The diverse advances in air quality research, especially those related to PM2.5, have shown that this parameter affects health greatly.In addition, its presence in the atmosphere is the product of different anthropogenic activities.The objective of this study was to simultaneously analyze the relationship between the behavior of PM2.5 and the preventive isolation required by COVID-19, through surface data in a characteristic residential area of the Aburrá Valley-Colombia.Comparing the levels before and during the health emergency, data was collected from April 3, 2019 to October 31, 2021 for a period of 24 ± 1 hours.During this period, the average concentration of PM2.5 was 19.1 μg/m 3 , with a maximum and minimum of 60.9 and 2.1 μg/m 3 , respectively.In relation to the period before the pandemic, 13.9% of the data represented good air quality within the limits recommended by the World Health Organization (WHO: PM2.5 < 13 μg/ m 3 ) in contrast to an increase of 57% during the health emergency, evidencing the positive impact of the restrictive measures of emission sources.However, atypical data were identified in the range of 40 to 60 μg/m 3 , attributed to air quality management episodes, related to the impact of external events associated with the effect of aerosol intrusion into the Aburrá Valley due to biomass burning on the Colombia-Venezuela border and the north of the country, with representative contributions of high importance.