em • feature by Luis Díaz-Robles, Herman Saavedra, Luis Schiappacasse, and F. Cereceda-Balic Luis Díaz-Robles, Herman Saavedra, and Luis Schiappacasse are with the Air Quality Unit at the Catholic University of Temuco in Chile. F. Cereceda-Balic is with Environmental Technology Center (CETAM in Spanish) at the Universidad Técnica Federico Santa María in Chile. E-mail: [email protected]. The Air Quality in Chile: Today, with a population of 16 million, Chile is one of South America’s most stable and prosperous nations.1 It leads Latin America in human development, competitiveness, income per capita, globalization, economic freedom, low perception of corruption, and state of peace.2 It also ranks high regionally in terms of freedom of the press and democratic development. Its economy is recovering fast from the last global economy recession, growing by 5.2% in 2010. The Monthly Economic Activity Grow Index for March 2011 was 15.2%, the highest value since 1992.3 In May 2010, Chile became the first South American country to join the Organization for Economic Co-operation and Development (OECD). However, Chile has serious air quality problems. Cerro Alegre Hill, Valparaiso, Chile. 28 em august 2011 Copyright 2011 Air & Waste Management Association awma.org 20 Years of Challenge Geography and Climate Chile occupies a long, narrow coastal strip between the Andes Mountains to the east and the Pacific Ocean to the west, with small mountains in the center of the country, called the Coast Mountains. Its climate varies, ranging from the world’s driest desert in the north, through a Mediterranean-like climate in the central region, to a rainy climate in the south. The northern desert contains great mineral wealth. The relatively small central region dominates in terms of population and agricultural resources, where the main cities are located between the Andes and the Coast Mountains. Southern Chile is rich in forests and grazing lands and features a string of volcanoes and lakes. Weather patterns of the majority of cities in Chile located in the central depression are detrimental to the pollutants removal from airshed, especially during fall and winter. The presence of the Pacific subtropical anticyclone marks for much of the year the emergence of the phenomenon of temperature inversion and a heavy coastal fog (called “vaguada costera” in Spanish). This favors the generation of a very stable layer of air near the surface, which inhibits turbulence and vertical air movement in these basins. During the summer, surface heating allows the erosion of the inversion layer on the airshed, resulting in a significant improvement in ventilation. However, emissions of nitrogen oxides (NOx) and volatile Map of Chile. organic compounds (VOCs) mainly from mobile sources, as well as the solar radiation, favor the formation of ozone in the cities of Santiago and Rancagua in central Chile. This article presents an overview of the Chilean air quality standards and the regions that are in exceedance of the air quality standards, as well as a broad picture of the air quality trends in Chile based on available monitoring data. Table 1. Chilean National Ambient Air Quality Standards. Pollutant Primary Standards Level 3 Averaging Time a Secondary Standards Level Averaging Time CO 9 ppm (10 mg/m ) 26 ppm (30 mg/m3) 8-hr 1-hr a None None Pb 0.5 μg/m3 b Annual (arithmetic average) None None c NO2 53 ppb 213 ppb Annual (arithmetic average) 1-hr d None None None None PM10 150 μg/m3 50 μg/m3 24-hr e Annual f (arithmetic average) None None None None PM2.5 50 μg/m3 20 μg/m3 24-hr e Annual f (arithmetic average) None None None None O3 0.061 ppm 8-hr g None None SO2 0.031 ppm 0.096 ppm none Annual h (arithmetic average) 24-hr i 0.031 ppm North Zone 0.023 ppm South Zone Annual h (arithmetic average) 0.140 ppm North Zone 0.099 ppm South Zone 24-hr j 0.382 ppm North Zone 0.268 ppm South Zone 1-hr k Notes: aThe three-year average of the 99th percentile of the daily maximum 8-hr or 1-hr concentration must not exceed 9 parts per million (ppm) or 1 ppm, respectively. bThe two-year average concentration must not exceed 0.5 μg/m3. cThe three-year average concentration must not exceed 53 parts per billion (ppb). dThe three-year average of the 99th percentile of the daily maximum 1-hr average must not exceed 213 ppb. eNot to be exceeded more than seven times per year. fThe three-year average of the weighted annual mean concentration must not exceed the standard. gThe three-year average of the 99th percentile of