, 2002 and December 30, 2006. PM2.5 concentration was markedly seasonal, increasing during the winter. This study found an association between PM2.5 exposure and hospital admissions for stroke; for every PM2.5 concentration increase of 10 mu g m(-3), the risk of emergency hospital admissions for cerebrovascular causes increased by 1.29% (95% CI 0.552%-2.03%).}, keywords = {ambient binomial cerebrovascular cities, daily disease, environmental chemistry, epidemiology, episode, hospital matter, mortality, negative particulate pm10 pollution, regression, santiago, visits}, pubstate = {published}, tppubtype = {article} } Cerebrovascular accidents, or strokes, are the second leading cause of mortality and the leading cause of morbidity in both Chile and the rest of the world. However, the relationship between particulate matter pollution and strokes is not well characterized. The association between fine particle concentration and stroke admissions was studied. Data on hospital admissions due to cerebrovascular accidents were collected from the Ministry of Health. Air quality and meteorological data were taken from the Air Quality database of the Santiago Metropolitan Area. Santiago reported 33,624 stroke admissions between January 1, 2002 and December 30, 2006. PM2.5 concentration was markedly seasonal, increasing during the winter. This study found an association between PM2.5 exposure and hospital admissions for stroke; for every PM2.5 concentration increase of 10 mu g m(-3), the risk of emergency hospital admissions for cerebrovascular causes increased by 1.29% (95% CI 0.552%-2.03%). |
Seguel, R J; Mancilla, C; Rondanelli, R; Leiva, M A; Morales, R G E Ozone Distribution in the Lower Troposphere over Complex Terrain in Central Chile Artículo de revista Journal of Geophysical Research-Atmospheres, 118 (7), pp. 2966-2980, 2013, ISSN: 2169-897x. Resumen | Enlaces | BibTeX | Etiquetas: boundary-layer, california, chemistry, chile, environmental chemistry, evolution, hydrocarbons, layer, metropolitan-area, model organic-compounds, ozone, ozonesondes, photochemical planetary residual santiago, smog, volatile @article{RN160, title = {Ozone Distribution in the Lower Troposphere over Complex Terrain in Central Chile}, author = { R.J. Seguel and C. Mancilla and R. Rondanelli and M.A. Leiva and R.G.E. Morales}, url = {/brokenurl#<Go to ISI>://WOS:000319618300021}, doi = {10.1002/jgrd.50293}, issn = {2169-897x}, year = {2013}, date = {2013-01-01}, journal = {Journal of Geophysical Research-Atmospheres}, volume = {118}, number = {7}, pages = {2966-2980}, abstract = {Observations were performed in 12 communities of Central Chile in order to determine the horizontal gradients of ozone in the Santiago Basin and surrounding valleys. Higher ozone mixing ratios were found northeast of the Santiago Basin and included east of the Aconcagua Valley (similar to 70km from Santiago) suggesting that photochemical pollution produced in Santiago is capable of passing through the Chacabuco mountain chain (similar to 1.3km) and have impact downwind from the regions with the largest NOx and VOC emissions. To complement existing surface observations, ozonesonde and tethersonde campaigns were performed in the Santiago Basin and the Aconcagua Valley. The results suggest ozone can accumulate in layers aloft (e.g., >102ppb at 2km) similarly to layers observed in complex topography coastal regions like Southern California. Layers of significant ozone concentrations having a near surface origin were observed above the mixed layer and below the subsidence inversion base. We propose that the ozone in this residual layer can be transported large distances (at least to 70km) to further penetrate into the local environment under conditions of a well-mixed boundary layer.