Water-soluble inorganic ions (WSIs) in the aerosols from Central Asia via transboundary transport measured in Jimunai in 2020

Environ Sci Pollut Res Int. 2023 Sep;30(43):97040-97051. doi: 10.1007/s11356-023-29083-7. Epub 2023 Aug 16.

Abstract

Air pollution is a global issue that often transcends national borders, leading to disputes over environmental concerns and climate-mitigation responsibilities. Between March and July 2020, we collected aerosol samples in Jimunai, a town in western China neighboring Kazakhstan, to assess transboundary air pollution in the region. Our analysis focused on major water-soluble inorganic ions (WSIs), with Ca2+ and SO42- accounting for almost 60% of the total ion loading. The ratio of cations to anions was greater than one (1.33 ± 0.27), indicating alkaline aerosols during the sampling period. Our results suggest that the pollutants measured were primarily sourced from Kazakhstan, as demonstrated by local meteorological data, air-mass trajectory analysis, and pollutant emission inventories in Kazakhstan. Correlation and primary component analysis indicated that NH4+ played an important role in neutralizing NO3- and SO42-, while Cl- was significantly depleted by the probable reaction HNO3↑ + NaCl = HCl↑ + NaNO3. These findings highlight the need for continued monitoring and regulation of air pollution sources in the region to address transboundary air pollution.

Keywords: HYSPLIT; Jimunai; Kazakhstan; Transboundary pollution; Water-soluble inorganic ions (WSIs).

MeSH terms

  • Aerosols / analysis
  • Air Pollutants* / analysis
  • Cations / analysis
  • China
  • Environmental Monitoring
  • Environmental Pollutants* / analysis
  • Ions / analysis
  • Particle Size
  • Particulate Matter / analysis
  • Seasons
  • Water / analysis

Substances

  • Water
  • Particulate Matter
  • Air Pollutants
  • Ions
  • Cations
  • Aerosols
  • Environmental Pollutants