ABSTRACT

Objective

To assess the status of the legal framework for air quality control in all countries of Latin America and Caribbean (LAC); to determine the current distribution of air monitoring stations and mean levels of air pollutants in all capital and large cities (more than 100 000 inhabitants); and to discuss the implications for climate change and public policymaking.

Methods

From January 2015–February 2016, searches were conducted of online databases for legislation, regulations, policies, and air pollution programs, as well as for the distribution of monitoring stations and the mean annual levels of air pollution in all LAC countries.

Results

Only 117 cities distributed among 17 of 33 LAC countries had official information on ground level air pollutants, covering approximately 146 million inhabitants. The annual mean of inhalable particles concentration in most of the cities were over the World Health Organization Air Quality Guidelines; notably, only Bolivia, Peru, and Guatemala have actually adopted the guidelines. Most of the cities did not have information on particulate matter of 2.5 microns or less, and only a few measured black carbon.

Conclusions

The air quality regulatory framework should be updated to reflect current knowledge on health effects. Monitoring and control of ground level pollutants should be extended and strengthened to increase awareness and protect public health. Using the co-benefits of air pollution control for health and climate as a framework for policy and decision-making in LAC is recommended.

Keywords
Air pollution; climate change; environment and public health environmental policy; Latin America; South America; Caribbean Region

RESUMEN

Objetivo

Evaluar la situación del marco jurídico sobre el control de la calidad del aire en todos los países de América Latina y el Caribe; determinar la distribución actual de las estaciones de control del aire y la concentración media de los contaminantes atmosféricos de todas las capitales y ciudades grandes (de más de 100.000 habitantes); y analizar las implicaciones para el cambio climático y la formulación de políticas públicas.

Métodos

Se efectuaron búsquedas en bases de datos en línea entre enero del 2015 y febrero del 2016 con el fin de localizar leyes, reglamentos, políticas y programas de lucha contra la contaminación atmosférica, así como de determinar la distribución de las estaciones de control y la concentración media anual de contaminantes atmosféricos de todos los países de América Latina y el Caribe.

Resultados

Solo 77 ciudades ubicadas en 17 de 33 países de América Latina y el Caribe, lo que abarca a aproximadamente 146 millones de habitantes, disponían de información oficial sobre los contaminantes de la capa más baja de la atmósfera. En la mayoría de las ciudades, la concentración media anual de partículas inhalables supera los valores considerados aceptables en las directrices de la OMS sobre la calidad del aire; cabe destacar que, en realidad, solo Bolivia, Perú y Guatemala han adoptado estas directrices. La mayoría de las ciudades no tienen información sobre las PM_2,5 y solo algunas miden el hollín.

Conclusiones

Es preciso actualizar el marco jurídico sobre la calidad del aire incorporando los conocimientos actuales acerca de los efectos de la contaminación sobre la salud. Es necesario ampliar y fortalecer la vigilancia y el control de los contaminantes de la capa más baja de la atmósfera a fin de aumentar la concientización sobre este problema y proteger la salud pública. Se recomienda utilizar los beneficios colaterales para la salud y el clima que reporte el control de la contaminación atmosférica como marco para la formulación de políticas y la toma de decisiones en América Latina y el Caribe.

Palabras clave
Contaminación del aire; cambio climático; política de salud; medio ambiente y salud pública; América Latina; América del Sur; Región del Caribe

Air pollution is a key concern for the World Health Organization (WHO). At its 68th World Health Assembly, in May 2015, WHO adopted the resolution, “Addressing the Health Impacts of Air Pollution.” It recognized air pollution as a priority public health issue, one that is among the most important global environmental threats to health (¹1 World Health Organization. Health and the environment: addressing the health impact of air pollution. Geneva: WHO; 2015. [Report A68/18].). WHO estimates that each year 3.7 million people die from exposure to contaminated air in urban areas. Approximately 80% of these deaths are due to ischemic heart diseases and strokes; 14% to chronic obstructive pulmonary disease or acute lower respiratory infections; and 6% to lung cancer (²2 World Health Organiation. Burden of disease from ambient air pollution for 2012: description of method, source of the data and methods. Geneva: WHO; 2014. Available from: www.who.int/mediacentre/factsheets/fs313/en/ Accessed on 25 May 2016.
www.who.int/mediacentre/factsheets/fs313... ). The most health-relevant air pollutants are particulate matter (PM), especially PM with a diameter of 10 microns or less (PM₁₀; PM_2.5), which can penetrate and lodge deep inside the lungs. WHO estimates that approximately 58 000 deaths per year are attributable to ambient air pollution, and 80 000 to household air pollution in Latin America and the Caribbean (LAC) (²2 World Health Organiation. Burden of disease from ambient air pollution for 2012: description of method, source of the data and methods. Geneva: WHO; 2014. Available from: www.who.int/mediacentre/factsheets/fs313/en/ Accessed on 25 May 2016.
www.who.int/mediacentre/factsheets/fs313... ).

