Air Pollution In Santiago Research Articles

Sources of Air Pollution Health Impacts and Co‐Benefits of Carbon Neutrality in Santiago, Chile

AbstractThe population of Santiago, Chile, experiences air pollution above global health guidelines that is attributable in part to large anthropogenic emissions. This is compounded by geographic features and meteorological conditions that are prone to pollution accumulation as well as secondary pollution production. In recent years, there have been improvements in air quality; however, the future of air pollution in Santiago remains unclear due to its growing population and increased vehicle use. Mitigation efforts can be supported by characterizing sources of air pollution and estimating how changes in emissions could affect air quality in future years. In this study, we conduct simulations using a chemical transport model (GEOS‐Chem) and perform adjoint calculations to characterize the relationship between health impacts associated with exposure to PM2.5, O3, and NO2 and anthropogenic emissions. We incorporate model updates in a new nested domain simulation over Central South America including local and regional anthropogenic emissions inventories for Chile. We estimate that 2,490 (1,360, 4,060) PM2.5‐ and O3‐related premature deaths and 5,350 (1,320, 11,330) NO2‐related new pediatric asthma cases were associated with pollution exposure in Santiago in 2015 and that a majority of these health impacts were attributable to anthropogenic emissions. We identify emissions from transportation, energy generation, and residential combustion as the leading contributors to these health impacts. Additionally, we estimate that Chile's commitment to attain carbon neutrality by 2050 could result in benefits in Santiago of 3,230 (1,240, 7,160) avoided deaths and 2,590 (640, 5,500) avoided pediatric asthma cases in 2050 compared to business‐as‐usual emissions.

Two decades of ozone standard exceedances in Santiago de Chile

A drastic decline of 2.4 ppbv decade−1 in the ozone mixing ratio has been measured in Santiago de Chile during the 2000s. Subsequently, in the 2010s, ozone trends stabilized in downtown and showed upward trends in eastern Santiago. The number of days with an 8-h average ozone mixing ratio above 61 ppbv, deemed harmful to health according to Chilean legislation, has declined significantly both in western and central Santiago. However, in eastern Santiago, one finds a 2010–2018 decade average of 43 days per year above recommended levels. Also, at a Receptor Site located ~ 70 km downwind from Santiago, this number rose to up to 3 months per year. A common denominator for the last two decades has been a steady increase in both gasoline and diesel-powered private cars. In the 2010s, the ozone weekend effect was frequently noted, providing evidence that the ozone formation regime in Santiago is VOC-limited. Nitrogen oxides and carbon monoxide (a proxy of anthropogenic VOCs) have increased steadily since 2014 in a relatively constant CO-to-NOx ratio. Therefore, we propose that primary emissions of NOX and VOCs from motor vehicle exhaust have remained as the main driver of the photochemical air pollution in Santiago as well as explaining the weekly variation. Santiago, like other megacities in the world, faces several challenges associated with increasing urbanization as well as the effects of climate change. An increasing population, growth in private car use, and urban sprawl have contributed to maintain high levels of ozone. New threats such as increasing temperatures observed in the central valleys of Chile, along with more frequent occurrences of heat waves, whose number has doubled in the last decade, will require a different approach to manage ozone pollution during the next decade. Santiago will not meet its own goals in the upcoming years without implementing robust, scientifically sound, and cost-effective strategies designed specifically to tackle photochemical pollution.

Impact of residential combustion and transport emissions on air pollution in Santiago during winter

