Scholarlink

<p>COVID-19 restriction measures caused changes in air quality worldwide. This study intended to understand the variability in PM<sub>2.5</sub> and its chemical composition and identify its sources in an urban background station in the Aburrá Valley (Medellin Metropolitan Area), Colombia, during and after pandemic restrictions. The analysis was conducted from April 2019 to October 2022 to run PMF on a unique dataset, separating "a posteriori" source contributions for the 4 periods. The PM<sub>2.5</sub> composition was determined using different chemical analysis techniques and source apportionment was estimated by positive matrix factorization. The PM<sub>2.5</sub> mean concentration for the whole period was 18.8&#xa0;µg/m<sup>3</sup>. The most abundant species were organic carbon (OC) (32.9%), sulfate (8.4%), elemental carbon (EC) (4.1%), and nitrate (2.6%). The impact of the lockdown was assessed by comparing it with the pre-lockdown period (April 2019 to March 2020). Most species decreased, except for Be, Cu, Mo, F<sup>−</sup>, Cl<sup>−</sup> and the first OC fraction (OC1). Eight sources were identified: biomass burning, coal, diesel, industrial-dust mix, gasoline, incineration, vehicle non-exhaust (NE), and secondary sources. Long-range transport of biomass-burning smoke was a highly variable source, and it had a large contribution during the lockdown (54.1%) due to high fire activity in northern South America. The reduction in air pollution had remaining effects after the restrictions for PM<sub>2.5</sub> (28%), OC (29.2%), EC (16.4%), sulfates (24.7%), nitrates (42.6%), V (21.3%), Mn (26.0%) and Fe (34.8%).</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Effect of COVID-19 Pandemic Measures on PM2.5 and its Chemical Components in Aburrá Valley, Colombia 2019–2022

  • 期刊论文

  • 发表日期：

    2025年11月15日

查看全文
  • Miriam Gómez Marín,
  • Nestor Y. Rojas Roa,
  • A. Alba N. Ardila,
  • L. Kelly V. Patiño,
  • Maria P. Velásquez-García,
  • James A. Vergara-Correa

摘要

COVID-19 restriction measures caused changes in air quality worldwide. This study intended to understand the variability in PM2.5 and its chemical composition and identify its sources in an urban background station in the Aburrá Valley (Medellin Metropolitan Area), Colombia, during and after pandemic restrictions. The analysis was conducted from April 2019 to October 2022 to run PMF on a unique dataset, separating "a posteriori" source contributions for the 4 periods. The PM2.5 composition was determined using different chemical analysis techniques and source apportionment was estimated by positive matrix factorization. The PM2.5 mean concentration for the whole period was 18.8 µg/m3. The most abundant species were organic carbon (OC) (32.9%), sulfate (8.4%), elemental carbon (EC) (4.1%), and nitrate (2.6%). The impact of the lockdown was assessed by comparing it with the pre-lockdown period (April 2019 to March 2020). Most species decreased, except for Be, Cu, Mo, F−, Cl− and the first OC fraction (OC1). Eight sources were identified: biomass burning, coal, diesel, industrial-dust mix, gasoline, incineration, vehicle non-exhaust (NE), and secondary sources. Long-range transport of biomass-burning smoke was a highly variable source, and it had a large contribution during the lockdown (54.1%) due to high fire activity in northern South America. The reduction in air pollution had remaining effects after the restrictions for PM2.5 (28%), OC (29.2%), EC (16.4%), sulfates (24.7%), nitrates (42.6%), V (21.3%), Mn (26.0%) and Fe (34.8%).

Graphical Abstract