}, keywords = {boundary-layer, california, chemistry, chile, environmental chemistry, evolution, hydrocarbons, layer, metropolitan-area, model organic-compounds, ozone, ozonesondes, photochemical planetary residual santiago, smog, volatile}, pubstate = {published}, tppubtype = {article} } Observations were performed in 12 communities of Central Chile in order to determine the horizontal gradients of ozone in the Santiago Basin and surrounding valleys. Higher ozone mixing ratios were found northeast of the Santiago Basin and included east of the Aconcagua Valley (similar to 70km from Santiago) suggesting that photochemical pollution produced in Santiago is capable of passing through the Chacabuco mountain chain (similar to 1.3km) and have impact downwind from the regions with the largest NOx and VOC emissions. To complement existing surface observations, ozonesonde and tethersonde campaigns were performed in the Santiago Basin and the Aconcagua Valley. The results suggest ozone can accumulate in layers aloft (e.g., >102ppb at 2km) similarly to layers observed in complex topography coastal regions like Southern California. Layers of significant ozone concentrations having a near surface origin were observed above the mixed layer and below the subsidence inversion base. We propose that the ozone in this residual layer can be transported large distances (at least to 70km) to further penetrate into the local environment under conditions of a well-mixed boundary layer. |
Leiva, M A; González, B; Vargas, D; Toro, R; Morales, R G E Estimating the Uncertainty in the Atmospheric Ammonia Concentration in an Urban Area by Ogawa Passive Samplers Artículo de revista Microchemical Journal, 110 , pp. 340-349, 2013, ISSN: 0026-265x. Resumen | Enlaces | BibTeX | Etiquetas: air, ambient ammonia atmospheric canada, concentration, environment, environmental chemistry, estimation, gum, nh3 ogawa ontario, particles, passive sampler, southern uncertainty @article{RN158, title = {Estimating the Uncertainty in the Atmospheric Ammonia Concentration in an Urban Area by Ogawa Passive Samplers}, author = { M.A. Leiva and B. Gonz\'{a}lez and D. Vargas and R. Toro and R.G.E. Morales}, url = {/brokenurl#<Go to ISI>://WOS:000326851200050}, doi = {10.1016/j.microc.2013.05.004}, issn = {0026-265x}, year = {2013}, date = {2013-01-01}, journal = {Microchemical Journal}, volume = {110}, pages = {340-349}, publisher = {2013 Elsevier B.V.}, abstract = {Ammonia, one of the ambient gasses that require environmental monitoring, is typically measured using a passive sampling method. The present work presents an evaluation of the uncertainty according to the Guide to the Expression of Uncertainty in Measurement for the measurement of the atmospheric ammonia concentration as determined by an Ogawa passive sampler, using a colorimetric method. The analytical results report the uncertainty only as a standard deviation of repeated measurements, but not all sources of uncertainty are considered. In this work, the major sources of uncertainty in the measurements are identified as contributions to the linear least-square regression lines, repeatability and recovery. The result, including the expanded uncertainty (k = 2) at a level of confidence of 95%, is 39.2%. The aforementioned results indicate that the Ogawa sampler can be successfully deployed to estimate the atmospheric NH3 and could find wide application in environmental monitoring. However, to obtain correct conclusions, the uncertainty in the measurements must be considered.}, keywords = {air, ambient ammonia atmospheric canada, concentration, environment, environmental chemistry, estimation, gum, nh3 ogawa ontario, particles, passive sampler, southern uncertainty}, pubstate = {published}, tppubtype = {article} } Ammonia, one of the ambient gasses that require environmental monitoring, is typically measured using a passive sampling method. The present work presents an evaluation of the uncertainty according to the Guide to the Expression of Uncertainty in Measurement for the measurement of the atmospheric ammonia concentration as determined by an Ogawa passive sampler, using a colorimetric method. The analytical results report the uncertainty only as a standard deviation of repeated measurements, but not all sources of uncertainty are considered. In this work, the major sources of uncertainty in the measurements are identified as contributions to the linear least-square regression lines, repeatability and recovery. The result, including the expanded uncertainty (k = 2) at a level of confidence of 95%, is 39.2%. The aforementioned results indicate that the Ogawa sampler can be successfully deployed to estimate the atmospheric NH3 and could find wide application in environmental monitoring. However, to obtain correct conclusions, the uncertainty in the measurements must be considered. |