Santiago (33.5°S, 70.5°W), the capital of Chile, is frequently affected by extreme air pollution events during wintertime deteriorating air quality (AQ) and thus affecting the health of its population. Intense residential heating and on-road transport emissions combined with poor circulation and vertical mixing are the main factors responsible for these events. A modelling system composed of a chemistry-transport model (CHIMERE) and a meteorological model (WRF) was implemented to assess the AQ impacts of residential and transportation sources in the Santiago basin. A two-week period of July 2015 with various days with poor AQ was simulated focusing on the impact on AQ with respect to fully inhalable particles (PM2.5) and nitrogen oxides (NOX). Three emission scenarios, within the range of targeted reductions of the decontamination plan of Santiago, were tested; namely 50% reduction of residential emission, 50% reduction of transport emissions and the combination of both. An additional scenario decreasing transport emissions in 10% was carried out to examine whether a linear dependence of surface concentrations on changes in emissions exists.The system was validated against surface and vertically resolved meteorological measurements. The model reproduces the daily surface concentration variability from the AQ monitoring network of Santiago. However, the model not fully captures the emissions variations inferred from the observations which may be due to missing sources such as resuspension of dust.Results show that, during the period studied, although both residential and transportation sources contribute to observed AQ levels in Santiago, reducing transport emissions is more effective in terms of reducing the number of days with pollution events than decreasing residential combustion. This difference in impact is largely due to the spatial distribution of the emission sources. While most of the residential combustion is emitted in the outskirts of the city, most of the transport emissions occur within the city, where most of the stations from AQ monitoring network of Santiago are located. As can be expected, the largest improvement of AQ in Santiago is achieved by the combined reduction of emissions in both sectors. Sensitivity analysis with 10% reduction in transport emissions reveals a linear behavior between emissions and concentrations for NOX and approximate linear behavior for PM2.5. The absence of secondary aerosols formation and dust resuspension in the current simulation could explain this deviation from linearity for fine particles. Nevertheless, it suggests that the results can be used for mitigation policies with emissions reductions below the 50% used in this study.

Research on Air Quality and Policy Response for Reducing Air Pollution in Santiago, Chile and Searching for Cooperation Issue between Korea and Chile

Research on Air Quality and Policy Response for Reducing Air Pollution in Santiago, Chile and Searching for Cooperation Issue between Korea and Chile

Respiratory disease and particulate air pollution in Santiago Chile: Contribution of erosion particles from fine sediments

Air pollution in Santiago is a serious problem every winter, causing thousands of cases of breathing problems within the population. With more than 6 million people and almost two million vehicles, this large city receives rainfall only during winters. Depending on the frequency of storms, statistics show that every time it rains, air quality improves for a couple of days, followed by extreme levels of air pollution. Current regulations focus mostly on PM10 and PM2.5, due to its strong influence on respiratory diseases. Though more than 50% of the ambient PM10s in Santiago is represented by soil particles, most of the efforts have been focused on the remaining 50%, i.e. particulate material originating from fossil and wood fuel combustion, among others. This document emphasizes the need for the creation of erosion/sediment control regulations in Chile, to decrease respiratory diseases on Chilean polluted cities.

‘Because in Chile [carbon] markets work!’ Exploring an experimental implementation of an emissions trading scheme to deal with industrial air pollution in Santiago

Emissions trading schemes have gained an important degree of momentum in recent years, rapidly becoming mainstream solutions to deal with the negative environmental consequences of human activity such as pollution and global warming. However there is still little empirical knowledge about what specific kind of work emissions trading schemes do. Using the analytical tools provided by science and technology studies, especially developments studying markets and economic practices, this paper looks to contribute to filling this void by exploring three kinds of work that emissions trading schemes might do: performing a textbook market of emissions permits, performing a civilized market in which a multitude of heterogeneous actors participate and as exemplars of the validity of certain economic knowledge. In order to explore the usability of this conceptualization the paper will then analyze one of earliest concrete implementations of this device: an emissions trading scheme introduced to deal with industrial air pollution in the city of Santiago (Chile) in the early 1990s. Through a historical genealogy, it will show this emissions trading scheme working not mainly as a textbook market, but as a civilized one and as a powerful exemplar that helped to mobilize both command-and-control regulation and neoliberal environmental economics to/from Chile and elsewhere.

Health risk estimation due to carbon monoxide pollution at different spatial levels in Santiago, Chile

The Metropolitan Region of Santiago has been declared as nonattainment area for carbon monoxide (CO). The data was based on seven air monitoring stations that do not necessarily represent the real population exposure. Usually, a series of coefficients that relates the concentration of pollutants with health effects (betas of the concentration-response equations) are used. For the calculation of these betas, normally, a city average air pollution concentration is used; nevertheless, these betas do not necessarily represent the real risk of exposure that the inhabitants are experimented. For this reason, this study estimates two aspects that are unknown and that are necessary to policymakers in public health decisions. First, estimate the exposure at a lower spatial resolution level and, second, estimate a concentration-response curve that differs spatially and depends on the proportion of susceptible groups. We followed the Air Pollution and Health, European Approach/Spanish Multicenter Study on the Relationship Between Air Pollution and the Mortality methodology for the determination of the short-term health effect due to CO population exposure at the three spatial levels (city, zone, and county). We found that there are different risks in cardiorespiratory mortality in the group over 64 years old associated to an unequal exposure to CO in Santiago city. The higher risks are in counties located to the south-east of the city. These finding confirm the necessity to face, in a different way, the approach when evaluating control strategies and policy decision to control air pollution in Santiago.

