Statistical Analysis for Understanding PM2.5 Air Quality and the Impacts of COVID-19 Social Distancing in Several Provinces and Cities in Vietnam

Giang Tran Huong Nguyen; Huy Hoang-Cong; Luan Thien La

doi:10.1007/s11270-023-06113-1

Statistical Analysis for Understanding PM_2.5 Air Quality and the Impacts of COVID-19 Social Distancing in Several Provinces and Cities in Vietnam

Water Air Soil Pollut. 2023;234(2):85. doi: 10.1007/s11270-023-06113-1. Epub 2023 Jan 26.

Authors

Giang Tran Huong Nguyen¹, Huy Hoang-Cong², Luan Thien La³

Affiliations

¹ Department of Chemistry and Environment, Dalat University, 1 Phu Dong Thien Vuong Street, Da Lat, Lam Dong Vietnam.
² Northern Center for Environmental Monitoring, Environmental Pollution Control Department, Ha Noi, Vietnam.
³ Environmental Protection Agency, Lam Dong province Department of Natural Resources and Environment, Da Lat, Lam Dong Vietnam.

Abstract

Air pollution, especially in urban regions, is receiving increasing attention in Vietnam. Consequently, this work aimed to study and analyze the air quality in several provinces and cities in the country focusing on PM_2.5. Moreover, the impacts of COVID-19 social distancing on the PM_2.5 level were investigated. For this purpose, descriptive statistic, Box and Whisker plot, correlation matrix, temporal variation, and trend analysis were conducted. R-based program and the R package "openair" were employed for the calculations. Hourly PM_2.5 data were obtained from 8 national air quality monitoring sites. The study results indicated that provinces and cities in the North experienced more PM_2.5 pollution compared to the Central and South. PM_2.5 concentrations at each monitoring site varied significantly. Among monitoring sites, the northern sites showed high PM_2.5 correlations with each other than the other sites. Seasonal variation was observed with high PM_2.5 concentration in the dry season and low PM_2.5 concentration in the wet season. PM_2.5 concentration variation during the week was not so different. Diurnal variation showed that PM_2.5 concentration rose at peak traffic hours and dropped in the afternoon. There was mainly a decreasing trend in PM_2.5 concentration over the studied period. The COVID-19 pandemic has contributed to PM_2.5 reduction. In the months implemented social distancing for preventing the epidemic, PM_2.5 concentration declined but it would mostly increase in the following months. This study provided updated and valuable assessments of recent PM_2.5 air quality in Vietnam.

Keywords: Air pollution; COVID-19; Fine particulate matter; Statistical analysis; Statistical software R.

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