Annual Variation of PM2.5 Chemical Composition in Ho Chi Minh City, Vietnam Including the COVID-19 Outbreak Period

Abstract PM2.5 was continuously collected in Ho Chi Minh City (HCMC), Vietnam, during the period from September 2019 to August 2020, which included the period of socioeconomic suppression caused by restrictions imposed in the face of the coronavirus disease of 2019. The concentrations of PM2.5 mass,...

Full description

Saved in:
Bibliographic Details
Main Authors: Ngoc Tran, Yusuke Fujii, Vinh Xuan Le, Nguyen Doan Thien Chi, Hiroshi Okochi, To Thi Hien, Norimichi Takenaka
Format: Article
Language:English
Published: Springer 2023-03-01
Series:Aerosol and Air Quality Research
Subjects:
Online Access:https://doi.org/10.4209/aaqr.220312
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract PM2.5 was continuously collected in Ho Chi Minh City (HCMC), Vietnam, during the period from September 2019 to August 2020, which included the period of socioeconomic suppression caused by restrictions imposed in the face of the coronavirus disease of 2019. The concentrations of PM2.5 mass, water-soluble ions (WSIs), organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were determined to evaluate the seasonal variations in PM2.5, the effect of socioeconomic suppression on PM2.5, and potential PM2.5 sources in HCMC. The PM2.5 mass concentration during the sampling period was 28.44 ± 11.55 µg m−3 (average ± standard deviation). OC, EC, and total WSIs accounted for 30.7 ± 6.6%, 9.7 ± 2.9%, and 24.9 ± 6.6% of the PM2.5 mass, respectively. WSOC contributed 46.4 ± 10.1% to OC mass. NO3−, SO42−, and NH4+ were the dominant species in WSIs (72.7 ± 17.7% of the total WSIs’ mass). The concentrations of PM2.5 mass and total WSIs during the rainy season were lower than those during the dry season, whereas the concentrations of carbonaceous species during the rainy season were higher. The concentrations of PM2.5 mass and chemical species during the socioeconomic suppression period significantly decreased by 45%–61% compared to the values before this period. The OC/EC ratio (3.28 ± 0.61) and char-EC/soot-EC (4.88 ± 2.72) suggested that biomass burning, coal combustion, vehicle emissions, cooking activities are major PM2.5 sources in HCMC. Furthermore, the results of a concentration-weighted trajectory analysis suggested that the geological sources of PM2.5 were in the local areas of HCMC and the northeast provinces of Vietnam (where coal-fired power plants are located).
ISSN:1680-8584
2071-1409