Air Quality Index and Ozone Environmental Contingencies in the Megalopolis of the Metropolitan Zone of the Valley of Mexico

Abstract The Megalopolis of the Mexico Valley Metropolitan Area (MZMVM) is one of the most polluted regions in the country. With its high population density and industrial activity, the MZMVM has recurrent ozone pollution episodes due to meteorological conditions and emissions of precursors such as nitrogen oxides and volatile organic compounds. The study of ozone is crucial due to its severe effects on human health, vegetation degradation, and air quality. The methodology used included the analysis of the air quality index and the occurrence of environmental contingencies from 2001 to 2022. Data from 80 monitoring stations distributed in the seven states constituting the MZMVM were used. The data were validated and processed according to Mexican and international standards. The results show an improvement in air quality in Mexico City and the State of Mexico, while a deterioration was observed in Hidalgo and Morelos during the study period. Although environmental emergencies due to ozone are now less frequent, they still represent a significant risk to public health and should be analyzed. This analysis highlights the importance of implementing stricter and more sustainable policies to reduce emissions of ozone precursors and protect both human health and the environment.