{"title":"Effect of the COVID-19 Lockdown on Ambient Air Quality in Major Cities of Nepal.","authors":"Bashu Dev Baral, Kapil Thapa","doi":"10.5696/2156-9614-11.29.210211","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>The Nepalese government announced a nationwide lockdown beginning on March 24, 2020 as an attempt to restrain the spread of COVID-19. The prohibition in flight operations and movement of vehicles, factory shutdowns and restriction in people's movement due to the lockdown led to a significant reduction in the amounts of pollutants degrading air quality in many countries.</p><p><strong>Objectives: </strong>The present study aimed to analyze changes in particulate matter (PM) emissions and the air quality index (AQI) of six cities in Nepal i.e., Damak, Simara, Kathmandu, Pokhara, Nepalgunj and Surkhet due to the nationwide lockdown in response to the COVID-19 outbreak.</p><p><strong>Methods: </strong>Daily PM concentrations of each of the six study cities from January 24 to September 21, 2020 were obtained from the World Air Quality Index project (https://aqicn.org) and analyzed using R Studio software. The drop percentage was calculated to determine the change in PM<sub>2.5</sub> and PM<sub>10</sub> concentration during different time periods. Independent sample Mann-Whitney U tests were performed to test the significance of differences in mean concentration for each site during the lockdown period (24 March-24 July 2020) and its corresponding period in 2019. Similarly, the significance of differences in mean concentrations between the lockdown period and the period immediately before lockdown (23 January-23 March) was also examined using the same test.</p><p><strong>Results: </strong>During the lockdown period, in overall Nepal, AQI<sub>PM2.5</sub> and AQI<sub>PM10</sub> were within the moderate zone for the maximum number of days. As a result of the lockdown, the highest immediate and final drop of PM<sub>2.5</sub> was observed in Damak (26.37%) and Nepalgunj (80.86%), respectively. Similarly, the highest immediate drop of PM<sub>10</sub> was observed in Surkhet (37.22%) and finally in Nepalgunj (81.14%). Analysis with the Mann-Whitney U test indicated that for both PM types, all sites showed a statistically significant (p < 0.05) difference in mean concentrations during lockdown and the corresponding period in 2019.</p><p><strong>Conclusions: </strong>The present study explored the positive association between vehicular movement and PM emissions, highlighting the need for alternative fuel sources to improve air quality and human health.</p><p><strong>Competing interests: </strong>The authors declare no competing financial interests.</p>","PeriodicalId":52138,"journal":{"name":"Journal of Health and Pollution","volume":"11 29","pages":"210211"},"PeriodicalIF":2.4000,"publicationDate":"2021-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8009645/pdf/","citationCount":"10","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Health and Pollution","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.5696/2156-9614-11.29.210211","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/3/1 0:00:00","PubModel":"eCollection","JCR":"Q1","JCRName":"Medicine","Score":null,"Total":0}
引用次数: 10
Abstract
Background: The Nepalese government announced a nationwide lockdown beginning on March 24, 2020 as an attempt to restrain the spread of COVID-19. The prohibition in flight operations and movement of vehicles, factory shutdowns and restriction in people's movement due to the lockdown led to a significant reduction in the amounts of pollutants degrading air quality in many countries.
Objectives: The present study aimed to analyze changes in particulate matter (PM) emissions and the air quality index (AQI) of six cities in Nepal i.e., Damak, Simara, Kathmandu, Pokhara, Nepalgunj and Surkhet due to the nationwide lockdown in response to the COVID-19 outbreak.
Methods: Daily PM concentrations of each of the six study cities from January 24 to September 21, 2020 were obtained from the World Air Quality Index project (https://aqicn.org) and analyzed using R Studio software. The drop percentage was calculated to determine the change in PM2.5 and PM10 concentration during different time periods. Independent sample Mann-Whitney U tests were performed to test the significance of differences in mean concentration for each site during the lockdown period (24 March-24 July 2020) and its corresponding period in 2019. Similarly, the significance of differences in mean concentrations between the lockdown period and the period immediately before lockdown (23 January-23 March) was also examined using the same test.
Results: During the lockdown period, in overall Nepal, AQIPM2.5 and AQIPM10 were within the moderate zone for the maximum number of days. As a result of the lockdown, the highest immediate and final drop of PM2.5 was observed in Damak (26.37%) and Nepalgunj (80.86%), respectively. Similarly, the highest immediate drop of PM10 was observed in Surkhet (37.22%) and finally in Nepalgunj (81.14%). Analysis with the Mann-Whitney U test indicated that for both PM types, all sites showed a statistically significant (p < 0.05) difference in mean concentrations during lockdown and the corresponding period in 2019.
Conclusions: The present study explored the positive association between vehicular movement and PM emissions, highlighting the need for alternative fuel sources to improve air quality and human health.
Competing interests: The authors declare no competing financial interests.
期刊介绍：
The Journal of Health and Pollution (JH&P) was initiated with funding from the European Union and World Bank and continues to be a Platinum Open Access Journal. There are no publication or viewing charges. That is, there are no charges to readers or authors. Upon peer-review and acceptance, all articles are made available online. The high-ranking editorial board is comprised of active members who participate in JH&P submissions and editorial policies. The Journal of Health and Pollution welcomes manuscripts based on original research as well as findings from re-interpretation and examination of existing data. JH&P focuses on point source pollution, related health impacts, environmental control and remediation technology. JH&P also has an interest in ambient and indoor pollution. Pollutants of particular interest include heavy metals, pesticides, radionuclides, dioxins, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), air particulates (PM10 and PM2.5), and other severe and persistent toxins. JH&P emphasizes work relating directly to low and middle-income countries, however relevant work relating to high-income countries will be considered on a case-by-case basis.
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