Tradable Permits in Developing Countries: Evidence from Air Pollution in Santiago, Chile

Santiago was one of the first cities outside the OECD to implement a tradable permit program to control air pollution. This paper looks closely at the program's performance over the past ten years, stressing its similarities and discrepancies with trading programs implemented in developed countries, and analyzing how it has reacted to regulatory adjustments and market shocks. Studying Santiago's experience allows us to discuss the drawbacks and advantages of applying tradable permits in less developed countries.

PAHs and Mutagenicity of Inhalable and Respirable Diesel Particulate Matter in Santiago, Chile

Delayed human effects such as cancer could be a consequence of chronic exposure, over long periods of time, to inhalable (PM10) and respirable (PM2.5) particles containing environmental carcinogen mixtures. Air pollution in Santiago, Chile, is a major public health problem due to the high levels of regulated pollutants such as PM10, CO, and ozone. In this work, we studied the levels of polycyclic aromatic hydrocarbons (PAHs) onto PM10 and PM2.5 collected in diesel revision plants, in an urban area with a high flow of buses and trucks and in a rural area not exposed to diesel emissions. The PM10 average levels in diesel emission plants were higher than the Chilean PM10 standard and higher than those found in the urban and rural areas. In the urban area the PM10 average levels were lower than the Chilean PM10 standard, although some 24 h levels surpassed the levels established to decree preemergency or emergency and in some cases were higher than the levels reported by all the official monitoring stations. The levels of total PAHs onto PM10 were higher in the diesel plants than in the urban area and rural area, but the levels of six carcinogenic PAHs were similar in the diesel plants to those found in the urban area. Organic extracts from PM10 collected in diesel plants in Salmonella typhimurium TA98 in the presence and in the absence of an S9 activation system were significantly higher than in the urban area and rural area. Mutagenic activity with and without S9 in diesel plants and the urban area showed that indirect (PAHs) and direct (nitro-PAHs) mutagenic compounds are present in organic extracts from PM10. In conclusion, these results showed that in Santiago diesel emission particles were highly mutagenic and contain carcinogenic PAHs. This might represent a risk for long-term respiratory effects in Santiago's inhabitants.

Robust estimates of value of a statistical life for developing economies

Environmental economists use the value-of-statistical-life (VSL) approach to value mortality changes resulting from environmental improvement. Because of scarce data, VSL estimates are unavailable for most developing countries. Using robust regression techniques, we conduct a meta-analysis of VSL studies in industrialized countries to derive a VSL prediction function for developing economies accounting for differences in risk, income, human capital levels, and other demographic characteristics of these economies. We apply our estimated VSL to assess the willingness to pay for reduction in mortality linked to air pollution in Santiago, Chile. We find willingness-to-pay estimates in the range of 1992 purchasing power parity (PPP) $519,000–675,000 per life.

Statistical modelling and prediction of atmospheric pollution by particulate material: two nonparametric approaches

Atmospheric particles are one of the main factors of air pollution in Santiago, Chile. Inhalation of particulate material is known to lead to serious health problems, including respiratory illness and complications related thereto. Vehicular traffic, industrial activity and street dust are important sources of atmospheric particles. The public authorities in Santiago have been monitoring air pollution by means of a network of semi-automatic sampling stations. At one of these stations, located near the city centre close to Government House, both PM2.5 and PM10 particulate material concentrations have been measured continuously for several years. Here PM2.5 refers to particles having a diameter smaller than 2.5 microns and PM10 corresponds to particles smaller than 10 microns. Hourly averages of the concentrations are available. For the present work, hourly data recorded at intervals of 12 hours have been used. The aim is to describe and forecast these variables with satisfactory precision, including critical pollution episodes, both as a function of previous behaviour and of a set of meteorological variables, comprising wind speed and direction, ambient temperature and relative air humidity. Both non-parametric discriminant analysis and multivariate adaptive regression splines procedures have been applied. Highly satisfactory classification as well as forecasting results were achieved with these approaches, respectively. Copyright © 2001 John Wiley & Sons, Ltd.