SHORT-LIVED CLIMATE POLLUTANTS AND THEIR PRECURSORS

Short-lived climate pollutants (SLCPs) are agents that reside in the atmosphere for a relatively short period and have a warming influence on climate. The main SLCPs are particles that contain black carbon (BC), tropospheric ozone (O₃), and methane (CH₄). These are the most important contributors to the global greenhouse effect after carbon dioxide (CO₂), and are substantial “climate forcers” (substances that significantly contribute to increased global temperature). CO₂ is responsible for much of the change experienced to date, and is expected to exert significant control of the warming rate during the next few decades (³3 United Nations Environment Program. Near-term climate protection and clean air benefits actions for controlling short-lived climate forcers: a UNEP synthesis report. Nai-robi: UNEP; 2011. Available from: www.unep.org/pdf/Near_Term_Climate_Protection_&_Air_Benefits.pdf Accessed on 25 May 2016.
www.unep.org/pdf/Near_Term_Climate_Prote... ). Hence, the implementation of measures to limit SCLPs is essential to slow the negative trends of climate change (⁴4 Bond TC, Doherty SJ, Fahey DW, Forster PM, Berntsen T, DeAngelo BJ, et al. Bounding the role of black carbon in the climate system: A scientific assessment. JGR. 2013;118:5380–552. – ⁶6 Molina M, Zaelke D, Sarma KM, Andersen SO, Ramanathan V, Kaniaru D. Reducing abrupt climate change risk using the Montreal Protocol and other regulatory actions to complement cuts in CO2 emissions. PNAS. 2009;106(49):20616–21.). The pollutants Nitrogen oxides (NOx), Sulfur dioxide (SO₂), BC, Organic Carbon (OC), as well as ammonia (NH₃), are important precursors to PM_2.5 and PM₁₀ (⁷7 United Nations Environment Programme, World Meteorological Organization. Integrated assessment of black carbon and tropospheric ozone. Nairobi: UNEP; 2011. Available from: www.unep.org/dewa/Portals/67/pdf/BlackCarbon_report.pdf Accessed on 24 May 2016.
www.unep.org/dewa/Portals/67/pdf/BlackCa... ).

A major fraction of PM_2.5 is constituted by BC, from 31% – 57% in urban areas (⁸8 Na K, Sawant AA, Song C, Cocker III DR. Primary and secondary carbonaceous species in the atmosphere of Western Riverside County, California. Atmos Environ. 2004;38(9):1345–55.–¹¹11 Martinez MA, Caballero P, Carrillo O, Mendoza A, Mejia GM. Chemical character-ization and factor analysis of PM2.5 in two sites of Monterrey, Mexico. J Air Waste Manag Assoc. 2012;62(7):817–27.). BC acts as a climate forcer by absorbing sunlight and darkening ice and snow, contributing to local and regional warming (¹²12 Anenberg SC, Schwartz J, Shindell D, Amann M, Faluvegi G, Klimont Z, et al. Global air quality and health co-benefits of mitigating near-term climate change through methane and black carbon emission controls. Environ Health Perspect. 2012;120(6):831–9.). BC can cause adverse health effects, such as asthma and other respiratory problems, low birth weights, heart attacks and other cardiovascular diseases, and lung cancer (¹³13 World Health Organization. Janssen N, Weltgesundheitsorganisation, eds. Health effects of black carbon. Copenhagen: WHO; 2012., ¹⁴14 Kulkarni N, Pierse N, Rushton L, Grigg J. Carbon in airway macrophages and lung function in children. N Engl J Med. 2006;355(1):21–30.). Anenberg and colleagues (¹⁵15 Anenberg SC, Horowitz LW, Tong DQ, West JJ. An estimate of the global burden of anthropogenic ozone and fine particulate matter on premature human mortality using atmospheric modeling. Environ Health Perspect. 2010;118(9):1189–95.) estimated that 3.7 million annual premature deaths are due to PM_2.5, and about 700 000, to O₃.

URBANIZATION TRENDS

Latin America and the Caribbean constitute a heterogeneous territory in terms of physical and human geography. The area covers about 200 million km². In 2013, its population reached 600 million inhabitants, with 79% living in urban centers (¹⁶16 United Nations, Department of Economic and Social Affairs. World Population Prospects: the 2012 Revision. Highlights and Advance Tables. New York: UN; 2013. [Report: ESA/P/WP.228].). LAC is the most urbanized geographic area in the developing world (2/3 of the population lives in cities of more than 20 000 inhabitants) (¹⁷17 Economic Commission for Latin America and the Caribbean. Statistical yearbook for Latin America and the Caribbean. Santiago, Chile: United Nations; 2014.). High urbanization trends, trade liberalization of goods and services, and the economic development experienced by LAC countries in recent decades has increased the demand for energy and transport. These are the main drivers of emissions in LAC (¹⁸18 Pan American Health Organization. Health in the Americas, 2012. Washington, DC: PAHO; 2012.).

