In this study, an analysis of the daily averages of Nitrogen Dioxide and Tropospheric Ozone is done because they are produced mainly during or because of the combustion of fossil fuels. Two time periods were studied (January 1 to March 14, and March 15 to December 31) for 2019 and 2020 in order to determine the relationship between the regulatory measures imposed by the government to contain COVID-19 and acute respiratory diseases in Mexico City. Using Google Sheets?s tools, the percentages of change in the atmospheric concentration for each pollutant in each period and year were calculated and then compared with the reduction in the number of infections from acute respiratory diseases in 2020. The reduction of Nitrogen Dioxide was enough to conclude that the general air quality in Mexico City improved, which resulted in fewer people hospitalized for acute respiratory diseases in 2020 compared to 2019. So, a conclusion can be made that the contingency period caused by the recent COVID-19 pandemic resulted in a reduction in the atmospheric concentrations of the pollutants studied and in a reduction in the number of people hospitalized for acute respiratory diseases related to these pollutants.