Analysis of Particulate Matter Concentration Changes before, during, and Post COVID-19 Lockdown: A Case Study from Victoria, Mexico

• Published in: Atmosphere 2022-05, Vol.13 (5), p.827
• Main Authors: Macías-Hernández, Bárbara A., Tello-Leal, Edgar
• Format: Article
• Language: English
• Subjects: Air pollution; Air quality; Coronaviruses; COVID-19; Emissions; Epidemics; lockdown; Monitoring systems; Nitrogen dioxide; Outdoor air quality; Pandemics; Particulate emissions; Particulate matter; PM10; PM2.5; Pollutants; Restrictions; Severe acute respiratory syndrome coronavirus 2; Shelter in place; Social distancing; Statistical analysis; Statistical methods; Suspended particulate matter; Traffic; Viral diseases
• ISSN: 2073-4433; 2073-4433
• DOI: 10.3390/atmos13050827

The lockdown measures implemented due to the SARS-CoV-2 pandemic to reduce the epidemic curve, in most cases, have had a positive impact on air quality indices. Our study describes the changes in the concentration levels of PM2.5 and PM10 during the lockdown and post-lockdown in Victoria, Mexico, considering the following periods: before the lockdown (BL) from 16 February to 14 March, during the lockdown (DL) from 15 March to 2 May, and in the partial lockdown (PL) from 3 May to 6 June. When comparing the DL period of 2019 and 2020, we document a reduction in the average concentration of PM2.5 and PM10 of −55.56% and −55.17%, respectively. Moreover, we note a decrease of −53.57% for PM2.5 and −51.61% for PM10 in the PL period. When contrasting the average concentration between the DL periods of 2020 and 2021, an increase of 91.67% for PM2.5 and 100.00% for PM10 was identified. Furthermore, in the PL periods of 2020 and 2021, an increase of 38.46% and 31.33% was observed for PM2.5 and PM10, respectively. On the other hand, when comparing the concentrations of PM2.5 in the three periods of 2020, we found a decrease between BL and DL of −50.00%, between BL and PL a decrease of −45.83%, and an increase of 8.33% between DL and PL. In the case of PM10, a decrease of −48.00% between BL and DL, −40.00% between BL and PL, and an increase of 15.38% between the DL and PL periods were observed. In addition, we performed a non-parametric statistical analysis, where a significant statistical difference was found between the DL-2020 and DL-2019 pairs (x2 = 1.204) and between the DL-2021 and DL-2019 pairs (x2 = 0.372), with a p