Leiva, M A; Morales, S; Segura, R Water Air and Soil Pollution, 224 (2), 2013, ISSN: 0049-6979. Resumen | Enlaces | BibTeX | Etiquetas: compliance, emissions, environmental chemistry, fish, fluorescence impact, in measurement mercury samples, sediments, soil, spectrometry, standards uncertainty, validation @article{RN162, title = {Comparative Measurements and Their Compliance with Standards of Total Mercury Analysis in Soil by Cold Vapour and Thermal Decomposition, Amalgamation and Atomic Absorption Spectrometry}, author = { M.A. Leiva and S. Morales and R. Segura}, url = {/brokenurl#<Go to ISI>://WOS:000315281300006}, doi = {10.1007/s11270-012-1390-3}, issn = {0049-6979}, year = {2013}, date = {2013-01-01}, journal = {Water Air and Soil Pollution}, volume = {224}, number = {2}, abstract = {Two methods to measure mercury concentration in soil are compared, and their compliance with international standards is determined: cold vapour atomic absorption spectrometry and thermal decomposition, amalgamation and atomic absorption spectrophotometry. The detection limit, quantification limit and uncertainty of these two analytical methods were evaluated and compared. The results indicated that thermal decomposition, amalgamation and atomic absorption spectrophotometry had a lower quantification limit and uncertainty than cold vapour atomic absorption spectrometry (quantification limit, 0.27 vs. 0.63 mg kg(-1); expanded uncertainty, 9.30 % vs. 10.8 %, respectively). Thermal decomposition, amalgamation and atomic absorption spectrophotometry allowed the determination of the base values for the concentration of mercury in soil recommended by international standards, achieving a lower detection limit than cold vapour atomic absorption spectrometry under the study conditions. In addition, thermal decomposition, amalgamation and atomic absorption spectrophotometry represent a more environmentally friendly alternative for mercury determination because this method uses fewer reagents and therefore generates less waste.}, keywords = {compliance, emissions, environmental chemistry, fish, fluorescence impact, in measurement mercury samples, sediments, soil, spectrometry, standards uncertainty, validation}, pubstate = {published}, tppubtype = {article} } Two methods to measure mercury concentration in soil are compared, and their compliance with international standards is determined: cold vapour atomic absorption spectrometry and thermal decomposition, amalgamation and atomic absorption spectrophotometry. The detection limit, quantification limit and uncertainty of these two analytical methods were evaluated and compared. The results indicated that thermal decomposition, amalgamation and atomic absorption spectrophotometry had a lower quantification limit and uncertainty than cold vapour atomic absorption spectrometry (quantification limit, 0.27 vs. 0.63 mg kg(-1); expanded uncertainty, 9.30 % vs. 10.8 %, respectively). Thermal decomposition, amalgamation and atomic absorption spectrophotometry allowed the determination of the base values for the concentration of mercury in soil recommended by international standards, achieving a lower detection limit than cold vapour atomic absorption spectrometry under the study conditions. In addition, thermal decomposition, amalgamation and atomic absorption spectrophotometry represent a more environmentally friendly alternative for mercury determination because this method uses fewer reagents and therefore generates less waste. |
Leiva, M A; Morales, R G E Environmental Assessment of Mercury Pollution in Urban Tailings from Gold Mining Artículo de revista Ecotoxicology and Environmental Safety, 90 , pp. 167-173, 2013, ISSN: 0147-6513. Resumen | Enlaces | BibTeX | Etiquetas: assessment, contamination, environmental chemistry, gold gum health, mercury mining, soil, standard uncertainty @article{RN161, title = {Environmental Assessment of Mercury Pollution in Urban Tailings from Gold Mining}, author = { M.A. Leiva and R.G.E. Morales}, url = {/brokenurl#<Go to ISI>://WOS:000315840000024}, doi = {10.1016/j.ecoenv.2012.12.026}, issn = {0147-6513}, year = {2013}, date = {2013-01-01}, journal = {Ecotoxicology and Environmental Safety}, volume = {90}, pages = {167-173}, publisher = {2013 Elsevier Inc.