AIR QUALITY MANAGEMENT IN LAC

There are previous reports on air quality in LAC (¹⁹19 Romieu I, Alamo-Hernández U, Texcalac-Sangrador JL, Pérez L, Gouveia N, McConnell R. La contaminación atmosférica en las Américas: tendencias, políticas y efectos. In: Determinantes ambientales y sociales de la salud. Washington, DC: Organizacion Panamericana de la Salud; 2010., ²⁰20 Clean Air Institute. La calidad del aire en América Latina: una visión panorámica. Washington DC: CAI; 2012. Available from: www.cleanairinstitute.org/calidaddelaireamericalatina/resumen-calidadaire-al.pdf Accessed on 10 May 2016.
www.cleanairinstitute.org/calidaddelaire... ), and a number of initiatives at the global level to leverage information on all aspects for air quality management (²¹21 World Health Organization. Global urban ambient air pollution database. Avail-able from: www.who.int/phe/health_topics/outdoorair/databases/cities/en/ Accessed on 27 May 2016.
www.who.int/phe/health_topics/outdoorair... , ²²22 United Nations Environment Program. UNEP Live. Available from: http://uneplive.unep.org Accessed on 2 June 2016.
http://uneplive.unep.org... ). However, a comprehensive analysis of the situation, with spatial visualization of the information including status of regulation, coverage and distribution of ground-level air monitoring stations, and ambient concentration of the main pollutants, by country, was missing.

The objective of this study was to fill this gap by presenting an overview of the status of air quality regulations in LAC. This overview comprises an assessment of the existing network of air quality monitoring stations, comparing to the area’s needs; and the current levels of the most important pollutants for air quality indicators, comparing to the WHO Air Quality Guidelines (WHO-AQG) (²³23 World Health Organization. Air quality guidelines. Global update 2005. Copenhagen: WHO; 2006.). Furthermore, findings are compared to the global agenda of the United Nations Convention on Climate Change (UNCCC), highlighting how reducing concentrations of short-lived climate pollutants can benefit both the climate and human health.

MATERIALS AND METHODS

Data collection

A search was conducted for the most recent year of data available on air quality policies and regulations for PM₁₀ and PM_2.5 in all 33 LAC countries. Data was gathered online from official national and international legal sources the WHO Global Health Observatory (WHO GHO), the United Nations Environmental Program (UNEP), the Economic Commission for Latin America and the Caribbean (ECLAC), the World Bank, and the Clean Air Institute (CAI), as well as local repositories of legal documents in LAC. PAHO Country Offices were informally consulted for verification. The most recent official population figures and urbanization trends available from international organizations, such as ECLAC and the United Nations, were used (¹⁷17 Economic Commission for Latin America and the Caribbean. Statistical yearbook for Latin America and the Caribbean. Santiago, Chile: United Nations; 2014., ²⁴24 Institute for Health Metrics and Evaluation. Global burden of disease 2015. Available from: www.healthdata.org/gbd2015 Accessed on 15 May 2016.
www.healthdata.org/gbd2015... , ²⁵25 United Nations Department of Economic and Social Affairs Population Division. World urbanization prospects: the 2014 revision: highlights. Available from: http://esa.un.org/unpd/wup/highlights/wup2014-highlights.pdf Accessed on 25 May 2016.
http://esa.un.org/unpd/wup/highlights/wu... ).

Air pollution legislation and regulations

Norms regulating air quality define the maximum allowed concentration of atmospheric contaminants during a specific period. Any reports available from international organizations were considered (¹⁹19 Romieu I, Alamo-Hernández U, Texcalac-Sangrador JL, Pérez L, Gouveia N, McConnell R. La contaminación atmosférica en las Américas: tendencias, políticas y efectos. In: Determinantes ambientales y sociales de la salud. Washington, DC: Organizacion Panamericana de la Salud; 2010., ²⁰20 Clean Air Institute. La calidad del aire en América Latina: una visión panorámica. Washington DC: CAI; 2012. Available from: www.cleanairinstitute.org/calidaddelaireamericalatina/resumen-calidadaire-al.pdf Accessed on 10 May 2016.
www.cleanairinstitute.org/calidaddelaire... ). National-level information was included for analysis. Data has been categorized and classified according to the permissible value limits for PM₁₀ and PM_2.5 in each country.

Air pollution measurements and average annual levels of pollutants

The data presented is based on a real-time air quality-monitoring network. Average annual levels of PM₁₀ and PM_2.5 provided directly by the country or by WHO Air Pollution database were used (²¹21 World Health Organization. Global urban ambient air pollution database. Avail-able from: www.who.int/phe/health_topics/outdoorair/databases/cities/en/ Accessed on 27 May 2016.
www.who.int/phe/health_topics/outdoorair... ). All the information was organized and systematized with Microsoft Excel™ (Microsoft Corporation, Redmond, Washington, United States).