the daily maximum 8-hr average must not exceed 61 ppb. hThe three-year average of the weighted annual mean concentration must not exceed the respective standard. iThe three-year average of the 99th percentile of the 24-hr concentrations must not exceed 96 ppb. jThe three-year average of the 99.7th percentile of the 24-hr concentrations must not exceed the respective level. kThe three-year average of the 99.73th percentile of the 1-hr concentrations must not exceed the respective level. awma.org awma.org Copyright 2011 Air & Waste Management Association august 2011em august 2011 em2929 health, while the secondary standards are designed to protect the ecosystems (see Table 1). Figure 1. Annual minimum, maximum, and mean average SO2 concentrations based on 12 sites in the northern and central regions of Chile, 1993 to 2009. Chilean Standards The Chilean Air Quality Standards have been defined (and have not changed) since 1994, due to the creation of CONAMA (the Chilean equivalent of the U.S Environmental Protection Agency) the same year, and set both primary and secondary concentration limits for air pollutants. The primary standards are designed to protect the human Similar to the United States, areas that are in exceedance of the standards are designated as non-attainment areas. The designation of a nonattainment area contains the precise geographic area it spans. But there are some differences between the United States and Chile. In Chile, an area is designated as a “latent” non-attainment area, when the pollutant concentrations are between 80 and 100% of the standard, and as a “saturated” non-attainment area, when the pollutant concentration exceeds the set standard. These designations of latent or saturated area form the basis of the atmospheric prevention plans (APP) or atmospheric decontamination plans (ADP), respectively. These plans are similar in scope to the U.S. State Implementation Plans (SIPs). Latent and Saturated Areas in Chile The atmospheric contamination problem was, for many years, almost exclusively limited to Santiago; however, many mining zones and other northern, central, and southern cities in Chile have begun to Table 2. Chilean zones with severe air quality problems. Area Designation Pollutants Plan/Year a Antofagasta Tocopilla City Saturated Zone, 2007 PM10 ADP in elaboration Antofagasta Surrounding zone of CODELCO’s Chuquicamata Foundry Saturated Zone, 1991 PM10, SO2 ADP, 1993, 2001 Atacama Surrounding zone of CODELCO’s Potrerillos Foundry, Salvador Division Saturated Zone, 1997 PM10, SO2 ADP, 1999 Atacama Surrounding zone of Hernán Videla Lira Foundry, Tierra Amarilla and Copiapó cities Saturated Zone, 1993 SO2 ADP, 1995 Coquimbo Andacollo city Saturated Zone, 2009 PM10 ADP in elaboration Valparaíso Vantanas Industiral Complex of Puchuncaví and Quintero cities Saturated Zone, 1993 PM10, SO2 ADP, 1993 Metropolitan Region of Santiago Santiago Metropolitan area Saturated Zone Latent Zone PM10, O3, SO2 NO2 ADPP b, 1996, 2004, 2010 Bernardo O’Higgins Surrounding zone of Caletones Founfry, el CODELCO’s el Teniente Division, Mostazal, Codegua, Machalí, and Requínoa cities Saturated Zone, 1994 PM10, SO2 Rancagua city Saturated Zone, 2009 Region Northern Chile Central Chile Bernardo O’Higgins ADP in elaboration PM10 ADP in elaboration Southern Chile Maule Talca city Saturated Zone, 2010 PM10 Biobío Concepción Metropolitan area Latent Zone, 2007 PM10 ADP in elaboration Araucanía Temuco City and Padre Las Casas Saturated Zone, 2005 PM10 APP in process ADP, 2010 Notes: aYear enacted and subsequent revision years; bADPP = Atmospheric Decontamination and Prevention Plan. 3030em emaugust august 2011 2011 Copyright 2011 Air & Waste Management Association awma.org awma.org show air quality problems, with severe health consequences for the population. Table 2 shows that the atmospheric contamination problem in the main non-attainment regions in Chilean urban and mining northern zones is largely due to the high levels of sulfur dioxide (SO2) and particulate matter (PM10) from copper foundries and coal-burning power plants; in the central zone, the concerns are due to PM10, ozone (O3), and SO2 coming from mobile and point sources; while in Chilean southern urban zones, the main pollutant is PM10 produced by residential wood combustion (RWC). Besides these zones that have been declared as saturated or latent, there are some cities in southern Chile (e.g., Chillán, Coyhaique, Talca, Valdivia, and Osorno), where PM10 monitoring studies and campaigns