Assessing air quality changes in large cities during COVID-19 lockdowns: The impacts of traffic-free urban conditions in Almaty, Kazakhstan

doi:10.1016/j.scitotenv.2020.139179

	Assessing air quality changes in large cities during COVID-19 lockdowns: The impacts of traffic-free urban conditions in Almaty, Kazakhstan
	Kerimray, Aiymgul 1; Baimatova, Nassiba 1; Ibragimova, Olga P.1; Bukenov, Bauyrzhan 1; Kenessov, Bulat 1; Plotitsyn, Pavel 2; Karaca, Ferhat 3
	2020-08
发表期刊	SCIENCE OF THE TOTAL ENVIRONMENT
ISSN	0048-9697
EISSN	1879-1026
摘要	Number of cities worlwide experienced air quality improvements during COVID-19 lockdowns; however, such changes may have been different in places with major contributions from nontraffic related sources. In Almaty, a city-scale quarantine came into force on March 19, 2020, which was a week after the first COVID-19 case was registered in Kazakhstan. This study aims to analyze the effect of the lockdown from March 19 to April 14, 2020 (27 days), on the concentrations of air pollutants in Almaty. Daily concentrations of PM2.5, NO2, SO2, CO, O-3, and BTEX were compared between the periods before and during the lockdown. During the lockdown, the PM2.5 concentration was reduced by 21% with spatial variations of 6-34% compared to the average on the same days in 2018-2019, and still, it exceeded WHO daily limit values for 18 days. There were also substantial reductions in CO and NO2 concentrations by 49% and 35%, respectively, but an increase in O-3 levels by 15% compared to the prior 17 days before the lockdown. The concentrations of benzene and toluene were 2-3 times higher than those during in the same seasons of 2015-2019. The temporal reductions may not be directly attributed to the lockdown due to favorable meteorological variations during the period, but the spatial effects of the quarantine on the pollution levels are evidenced. The results demonstrate the impact of traffic on the complex nature of air pollution in Almaty, which is substantially contributed by various nontraffic related sources, mainly coal-fired combined heat and power plants and household heating systems, as well as possible small irregular sources such as garbage burning and bathhouses. (C) 2020 Elsevier B.V. All rights reserved.
关键词	Air quality Pollution Almaty SARS-CoV-2 Lockdown
DOI	10.1016/j.scitotenv.2020.139179
WOS关键词	AROMATIC-HYDROCARBONS ; BTEX ; POLLUTION
WOS研究方向	Environmental Sciences & Ecology
WOS类目	Environmental Sciences
出版者	ELSEVIER
引用统计
文献类型	期刊论文
专题	新冠肺炎循证社会科学证据集成
作者单位	1.Al Farabi Kazakh Natl Univ; 2.Airkaz Org; 3.Nazarbayev Univ
推荐引用方式 GB/T 7714	Kerimray, Aiymgul,Baimatova, Nassiba,Ibragimova, Olga P.,et al. Assessing air quality changes in large cities during COVID-19 lockdowns: The impacts of traffic-free urban conditions in Almaty, Kazakhstan[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2020.
APA	Kerimray, Aiymgul.,Baimatova, Nassiba.,Ibragimova, Olga P..,Bukenov, Bauyrzhan.,Kenessov, Bulat.,...&Karaca, Ferhat.(2020).Assessing air quality changes in large cities during COVID-19 lockdowns: The impacts of traffic-free urban conditions in Almaty, Kazakhstan.SCIENCE OF THE TOTAL ENVIRONMENT.
MLA	Kerimray, Aiymgul,et al."Assessing air quality changes in large cities during COVID-19 lockdowns: The impacts of traffic-free urban conditions in Almaty, Kazakhstan".SCIENCE OF THE TOTAL ENVIRONMENT (2020).