Data visualization

Data was graphed and organized on thematic maps that summarize the information from countries and cities, including their national air quality standards, the distribution of air monitoring stations and networks, and average annual levels of PM₁₀ and PM_2.5. Cartographic information was managed in a Geographic Information System (GIS) through ArcGIS software, version 10.1 (Environmental Systems Research Institute, Redlands, California, United States). The geographic layers were obtained from Natural Earth (²⁶26 Natural Earth. Natural Earth data features. Available from: www.naturalearthdata.com/features/ Accessed on 1 November 2015.
www.naturalearthdata.com/features/... ).

All LAC cities with more than 100 000 inhabitants were mapped; however, if a country did not have a city of this size, its capital city was included. Each city’s average annual levels of PM₁₀ and PM_2.5 were compared to the WHO-AQG.

RESULTS

Urban population size

According to the United Nations (²⁷27 United Nations Statistical Office. Demographic yearbook 2014. Available from: http://unstats.un.org/unsd/demographic/products/dyb/dyb2.htm Accessed on 1 November 2015.
http://unstats.un.org/unsd/demographic/p... ) in 2014 there were approximately 564 cities with more than 100 000 inhabitants in LAC, with close to 286 million inhabitants in all. Among these, 58 cities had more than 500 000 inhabitants; 35 had more than 1 million; five cities had more than 5 million: Puebla (Mexico), Rio de Janeiro (Brazil), Santiago (Chile), Bogota (Colombia), and Lima (Peru); and three were classified as megacities with more than 10 million inhabitants: Buenos Aires (Argentina), Mexico City Metropolitan Area (Mexico), and São Paulo (Brazil). Figure 1 shows the distribution of cities with more than 100 000 inhabitants in LAC in 2014 (²⁷27 United Nations Statistical Office. Demographic yearbook 2014. Available from: http://unstats.un.org/unsd/demographic/products/dyb/dyb2.htm Accessed on 1 November 2015.
http://unstats.un.org/unsd/demographic/p... ).

Air quality monitoring networks

Only 17 of the 33 LAC countries had any information on ground level air quality measurements (Figure 2). However, most of these monitoring stations were only in each country’s capital city and a few major cities.The population living in cities with air monitoring networks was approximately 146 million people (20% of the total LAC population). Only 16 out of 58 cities with more than 500 000 inhabitants had undergone any measurement of air pollution in recent years.

In total, 17 LAC countries had official air quality monitoring stations: Argentina, Bolivia, Brazil, Chile, Colombia, Costa Rica, El Salvador, Ecuador, Guatemala, Jamaica, Mexico, Panama, Paraguay, Peru, Uruguay, Honduras, and Venezuela. PM₁₀ measurements were performed in 104 cities, and PM_2.5 in 57 cities.

The best monitoring systems for cities and population coverage were found in Brazil, Chile, Colombia, and Mexico. Brazil had networks of automatic monitoring stations in large cities, such as Belo Horizonte, Brasilia, Curitiba, Rio de Janeiro, and São Paulo. São Paulo State monitors the metropolitan area and 23 other cities in addition to its capital city, with a network of 49 automatic and 39 manual stations (²⁸28 Companhia Ambiental do Estado de São Paulo. Qualidade do ar no estado de São Paulo 2012. São Paulo: CETESB; 2013. Available from: http://ar.cetesb.sp.gov.br/publicacoes-relatorios/ Accessed on Aug 2016.
http://ar.cetesb.sp.gov.br/publicacoes-r... ). In addition, Rio de Janeiro State monitors its metropolitan area and all the high priority areas in 16 other cities identified by the State Environmental Agency using a network of 58 automatic and 60 semi-automatic monitoring stations (²⁹29 Instituto Estadual do Ambiente. Relatório da qualidade do ar do Estado do Rio de Janeiro. INEA, DIGAT, GRAR. Brazil; 2014. Available from: www.inea.rj.gov.br/cs/groups/public/@inter_dimfis_gear/documents/document/zwew/mte0/~edisp/inea0114522.pdf Accessed on Aug 2016.
www.inea.rj.gov.br/cs/groups/public/@int... ). High priority areas have more sources of emissions, as well as dense urban settlements.

Chile had a network of monitoring stations distributed throughout the country. Most were in the Metropolitan area of Santiago, and in larger cities on the Pacific coast, e.g., Arica, Tocopilla, Valparaiso, and Talcahuano.

Colombia had monitoring stations in Bogotá, Medellín, Cali, and Bucaramanga. Stations perform continuous measurements of PM, gaseous pollutants, and meteorological variables. The air quality-monitoring network in Bogotá consisted of 13 fixed monitoring stations and a mobile station, located across the city. In Medellín, there were 21 air quality monitoring stations; in Bucaramanga, 9; and in Santiago de Cali, 3.

