Assessing the Impact of Traffic Emissions on Fine Particulate Matter and Carbon Monoxide Levels in Hanoi through COVID-19 Social Distancing Periods
Abstract Hanoi, Vietnam, is usually ranked as one of the most polluted capital cities in terms of air quality, particularly PM2.5. However, there has not been enough data to determine the main source of this pollution. In this study, we utilized the rare opportunity of the COVID-19 social distancing...
Saved in:
| Main Authors: | , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Springer
2021-07-01
|
| Series: | Aerosol and Air Quality Research |
| Subjects: | |
| Online Access: | https://doi.org/10.4209/aaqr.210081 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1825197542723289088 |
|---|---|
| author | Nhung H. Le Bich-Thuy Ly Phong K. Thai Gia-Huy Pham Ich-Hung Ngo Van-Nguyet Do Thuy T. Le Luan V. Nhu Ha Dang Son Yen-Lien T. Nguyen Duong H. Pham Tuan V. Vu |
| author_facet | Nhung H. Le Bich-Thuy Ly Phong K. Thai Gia-Huy Pham Ich-Hung Ngo Van-Nguyet Do Thuy T. Le Luan V. Nhu Ha Dang Son Yen-Lien T. Nguyen Duong H. Pham Tuan V. Vu |
| author_sort | Nhung H. Le |
| collection | DOAJ |
| description | Abstract Hanoi, Vietnam, is usually ranked as one of the most polluted capital cities in terms of air quality, particularly PM2.5. However, there has not been enough data to determine the main source of this pollution. In this study, we utilized the rare opportunity of the COVID-19 social distancing to assess the contribution of traffic emission to PM2.5 and CO levels when traffic volume was reduced significantly in Hanoi. Hourly PM2.5 and CO concentrations were measured from nine urban and traffic monitoring stations during pre-, soft, hard, and post-social distancing periods. As a result, we observed large reductions in both PM2.5 and CO levels during social distancing periods. PM2.5 concentrations were 14–18% lower during the social distancing than before this period, while CO concentrations had a more considerable drop by 28–41%. It is known that meteorological conditions can have significant effects on the ambient levels of air pollutants. To overcome this challenge, weather normalized concentrations of those pollutants were estimated using the random forest model, a machine learning technique. The normalized weather concentrations showed smaller reductions by 7–10% for PM2.5 and 5–11% for CO, indicating the presence of favorable weather conditions for better air quality during the social distancing period. In further analysis, the apparent improvement of air quality in Hanoi during the social distancing period was in line with reducing traffic emissions while emissions from coal-fired power plants remained relatively stable. |
| format | Article |
| id | doaj-art-dedeeb04215146198c11ae92de1e3d6e |
| institution | Kabale University |
| issn | 1680-8584 2071-1409 |
| language | English |
| publishDate | 2021-07-01 |
| publisher | Springer |
| record_format | Article |
| series | Aerosol and Air Quality Research |
| spelling | doaj-art-dedeeb04215146198c11ae92de1e3d6e2025-02-09T12:21:08ZengSpringerAerosol and Air Quality Research1680-85842071-14092021-07-01211011610.4209/aaqr.210081Assessing the Impact of Traffic Emissions on Fine Particulate Matter and Carbon Monoxide Levels in Hanoi through COVID-19 Social Distancing PeriodsNhung H. Le0Bich-Thuy Ly1Phong K. Thai2Gia-Huy Pham3Ich-Hung Ngo4Van-Nguyet Do5Thuy T. Le6Luan V. Nhu7Ha Dang Son8Yen-Lien T. Nguyen9Duong H. Pham10Tuan V. Vu11Live & Learn for Environment and CommunitySchool of Environmental Science and Technology, Hanoi University of Science and TechnologyQueensland Alliance for Environmental Health Sciences (QAEHS), The University of QueenslandGraduate School of Global Environmental Studies, Kyoto UniversitySchool of Environmental Science and Technology, Hanoi University of Science and TechnologyLive & Learn for Environment and CommunityHanoi Environmental Protection Agency, Department of Natural Resources and EnvironmentMinistry of Natural Resources and Environment, Northern Center for Environmental MonitoringCentre for Energy and Green Growth ResearchFaculty of Transport Safety and Environment, University of Transport and CommunicationsHanoi Environmental Protection