Rapid urban growth, land-use changes and air pollution in Santiago, Chile

This paper is a contribution to the understanding of the topoclimatic and environmental geography of the basin where Santiago — one of the most polluted Latin American city – is located. In the first part, land-use change is analysed looking at the climatic transformation caused by the rapid transit from natural semiarid surface to urban areas. In the second part, seasonal weather and daily cycles of slope winds and the available ventilation are described trying to relate those patterns with the spatial distribution of air pollution. A combination of meteorological, geographical and cultural factors explain extreme air pollution events: meteorologically, Santiago is under permanent subsidence inversion layers. Geographically, the city is located in a closed basin surrounded by mountains. Culturally, the urban area has the highest population concentration (40% of the national total), industries (near 70% of the total) and vehicles, which are the main sources of smog. The urban and suburban transport system is based on a large number of buses (diesel) and private cars, both experiencing a rapid growth from the past few years. The city and specially the transport system generates high emissions of pollutant, but the natural semiarid deforested soils and slopes are also important sources. The local wind system can explain the differential spatial distribution on the concentration of air pollutants in the city and its periphery. In winter (rain season) concentrations of particulate matter are higher at the centre and the SW part of the city. The andean piedmont area (E part of the city) shows minimum values, suggesting major ventilation effects of slope and valley winds. Ozone exceeds air quality standards in summer (dry season) at all sites in the centre and periphery. However, the O 3-concentrations are higher on preferred residential areas located at the piedmont area (E part of the city), suggesting air pollution transport effects. Currently, there is no consideration of these local climatic features in the process of urban planning.

Cost Estimates of Transport Air Pollution in Santiago, Chile

Findings from a study that attempts to monetize the costs of transport air pollution in Santiago, Chile, are presented. The costs per pollutant used in the study come from a 1994 World Bank study estimating morbidity and mortality costs of air pollution in Santiago, based on productivity losses and treatment costs. Using MOBILE-derived vehicle emissions factors and estimated vehicle distances traveled by various vehicle types, the total estimated transport pollution costs incurred in 1994 are presented. Also presented are estimated average air pollution costs per passenger kilometer traveled for pre- and post-EPA87 standard autos and taxis and pre–and post–EPA91 standard buses, as well as for Santiago’s Metro (urban heavy rail). Future air pollution trends in Santiago are discussed, and a theoretical discussion of the potential application of these cost estimates for transportation policy making in the city is provided.

Growing car ownership in LDCs: The impact on the environment and trade

Kahn recently completed a study with Suzi Kerr, sponsored by the Harvard Institute for International Development, on the causes and consequences of air pollution in Santiago, Chile. They explained how local air pollution in Santiago is linked to income growth. Although the rising number of cars indicates that the people of Santiago have become wealthier, the environment and the government are ill prepared for the consequences of increased air pollution, particularly for a lower quality of life, Kahn discusses the problem of growing car ownership rates in LDCs in a larger, global context, and lends insights into its implications for future trade with these countries.

Inhalable urban atmospheric particulate matter in a semi-arid climate: The case of Santiago De Chile

The city of Santiago is characterized by low average rainfall and atmospheric thermal inversion layers. Air pollution levels are high. Dichotomous sampling of inhalable particulate matter (IPM) has been conducted at a fixed station on the Universidad de Santiago de Chile (USACH) campus from October 1981 to March 1983. The air sampling inlet cutoff was 15 μm, the fractioning cut being located at a 2.5 μm aerodynamic diameter. The samples were analyzed qualitatively by X-ray fluorescence (XRF) spectrometry. Information on the IPM component of urban air pollution in Santiago by particle sizing sampling methods was not previously available, nor had XRF spectrometry been applied to local IPM samples. A multivariate statistical analysis of the body of data comprising sample masses and XRF elemental intensities is presented and discussed. The group of elements Al, Si, K, Ca, Ti and Fe shows strong statistical correlations in the coarse particle fraction; correlations in the fine particle fraction include Br/Pb. Evidence for seasonal variations in the air pollution pattern is presented. Pollution by sulfur is discussed.