Mexico had more than 80 sites with monitoring stations or networks where air quality was being measured regularly. However, in 2010, only 51 of them produced valid annual measurements of PM₁₀ or PM_2.5. Approximately 32 million people or 28% of the Mexican population (³⁰30 Texcalac Sangrador JL, Cervantes Martínez K, Riojas Rodríguez H, Hurtado Díaz M, Álamo Hernández U. Evaluación del impacto en salud por exposición a contaminan-tes atmosféricos criterio en 26 ciudades de México. Mexico City: Instituto Nacional de Salud Pública; 2014.) was living in the areas covered by these stations.

Bolivia had a network of air quality monitoring stations in La Paz, Santa Cruz, and Cochabamba. Ecuador had stations in Quito and Cuenca. All the other countries had some type of air quality data for their capital city only: Buenos Aires, Argentina; San José, Costa Rica; Santo Domingo, Dominican Republic; San Salvador, El Salvador; Guatemala City, Guatemala; Tegucigalpa, Honduras; Kingston, Jamaica; Panama City, Panama; Lima, Peru; Montevideo, Uruguay; and Caracas, Venezuela.

Air quality norms and regulations

The study found that the main pollutants regulated in LAC were PM₁₀, NO₂, and SO₂. PM₁₀ was being regulated in 19 countries; O₃, in 17 countries; NO₂, in 18 countries; and PM_2.5, in 13 countries.

WHO has set the AQG and three Interim Targets (IT) for PM₁₀ and PM_2.5 to help countries with high PM concentrations gradually improve air quality (²³23 World Health Organization. Air quality guidelines. Global update 2005. Copenhagen: WHO; 2006.). The acceptable limits for these pollutants in each LAC country’s regulations is compared to the WHO-AQG in Table 1. National standards for air contaminants varied among countries, but in most of them, the standards were well above the WHO-AQG. Only Bolivia, Guatemala, and Peru had adopted the WHO-AQG for PM_10, and only Guatemala, for PM_2.5.

The study did not find any air pollution regulations in 10 countries: Antigua and Barbuda, Bahamas, Barbados, Dominica, Grenada, Haiti, Saint Lucia, St. Kitts and Nevis, St. Vincent and the Grenadines, and Suriname.

Current concentrations of air pollutants

Average annual data from the 104 cities that monitor PM₁₀ showed that only Salvador de Bahia (Brazil) was within the WHO 20 µg/m³ guideline. Of the others, 9 cities had concentrations that exceeded the IT-1 (70 µg/m3), but 20 were within it; 46 were within IT-2 (50 µg/m³); and 24 were within IT-3 (30 µg/m³). For the 57 cities that monitor PM_2.5, the annual average data showed that 4 cities met the WHO 10 µg/m³ guidelines. PM_2.5 average levels for 12 cities were within the IT-1 of 35 µg/m³; 25 cities were within IT-2 (25 µg/m³), 9 cities were within IT-3 (15 µg/m³). Seven cities had concentrations that exceeded WHO IT-1. Figure 3 shows PM₁₀ and PM_2.5 in some LAC cities.

The study did not find any information on air quality for the following countries: Antigua and Barbuda, Bahamas, Barbados, Belize, Cuba, Dominica, Dominican Republic, El Salvador, Grenada, Guyana, Haiti, Nicaragua, Panama, Paraguay, Saint Lucia, St. Kitts and Nevis, St. Vincent and the Grenadines, Suriname, and Trinidad and Tobago.

Short-lived climate pollutants

Almost 12% of the world’s BC emissions are from LAC (³¹31 Gladstein, Neandross & Associates. Dumping dirty diesels in Latin America: reducing black carbon and air pollution from diesel engines in Latin American countries. Natural Resources Defense Council; 2014.). However, most LAC countries do not monitor BC directly. Lima was the first city to monitor BC emissions (³¹31 Gladstein, Neandross & Associates. Dumping dirty diesels in Latin America: reducing black carbon and air pollution from diesel engines in Latin American countries. Natural Resources Defense Council; 2014.). Studies on BC concentration are scarce, but some have been performed in Mexico. The Mexico City Metropolitan Area is the largest source of SCLPs in Latin America.

The composition of PM is complex and varies according to sources, time, and place. Retama and colleagues (³²32 Retama A, Baumgardner D, Raga GB, McMeeking GR, Walker JW. Seasonal and diurnal trends in black carbon properties and co-pollutants in Mexico City. Atmospheric Chem Phys. 2015;15(16):9693–709.) derived the extended measurements of equivalent black carbon (eBC) from light absorption measurements and found that the cross-correlation between the eBC and PM_2.5 presents a complex relationship between BC (produced by primary emissions and particle mass that is a mixture of primary and secondary processes). Although the eBC was approximately 20% of the mass of PM_2.5 in their study, the maximum concentration changes differ from the rainy to the dry seasons, being eBC 8.8 – 13.1 µg m^-3 (44 %) and for PM_2.5, 49 – 73 µg m^-3 (61 %). Takahama and colleagues (³³33 Takahama S, Russell LM, Shores CA, Marr LC, Zheng J, Levy M, et al. Diesel vehicle and urban burning contributions to black carbon concentrations and size distributions in Tijuana, Mexico, during the Cal-Mex 2010 campaign. Atmos Environ. 2014;88:341–52.) characterized BC during 2010 by three complementary techniques: incandescence, light absorption, and volatility. They found three different-sized modes of BC mass in particles; the mode from 200–300 nm was associated with urban burning activities.