Agency, Department of Natural Resources and EnvironmentEnvironmental Research Group, School of Public Health, Imperial College LondonAbstract Hanoi, Vietnam, is usually ranked as one of the most polluted capital cities in terms of air quality, particularly PM2.5. However, there has not been enough data to determine the main source of this pollution. In this study, we utilized the rare opportunity of the COVID-19 social distancing to assess the contribution of traffic emission to PM2.5 and CO levels when traffic volume was reduced significantly in Hanoi. Hourly PM2.5 and CO concentrations were measured from nine urban and traffic monitoring stations during pre-, soft, hard, and post-social distancing periods. As a result, we observed large reductions in both PM2.5 and CO levels during social distancing periods. PM2.5 concentrations were 14–18% lower during the social distancing than before this period, while CO concentrations had a more considerable drop by 28–41%. It is known that meteorological conditions can have significant effects on the ambient levels of air pollutants. To overcome this challenge, weather normalized concentrations of those pollutants were estimated using the random forest model, a machine learning technique. The normalized weather concentrations showed smaller reductions by 7–10% for PM2.5 and 5–11% for CO, indicating the presence of favorable weather conditions for better air quality during the social distancing period. In further analysis, the apparent improvement of air quality in Hanoi during the social distancing period was in line with reducing traffic emissions while emissions from coal-fired power plants remained relatively stable.https://doi.org/10.4209/aaqr.210081COVID-19Air qualityHanoiSoutheast AsiaWeather normalization |
| spellingShingle | Nhung H. Le Bich-Thuy Ly Phong K. Thai Gia-Huy Pham Ich-Hung Ngo Van-Nguyet Do Thuy T. Le Luan V. Nhu Ha Dang Son Yen-Lien T. Nguyen Duong H. Pham Tuan V. Vu Assessing the Impact of Traffic Emissions on Fine Particulate Matter and Carbon Monoxide Levels in Hanoi through COVID-19 Social Distancing Periods Aerosol and Air Quality Research COVID-19 Air quality Hanoi Southeast Asia Weather normalization |
| title | Assessing the Impact of Traffic Emissions on Fine Particulate Matter and Carbon Monoxide Levels in Hanoi through COVID-19 Social Distancing Periods |
| title_full | Assessing the Impact of Traffic Emissions on Fine Particulate Matter and Carbon Monoxide Levels in Hanoi through COVID-19 Social Distancing Periods |
| title_fullStr | Assessing the Impact of Traffic Emissions on Fine Particulate Matter and Carbon Monoxide Levels in Hanoi through COVID-19 Social Distancing Periods |
| title_full_unstemmed | Assessing the Impact of Traffic Emissions on Fine Particulate Matter and Carbon Monoxide Levels in Hanoi through COVID-19 Social Distancing Periods |
| title_short | Assessing the Impact of Traffic Emissions on Fine Particulate Matter and Carbon Monoxide Levels in Hanoi through COVID-19 Social Distancing Periods |
| title_sort | assessing the impact of traffic emissions on fine particulate matter and carbon monoxide levels in hanoi through covid 19 social distancing periods |
| topic | COVID-19 Air quality Hanoi Southeast Asia Weather normalization |
| url | https://doi.org/10.4209/aaqr.210081 |
| work_keys_str_mv | AT nhunghle assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT bichthuyly assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT phongkthai assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT giahuypham assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT ichhungngo assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT vannguyetdo assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT thuytle assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT luanvnhu assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT hadangson assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT yenlientnguyen assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT duonghpham assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods AT tuanvvu assessingtheimpactoftrafficemissionsonfineparticulatematterandcarbonmonoxidelevelsinhanoithroughcovid19socialdistancingperiods |