Air quality in the Guadalajara metropolitan area improved in 2020, largely due to the drop in activities caused by the coronavirus pandemic, but has deteriorated this year, monitoring data indicates.
Data from the Sistema de Monitoreo Atmosférico (the system that measures five air pollutants at hourly intervals from ten stations located within the metro area) shows that 18 air quality alerts were issued last year after contamination in zones of the city reached levels that could be considered a danger to public health. The Jalisco Environment Agency (Semadet) issues a contingencia or alert when a station records a reading of 150 IMECAs (the air quality index used in Mexico) for a continuous period of at least two hours.
Just in the first six months of 2021, the number of alerts issued has rocketed to 43. In comparison, 64 contingencias were issued throughout the whole of 2019.