In 2006, as part of the Megacities Initiative in Mexico City, BC was measured at two-minute intervals using an aethalo-meter at 880 nm. The researchers found that Mexico City’s PAH-to-BC mass ratio of 0.01 was similar to that found on a freeway loop in Los Angeles (United States), approximately 8 – 30 times higher than in other cities (³⁴34 Thornhill DA, de Foy B, Herndon SC, Onasch TB, Wood EC, Zavala M, et al. Spatial and temporal variability of particulate polycyclic aromatic hydrocarbons in Mexi-co City. Atmos Chem Phys. 2008;8(12):3093–105.). In addition, the emission factor of BC from diesel vehicles in Mexico City was found to be over 6 times higher than that of Zurich (Switzerland), and about 1.5 times higher than that of Oakland, California (United States) (³⁵35 United States Agency for International Development. Urbanization in Latin Amer-ica and the Caribbean: trends and challenges. Washington, DC: USAID; 2010.).

The United Nations Environmental Program (UNEP) has indicated that implementing specific measures targeting significant sources of BC and CH₄ would avoid about 2.4 million premature deaths globally, and halve the rate of warming over the next decades (³3 United Nations Environment Program. Near-term climate protection and clean air benefits actions for controlling short-lived climate forcers: a UNEP synthesis report. Nai-robi: UNEP; 2011. Available from: www.unep.org/pdf/Near_Term_Climate_Protection_&_Air_Benefits.pdf Accessed on 25 May 2016.
www.unep.org/pdf/Near_Term_Climate_Prote... ). According to the global-scale UNEP/World Meteorological Organization (⁷7 United Nations Environment Programme, World Meteorological Organization. Integrated assessment of black carbon and tropospheric ozone. Nairobi: UNEP; 2011. Available from: www.unep.org/dewa/Portals/67/pdf/BlackCarbon_report.pdf Accessed on 24 May 2016.
www.unep.org/dewa/Portals/67/pdf/BlackCa... ) assessment, this could reduce BC by close to 300 000 tons. Ozone (O₃) is also a SLCP, and the Global Burden of Disease Study estimates that in 2010, almost 22 079 disability-adjusted life years in LAC were attributable to O₃ exposure (²⁴24 Institute for Health Metrics and Evaluation. Global burden of disease 2015. Available from: www.healthdata.org/gbd2015 Accessed on 15 May 2016.
www.healthdata.org/gbd2015... ).

DISCUSSION

The normative framework and air quality monitoring are important components of air quality management. Thus, we presented here an overview of the status of air quality management in LAC, including regulations and monitoring, and the situation in public health terms. PAHO had reported decreasing annual means of PM₁₀ in some countries in 2006 – 2010 (¹⁸18 Pan American Health Organization. Health in the Americas, 2012. Washington, DC: PAHO; 2012.). The Clean Air Institute had published a useful review of this topic in 2012 (²⁰20 Clean Air Institute. La calidad del aire en América Latina: una visión panorámica. Washington DC: CAI; 2012. Available from: www.cleanairinstitute.org/calidaddelaireamericalatina/resumen-calidadaire-al.pdf Accessed on 10 May 2016.
www.cleanairinstitute.org/calidaddelaire... ), presenting annual average PM₁₀ for 16 cities in LAC and PM_2.5 for 11 cities. Only one of these cities complied with the WHO-AQG (²⁰20 Clean Air Institute. La calidad del aire en América Latina: una visión panorámica. Washington DC: CAI; 2012. Available from: www.cleanairinstitute.org/calidaddelaireamericalatina/resumen-calidadaire-al.pdf Accessed on 10 May 2016.
www.cleanairinstitute.org/calidaddelaire... ). Likewise, the present overview of 104 cities for PM₁₀ and 57 cities for PM_2.5 found that five cities complied with the WHO-AQG for the annual mean of PM₁₀, and four complied for PM_2.5.

The interim targets proposed by WHO are steps toward progressive reduction of air pollution (³⁶36 United Nations Framework Convention on Climate Change. Adoption of the Paris Agreement. Paris: UNFCCC; 2016. Available from: http://unfccc.int/paris_agreement/items/9485.php Accessed May 2016.
http://unfccc.int/paris_agreement/items/... ).Therefore, when formulating policy targets, governments should consider the local context carefully before adopting the guidelines directly as legally based standards. In addition, governments should indicate how and when the standards are to be achieved. Since the epidemiological evidence indicates that the possibility of adverse health effects remains even if the guideline value is achieved, some countries might chose to adopt guidelines for lower concentrations than the WHO-AQG values (³¹31 Gladstein, Neandross & Associates. Dumping dirty diesels in Latin America: reducing black carbon and air pollution from diesel engines in Latin American countries. Natural Resources Defense Council; 2014.). It is important for all the countries to have an updated regulatory framework for all the pollutants, especially for PM_2.5.

