AIR POLLUTION IN CITIES WITH UNPLANNED URBAN GROWTH, A CASE STUDY OF TOLUCA VALLEY: TRENDS AND HEALTH IMPACTS COMPARED WITH MEXICO CITY

• DOI: https://doi.org/10.22533/at.ed.28524090810

• Palavras-chave: Contaminantes Criterio, Impacto a la salud, COVID-19, Crecimiento urbano no planificado

• Keywords: ACP, Health impact, COVID-19, Unplanned urban growth

• Abstract: Introduction: Unplanned urban growth is occurring in many cities in developing countries and is associated with social and environmental problems. The Metropolitan Area of Toluca Valley (MATV) began its disorganized expansion since the 1960s, and according to the IQAir platform, it has been the city with the worst air quality in Mexico, in terms of PM2.5, since 2019. Materials and methods: Ten-year (2011-2021) monitoring databases of air criteria pollutants (ACP) from six MATV monitoring stations were processed to establish spatiotemporal variations and to estimate the mortality proportion attributable to PM2.5 exposure using AirQ+ software. The evolution of ACP concentrations and the PM2.5 mortality proportion between the MATV and Mexico City were compared. The COVID-19 lockdown impact on ACP was also assessed. Results: PM2.5 and PM10 are the main ACP that worsen air quality in MATV and exceed the WHO Air Quality Guidelines (AQG) almost the entire year, risking public health. The estimated mortality proportion associated with PM2.5 exposure in 2019 for MATV was 11.97% (7.98-15.55) as for Mexico City, 6.95% (4.59-9.1). MATV presented higher levels of ACP and lower reduction percentages than Mexico City Metropolitan Area over the ten-year period. PM and O3 patterns are very similar between cities, suggesting that air pollution is shared. The COVID-19 lockdown in 2020 caused a reduction of all ACP concentrations except for O3. Conclusions: MATV case study provides a reference scenario of the impact of unplanned urban growth on public health and the need for the government to develop solutions to improve urban mobility and environmental surveillance.