Spatiotemporal Variations and Contributing Factors of Air Pollutants in Almaty, Kazakhstan
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Aerosol and Air Quality Research, 20: 1340–1352, 2020 Publisher: Taiwan Association for Aerosol Research ISSN: 1680-8584 print / 2071-1409 online https://doi.org/10.4209/aaqr.2019.09.0464 Spatiotemporal Variations and Contributing Factors of Air Pollutants in Almaty, Kazakhstan Aiymgul Kerimray1*, Eldar Azbanbayev2, Bulat Kenessov1, Pavel Plotitsyn3, Danara Alimbayeva4, Ferhat Karaca5,6 1 Center of Physical-Chemical Methods of Research and Analysis, Faculty of Chemistry and Chemical Technology, Al Farabi Kazakh National University, Almaty, Kazakhstan 2 Department of Mechanical and Aerospace Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur-Sultan, Kazakhstan 3 Airkaz.org, Almaty, Kazakhstan 4 National Hydrometeorological Service of Kazakhstan, Nur-Sultan, Kazakhstan 5 Department of Civil and Environmental Engineering, Nazarbayev University, Nur-Sultan, Kazakhstan 6 The Environment & Resource Efficiency Cluster, Nazarbayev University, Nur-Sultan, Kazakhstan ABSTRACT In this study, spatial and temporal patterns of PM10, PM2.5, NO2, SO2, and CO in Almaty, the largest city of Kazakhstan, in the period between 2013 and 2018 are explored. Severe degradation of air quality was observed from the data that were used in this study. Annual averages of PM2.5, PM10, and NO2 concentrations exceeded the WHO annual limits by 5.3, 3.9, and 3.2 times, respectively. The maximum levels were observed in the winter, while the minimum levels in the summer. Winter-to-summer difference was more noticeable for PM2.5 than for other pollutants. The winter pollution peaks demonstrate the high contribution of large- and small-scale coal combustion for heating, which could be exacerbated with lower winds and possible more frequent thermal inversions. There was a negative correlation between elevation and levels of SO2, PM2.5, and PM10, while no correlation was observed for NO2 and CO, indicating that the former group could be mainly contributed by point sources located predominantly at lower elevations (e.g., power plants) and the latter group mainly originated from nonpoint sources distributed evenly across the city (e.g., transport). Urgent measures are needed to reduce emissions from the coal-fired power plant and from the domestic heating stoves. Keywords: Aerosol; Air quality; Atmospheric air pollution; Particulate matter; Kazakhstan; Almaty. INTRODUCTION demand (World Bank, 2017). Almaty was initially designed for less than a million dwellers (in 1990) (Nazhmetdinova et Rapid economic development, exploitation of natural al., 2018); however, its population has reached 1.85 million resources, lax environmental regulations, and weak due to massive migration waves (Committee of Statistics of enforcement have led to environmental degradation in many the Ministry of the National Economy of the Republic of locations in Kazakhstan (Russel et al., 2018). Almaty, the Kazakhstan, 2019a). former capital and the largest urban center in Kazakhstan, is Currently, the city is heavily dependent on the use of coal: one of the most polluted cities in Kazakhstan (Russel et al., 2.6 million tons of coal in total were used in 2015 (World 2018; Kerimray et al., 2019), and one of the air pollution Bank, 2017). For the city of Almaty with its surrounding “hotspots” in the country, particularly with NO2 (Darynova region, 64% of the electric energy supply originates from et al., 2018). Almaty experienced a constant population and local power plants, and the remaining 36% are purchased economic growth, which has inevitably resulted (and may from Pavlodar region (ALES, 2019). The сoal-fired combined continue to result in the future) in an increased number of heat and power plant named “CHP-2”, the largest power transportation activities, urbanization, and increased energy plant, located in the north-west of the city is equipped with an emulsifier for cleaning flue gases from ash and dust (ALES, 2019). The effectiveness of SO2, NO2, PM10, and PM2.5 removal at the CHP-2 are not reported. In Kazakhstan, * Corresponding author. emissions from coal-fired power plants are substantially Tel.: +7701 908 97 37 higher than the limit values for power plants in Europe: E-mail address: [email protected] 10 times for PM, by 20% for NOx and 2.5 times for SOx Copyright The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are cited. Kerimray et al., Aerosol and Air Quality Research, 20: 1340–1352, 2020 1341 (Concept on the Transition of the Republic of Kazakhstan to studies in Almaty focused on transportation-related emissions the "Green Economy", 2013). (Carlsen et al., 