}, abstract = {It is well-known that small-scale artisanal mining is a source of mercury emissions into the environment, mainly from the use of rudimentary technologies that use mercury amalgamation in the extraction process. Mines near Andacollo, which is located in the Coquimbo region of Chile, use primitive methods to mine gold and copper. In this study, we determined the mercury content of gold mining wastes from Andacollo. At each site, we randomly sampled the soil at the surface and at a depth of 2 m following the ISO 10381 guidelines. Mercury analysis was performed with a direct mercury analyzer. At least one site was contaminated at a mercury concentration of 13.6 +/- 1.4 mg kg(-1), which was above the international recommendations that were set by the Canadian Council of Ministers of the Environment's soil quality guidelines (CA-SQG) and the Dutch guidelines (NL-RIVM). At least four of the fourteen sites in this study were within the control and tolerance levels of these recommendations. Better characterization of these sites is required to establish whether they represent a risk to the local community. Based on the US-EPA recommendations, which have a higher tolerance limit, none of the fourteen sites should pose a risk to humans.}, keywords = {assessment, contamination, environmental chemistry, gold gum health, mercury mining, soil, standard uncertainty}, pubstate = {published}, tppubtype = {article} } It is well-known that small-scale artisanal mining is a source of mercury emissions into the environment, mainly from the use of rudimentary technologies that use mercury amalgamation in the extraction process. Mines near Andacollo, which is located in the Coquimbo region of Chile, use primitive methods to mine gold and copper. In this study, we determined the mercury content of gold mining wastes from Andacollo. At each site, we randomly sampled the soil at the surface and at a depth of 2 m following the ISO 10381 guidelines. Mercury analysis was performed with a direct mercury analyzer. At least one site was contaminated at a mercury concentration of 13.6 +/- 1.4 mg kg(-1), which was above the international recommendations that were set by the Canadian Council of Ministers of the Environment's soil quality guidelines (CA-SQG) and the Dutch guidelines (NL-RIVM). At least four of the fourteen sites in this study were within the control and tolerance levels of these recommendations. Better characterization of these sites is required to establish whether they represent a risk to the local community. Based on the US-EPA recommendations, which have a higher tolerance limit, none of the fourteen sites should pose a risk to humans. |
2012 |
Seguel, R J; Morales, R G E; Leiva, M A Ozone Weekend Effect in Santiago, Chile Artículo de revista Environmental Pollution, 162 , pp. 72-79, 2012, ISSN: 0269-7491. Resumen | Enlaces | BibTeX | Etiquetas: effect, environmental chemistry, focus, nox ozone, phoenix, photochemistry, ratio, surface voc/nox weekday, weekend @article{RN35d, title = {Ozone Weekend Effect in Santiago, Chile}, author = { R.J. Seguel and R.G.E. Morales and M.A. Leiva}, url = {/brokenurl#<Go to ISI>://WOS:000301087800009}, doi = {10.1016/j.envpol.2011.10.019}, issn = {0269-7491}, year = {2012}, date = {2012-01-01}, journal = {Environmental Pollution}, volume = {162}, pages = {72-79}, publisher = {2011 Elsevier Ltd.}, abstract = {The study examined weekday-weekend differences in ozone, NOx (NO and NO2) and VOC concentrations in Santiago, Chile, from 1999 to 2007. The results provide evidence for the occurrence of an atmospheric phenomenon that produces higher ozone concentrations during weekends despite lower concentrations of ozone precursors. This phenomenon is known as the weekend effect (WE)., The overall ozone decrease since the spring of 2004 was a consequence of the implementation of several urban pollution control measures. Although these measures caused a decline in the number of days that exceed the national standard from two-thirds to one-third of summer days, the WE, which became statistically significant beginning in September 2004, could not be eliminated. Furthermore. VOC/NOx ratios decreased during the same period (2004), especially in the most industrialized area of Santiago. Similarly, under these regimes, the VOC/NOx ratios were higher on Sundays than on weekdays and caused higher ozone concentrations on Sundays.