The urbanization process continues to increase in LAC (²⁴24 Institute for Health Metrics and Evaluation. Global burden of disease 2015. Available from: www.healthdata.org/gbd2015 Accessed on 15 May 2016.
www.healthdata.org/gbd2015... , ³⁷37 Riojas-Rodríguez H, Álamo-Hernández U, Texcalac-Sangrador JL, Romieu I. Health impact assessment of decreases in PM10 and ozone concentrations in the Mexico City Metropolitan Area: A basis for a new air quality management program. Salud Pública México. 2014;56(6):579–91.). Similarly, there are trends of increased motorization of the urban population, which may predict future rising levels of pollutants in cities (²⁴24 Institute for Health Metrics and Evaluation. Global burden of disease 2015. Available from: www.healthdata.org/gbd2015 Accessed on 15 May 2016.
www.healthdata.org/gbd2015... , ³⁵35 United States Agency for International Development. Urbanization in Latin Amer-ica and the Caribbean: trends and challenges. Washington, DC: USAID; 2010.). Household combustion of solid fuels for cooking or heating could also contribute to the overall urban air pollution in countries where considerable fraction of the population uses solid fuels as their main source of energy. All these trends, associated with the predicted effects of climate change (³⁸38 World Health Organization. Health risk assessment of air pollution: General principles. Copenhagen: WHO; 2016.), are driving forces of air pollution in LAC. To prevent raising the burden of diseases attributed to air pollution, it is necessary to promote concerted action by all sectors, particularly those related to urban planning. This includes sustainable solutions for public transportation and mobility, and sustainable clean energy solutions for all. Air pollution control to protect public health and the environment are urgent and imperative.

The methodology of Health Impact Assessment (HIA) used and validated in several countries is a handy tool that could be used to assess the cost-benefits of different types of policy interventions that tackle air pollution (²⁶26 Natural Earth. Natural Earth data features. Available from: www.naturalearthdata.com/features/ Accessed on 1 November 2015.
www.naturalearthdata.com/features/... , ³⁷37 Riojas-Rodríguez H, Álamo-Hernández U, Texcalac-Sangrador JL, Romieu I. Health impact assessment of decreases in PM10 and ozone concentrations in the Mexico City Metropolitan Area: A basis for a new air quality management program. Salud Pública México. 2014;56(6):579–91., ³⁸38 World Health Organization. Health risk assessment of air pollution: General principles. Copenhagen: WHO; 2016.). A HIA study in Mexico estimated that the application of new PM_2.5 standards could prevent approximately 6 669 deaths each year in 12 Mexican cities (³⁰30 Texcalac Sangrador JL, Cervantes Martínez K, Riojas Rodríguez H, Hurtado Díaz M, Álamo Hernández U. Evaluación del impacto en salud por exposición a contaminan-tes atmosféricos criterio en 26 ciudades de México. Mexico City: Instituto Nacional de Salud Pública; 2014.). Also, HIA can estimate the burden of air pollution on sub-population groups, quantifying the contribution of air pollution to health inequities. Furthermore, HIA results can be useful for supporting stakeholder’s negotiations when updating the regulatory framework at the national level.

Updating standards does not improve air quality, but is important for influencing programs such as emissions control. Multisectoral action is required to change processes and accelerate the adoption of cleaner energy. Each update in the regulations should be coupled with agreements with polluters on rigorous implementation plans and realistic deadlines.

It is important to measure the average annual concentration of fine particles because of their associated chronic health effects and to better estimate the burden of diseases attributable to air pollution. Satellite models help build average estimations of exposure, but are more reliable in larger areas with ground level measurements. However, differential population risks and vulnerabilities in small areas imply that areas with high air pollution should be identified.

Coverage of monitoring networks is clearly insufficient, reaching only 146 million people, less than one-third of the urban population of LAC. There is a need to invest in monitoring networks, as measuring air pollution raises awareness and gives guidance to evidence-based effective interventions. It is also necessary to evaluate progress toward meeting the WHO-AQG and for accountability reports of the control policies implemented.

BC is a component of PM_2.5 and could be measured separately without great technical challenges. Understanding its distribution according to different sources and estimating its effect on climate and health in LAC are necessary. There is now an opportunity to boost PM_2.5 control as part of the mitigation of climate change, so that the corresponding co-benefits of emission control strategies can be generated and estimated.