2013); benzene, toluene, ethylbenzene, and Given that the maximum concentrations of PM10, NO2, xylenes (BTEX) concentrations and ratios (Baimatova et al., and SO2 occur during wintertime, large- and small-scale heat 2016); CO, TSP and lead concentrations and compliance production is a significant source of pollution (World Bank, with sanitary standards (Nazhmetdinova et al., 2018); and 2013; Darynova et al., 2018). Residential and commercial aerosol variations and sources using Aqua-MODIS Collection buildings without access to district heating rely on coal or 6.1 data (Rupakheti et al., 2019). World Health Organisation gas, which are often burned in inefficient stoves (Kerimray (WHO) Global Ambient Air Quality Database (WHO, 2018) et al., 2018). Due to the cold climate and poor dispersion does not contain data on PM10 and PM2.5 concentrations in conditions, small-scale combustion can also contribute to Kazakhstan cities, and the recent report of United Nations episodic air pollution events in the wintertime (World Bank, Environment Program (UNEP) on air quality in Asia did 2013). also not include Kazakhstan (United Nations Environment Elevated concentrations of NO2 and CO in Almaty can Program, 2019). Thus, there is a clear gap in the knowledge also indicate the contribution of the urban transport sector of air quality levels in Kazakhstan in international databases (World Bank, 2013). Most passenger cars (63%) do not and studies. satisfy the requirements of the Euro 4 emission standard National Hydrometeorological Service of Kazakhstan (UNDP, 2017), and 75% of the cars are older than 7 years “Kazhydromet” owns and operates the National Air Quality (Municipality of Almaty City, 2018). Quality of oil products Monitoring Network (NAQMN) for many pollutants (total is also an issue with frequent cases of noncompliance with suspended particles - TSP, NO2, SO2, CO, etc.) in the cities fuel quality standards and the late introduction of fuel quality of Kazakhstan (and some villages). The number of standards (Euro 3 and Euro 4) in 2018 (Kazenergy, 2017). measurement locations of PM2.5 and PM10 has gradually The number of registered light-duty vehicles has increased increased since 2016. In 2017, an independent PM2.5 by 6% annually over 2003–2018 reaching 471 thousand measurement network (Airkaz) was established with a vehicles (Committee of Statistics of the Ministry of the higher number of measurement stations than the NAQMN National Economy of the Republic of Kazakhstan, 2019b), in the three largest cities of Kazakhstan. The real-time PM2.5 without accounting for unregistered vehicles entering and measurements are displayed at the Airkaz.org website. leaving the city on a daily basis from suburban areas. Despite the deteriorating situation, there is a lack of Natural sources such as windblown dust are likely to have studies exploring spatial-temporal variations of air pollutants low contributions to the deterioration of the air quality in and the impact of meteorology on air quality in the city. Almaty as dust and sand storms are more frequent in other Studies on air quality are urgently needed because of the locations, particularly in the southern desert zone of high public exposure to dangerous pollution levels, complex Kazakhstan (Issanova and Abuduwaili, 2017). and unique topographic, and meteorological conditions. Exposure to ambient air pollution increases the mortality Similar studies have been conducted in other places where and morbidity as a result of increased risk of ischemic heart significant spatial and temporal variations of particulate disease, cerebrovascular disease, lung cancer, chronic matter and gaseous pollutants were detected using data from obstructive pulmonary disease and lower respiratory infections air quality measurements, and possible reasons for such (Cohen et al., 2017). The epidemiological studies suggest that variations were discussed (Alizadeh-Choobari et al., 2016). the prevalence of bronchial asthma and chronic obstructive In this work, spatial and temporal patterns of air quality pulmonary disease (COPD) in Almaty is high. The prevalence in Almaty were studied based on the data from the NAQMN of "wheezing symptoms" was 74.4, 254.8, and 123.4 per (TSP, NO2, SO2, CO) and Airkaz (PM2.5) during the years of 1000 people in Kyiv (Ukraine), Almaty (Kazakhstan), and 2013–2018. The effects of meteorological parameters on the Baku (Azerbaijan), respectively (Nugmanova et al., 2018a). pollutants were investigated. The spatiotemporal variation Thus, in Almaty, it was 3.4 and 2.1 times higher than in Kyiv of air pollution and its relationships with distance to coal- and Baku, respectively. The prevalence of chronic obstructive fired power plants and elevation above sea