have started showing alarming air quality results, compared with those from Temuco city.4 These non-attainment zones cover approximately 40,000 km2, where approximately 6,800,000 inhabitants are exposed to air pollution. Air Quality Trends The specific geographical and meteorological conditions of Chile, plus the anthropogenic emissions have resulted in high atmospheric levels of PM10, PM2.5, O3 and SO2, and remain a severe problem since the 1990s. As a result, communities exposed to high concentrations of these pollutants have been associated with a rise in mortality and morbidity.5-29 Fortunately, in some industrial centers and cities, pollution levels have drastically decreased by the measures established in Chilean regulations. For example, the annual SO2 concentrations in the copper mining areas of the north and central regions of Chile decreased substantially (by 77%) from 1993 to 2009 (see Figure 1). However, the concentrations of SO2 have remained flat or increased from 2004 to 2009 due to the construction of more coal power plants as a result of the expansion of the copper industry and its demand for energy. billion by volume (ppbv) 8-hr moving average of Figure 2. Annual average concentrations of PM10 and 2009 in Santiago.30 PM2.5 (in µg/m3) in SantiIn some southern urban zones, the control meas- ago, Chile, 1989-2009. ures have not been as successful as in Santiago, because the sources are different and the ADP began only in 2010. Temuco, for example, has serious PM problems due to RWC. Since 2002, this city has experienced degrading air quality (see Figure 2), with PM10 concentrations increasing each year, and exceeding the annual and daily standards systematically, becoming worse each year.31 Temuco’s ADP and the National Strategy to control de RWC smoke were implemented in 2010 to help solve this problem. Figure 3. Air quality in Temuco (a) PM10 annual average and (b) 98 percentile and maximum of Since 1991, the air quality research in Chile has 24-hr. Past Research Focus and Future Needs focused initially on data analysis,32-34 and health effects for short-term exposure.21, 26-29 Subsequently, Source: Chilean Environmental Ministry. Figure 2 shows the evolution of air quality in Santiago, from 1989 to 2009, where annual average concentrations of PM10 and PM2.5 decreased by 33% and 54%, respectively. The percentage of PM10 reduction was less than PM2.5 because the coarse fraction emitted by non-point sources (like RWC) has experienced an increase of 11%. The O3 is still high with a maximum of 93 parts per awma.org Copyright 2011 Air & Waste Management Association august 2011 em 31 it has expanded to important research topics in establishing and improving forecasting models,31, 35-40 emission inventories and air quality photochemical modeling,41-51 receptor models,52-55 increased studies in health effects for cardio-respiratory diseases produced by PM and carbon monoxide exposure in Santiago, Temuco, Talcahuano, and Hualpén,5-15 policy-making studies,34, 56-61 indoor air quality,56 and chemical description and monitoring networks.32-33, 46, 62-74 While past research has contributed to our understanding, it is obvious that more research is needed to develop better understanding of the sources and their characteristics to aid in better pollution control. Owing to the geographical challenges of reducing air pollution in Chile, better air quality management tools are needed in the urban and industrial areas to further protect human health. While most of the studies in Chile have focused on PM10, further analysis should be done for PM2.5 and ultrafine particles, mainly chemical characterization, aerosols formation, better air pollution control technologies, and air quality and local climate change modeling. Chile recently released a new PM2.5 standard, which will take effect on January 1, 2012. As we look forward into the future, the importance of research cannot be neglected. There is a dire need for detailed ambient and source characterization through improved monitoring and modeling efforts thereby helping to meet the challenge. em References 1. Chile country profile; BBC News. See http://news.bbc.co.uk/2/hi/americas/country_profiles/1222764.stm (accessed May 2011). 2. Human and Income Poverty: Developing Countries; United Nations Development Programme. See http://hdrstats.undp.org/en/indicators/25.html (accessed May 2011). 3. IMACEC Marzo 2011; Chilean Central Bank: Santiago de Chile, 2011. 4. 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