The WHO and the UNEP resolutions on air pollution (³⁹39 World Health Organization. Sixty-eighth World Health Assembly. Available from: www.who.int/mediacentre/events/2015/wha68/en/ Accessed on 1 February 2016.
www.who.int/mediacentre/events/2015/wha6... , ⁴⁰40 United Nations Environment Program. Historic UN Environment Assembly calls for strengthened action on air quality, linked to 7 million deaths annually, among 16 major resolutions; 2014. Available from: www.unep.org/newscentre/Default.aspx?DocumentID=2791&ArticleID=10931 Accessed on 1 February 2016.
www.unep.org/newscentre/Default.aspx?Doc... ), as well as the Plan of Action on Air Pollution adopted by the XIX Meeting of the Forum of Ministers of Environment of Latin America and the Caribbean (⁴¹41 Foro de Ministros de Medio Ambiente de América Latina y el Caribe. Declaración de Los Cabos. Proceedings of the XIX Reunión del Foro de Ministros de Medio Ambiente de América Latina y el Caribe; 2014. Available from: www.pnuma.org/forodeministros/19-mexico/documentos/Declaracion/Declaracion_Ministerial.pdf Accessed on 1 February 2016.
www.pnuma.org/forodeministros/19-mexico/... ) can guide the development of national air quality action plans, taking into consideration the unique circumstances of each country.

LIMITATIONS

This study has some limitations. Some of the data may be incomplete, as there might be information that was not available in any of the sources. Furthermore, legal frameworks, particularly those regarding regulatory matters, may have changed after the information was collected. Additionally, many of the impacts of short-lived pollutants on the climate of Latin America and the Caribbean are not well understood or quantified. Local studies on their concentration and health effects are needed.

CONCLUSIONS

Scientific evidence indicates that fast and widespread action to reduce the SCLPs has the potential to significantly slow the rate of global warming, offering one of the few pathways to achieving near-term climate impacts (⁹9 Russell M, Allen DT. Seasonal and spatial trends in primary and secondary organic carbon concentrations in southeast Texas. Atmos Environ. 2004;38(20):3225–39.). The annual mean values of PM₁₀ and PM_2.5 in most measured sites in LAC are significantly higher than the WHO-AQG. In addition, countries have been slow to incorporate the WHO-AQG guidelines into national level regulations and in establishing networks for air quality monitoring. However, there is increased awareness of the problem and resolutions by the United Nations Environment Assembly (⁴⁰40 United Nations Environment Program. Historic UN Environment Assembly calls for strengthened action on air quality, linked to 7 million deaths annually, among 16 major resolutions; 2014. Available from: www.unep.org/newscentre/Default.aspx?DocumentID=2791&ArticleID=10931 Accessed on 1 February 2016.
www.unep.org/newscentre/Default.aspx?Doc... ) and by the World Health Assembly (³⁹39 World Health Organization. Sixty-eighth World Health Assembly. Available from: www.who.int/mediacentre/events/2015/wha68/en/ Accessed on 1 February 2016.
www.who.int/mediacentre/events/2015/wha6... ) calling for action on air pollution.

Air pollution, especially SLCPs, impose a heavy cost in terms of ill health and premature deaths in LAC. More knowledge of their sources, atmospheric transfer, impacts, and effectiveness of remedial measures is need. Another key priority is raising awareness of the direct and indirect health effects of SCLPs among both decisionmakers and the general population.

Air quality monitoring sites are limited in LAC. Investments should be made to strengthen and improve the existing monitoring networks, and at a minimum, extend coverage to all cities with more than 500 000 inhabitants. In particular, whenever possible, PM_2.5 and BC should be measured.

It is imperative to strengthen air quality management in LAC and to implement the WHO-AQG in the medium- to long-term. An intersectoral air quality management program that is sensitive to the participation of organized communities and different interest groups could help policy and decisionmakers focus on obtaining the best, most sustainable benefit for health, equity, and the climate when considering policy options.

Furthermore, it is necessary to generate information on air quality and estimates of the burden of disease attributable to air pollution at the country level. This information will facilitate risk communication and provide reliable data for future estimations of the economic and social costs and benefits associated with the different policy options. Implementation of the Climate Change Paris Agreement (³³33 Takahama S, Russell LM, Shores CA, Marr LC, Zheng J, Levy M, et al. Diesel vehicle and urban burning contributions to black carbon concentrations and size distributions in Tijuana, Mexico, during the Cal-Mex 2010 campaign. Atmos Environ. 2014;88:341–52.) is a challenge, but represents a great opportunity to build and strengthen air quality management in LAC, optimizing the immediate benefits for both climate and public health, especially at the local level. Therefore, bolstering the capacity of the health sector to better respond to and take advantage of these challenges and opportunities is essential.

Acknowledgements

The authors thank Sara Jane Velázquez Juárez for her assistance in the preparation of the maps and figures.

Conflict of interests

None declared.

Disclaimer

Authors hold sole responsibility for the views expressed in the manuscript, which may not necessarily reflect the opinion or policy of the RPSP/PAJPH and/or PAHO.

REFERENCES

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