}, keywords = {effect, environmental chemistry, focus, nox ozone, phoenix, photochemistry, ratio, surface voc/nox weekday, weekend}, pubstate = {published}, tppubtype = {article} } The study examined weekday-weekend differences in ozone, NOx (NO and NO2) and VOC concentrations in Santiago, Chile, from 1999 to 2007. The results provide evidence for the occurrence of an atmospheric phenomenon that produces higher ozone concentrations during weekends despite lower concentrations of ozone precursors. This phenomenon is known as the weekend effect (WE)., The overall ozone decrease since the spring of 2004 was a consequence of the implementation of several urban pollution control measures. Although these measures caused a decline in the number of days that exceed the national standard from two-thirds to one-third of summer days, the WE, which became statistically significant beginning in September 2004, could not be eliminated. Furthermore. VOC/NOx ratios decreased during the same period (2004), especially in the most industrialized area of Santiago. Similarly, under these regimes, the VOC/NOx ratios were higher on Sundays than on weekdays and caused higher ozone concentrations on Sundays. |
2018 |
Landfill Fire and Airborne Aerosols in a Large City: Lessons Learned and Future Needs Artículo de revista Air Quality Atmosphere and Health, 11 (1), pp. 111-121, 2018, ISSN: 1873-9318. |
Potential Local and Regional Impacts of Particulate Matter Emitted from One of the World's Largest Open-Pit Coal Mines Artículo de revista Air Quality Atmosphere and Health, 11 (5), pp. 601-610, 2018, ISSN: 1873-9318. |
2017 |
Trend and Recovery of the Total Ozone Column in South America and Antarctica Artículo de revista Climate Dynamics, 49 (11-12), pp. 3735-3752, 2017, ISSN: 0930-7575. |
2015 |
Trends and Threshold Exceedances Analysis of Airborne Pollen Concentrations in Metropolitan Santiago Chile Artículo de revista Plos One, 10 (5), 2015, ISSN: 1932-6203. |
Ozone, Nitrogen Oxides, and Volatile Organic Compounds in a Central Zone of Chile Artículo de revista Air Quality Atmosphere and Health, 8 (6), pp. 545-557, 2015, ISSN: 1873-9318. |
Accuracy and Reliability of Chile's National Air Quality Information System for Measuring Particulate Matter: Beta Attenuation Monitoring Issue Artículo de revista Environment International, 82 , pp. 101-109, 2015, ISSN: 0160-4120. |
2014 |
Urban Atmospheric Ammonia in Santiago City, Chile Artículo de revista Aerosol and Air Quality Research, 14 (1), pp. 33-44, 2014, ISSN: 1680-8584. |
Photochemical Ozone Pollution in the Valparaiso Region, Chile Artículo de revista Air Quality Atmosphere and Health, 7 (1), pp. 1-11, 2014, ISSN: 1873-9318. |
Carbonaceous Aerosols in Fine Particulate Matter of Santiago Metropolitan Area, Chile Artículo de revista Scientific World Journal, 10.1155/2014/794590 , 2014, ISSN: 1537-744x. |
A Study of Water-Soluble Inorganic Ions in Size-Segregated Aerosols in Atmospheric Pollution Episode Artículo de revista International Journal of Environmental Science and Technology, 11 (2), pp. 437-448, 2014, ISSN: 1735-1472. |
2013 |
A Five-Year Study of Particulate Matter (Pm2.5) and Cerebrovascular Diseases Artículo de revista Environmental Pollution, 181 , pp. 1-6, 2013, ISSN: 0269-7491. |
Ozone Distribution in the Lower Troposphere over Complex Terrain in Central Chile Artículo de revista Journal of Geophysical Research-Atmospheres, 118 (7), pp. 2966-2980, 2013, ISSN: 2169-897x. |
Estimating the Uncertainty in the Atmospheric Ammonia Concentration in an Urban Area by Ogawa Passive Samplers Artículo de revista Microchemical Journal, 110 , pp. 340-349, 2013, ISSN: 0026-265x. |
Water Air and Soil Pollution, 224 (2), 2013, ISSN: 0049-6979. |
Environmental Assessment of Mercury Pollution in Urban Tailings from Gold Mining Artículo de revista Ecotoxicology and Environmental Safety, 90 , pp. 167-173, 2013, ISSN: 0147-6513. |
2012 |
Ozone Weekend Effect in Santiago, Chile Artículo de revista Environmental Pollution, 162 , pp. 72-79, 2012, ISSN: 0269-7491. |