TITLE Association between environmental levels of PM 2.5 and mortality from SARS-CoV-2 in inhabitants of Mexico City AUTHORS AND AFFILLATIONS Moreno-Santillan Armando Alberto, (1) Rivas-Ruiz Rodolfo, (2) Fuentes-Valdivieso Rocio, (3) Roy-Garcia Ivonne Anali. (2) 1. General Hospital of Mexico “Dr. Eduardo Liceaga”. Mexico City. 2. Mexican Social Security Institute. Health Research Coordination. XXI Century National Medical Center. Mexico City. 3. Higher School of Medicine. National Polytechnic Institute. Mexico City. Corresponding Author Dr. Rodolfo Rivas Ruiz. Email: rivasrodolfo@gmail.com Acknowledgment To the National Polytechnic Institute, Mexico. SUMMARY Objective. To evaluate the association between exposure to environmental levels of PM 2.5 and mortality from SARS-CoV-2 in inhabitants of Mexico City. Material and methods. A secondary analysis with the total number of deaths from COVID-19 in residents of Mexico City as well as 25 municipalities in the interior of the Republic was carried out. Environmental levels of PM 2.5 were between 2018 and 2021. Bivariate analysis and multivariate logistic regression were performed. Results. A total of 1,083,175 cases of COVID-19 were included, with 57,384 deaths (5.3%), of which 30,561 were in residents with exposure to more than 20 μg/m 3 of PM 2.5 (OR 1.27, CI95%: 1.25 to 1.29). When performing the multivariate analysis, an OR of 1.39 (CI95%: 1.36 to 1.43) was observed. Conclusions. Chronic exposure to elevated levels of PM 2.5 is associated with increased death risk from COVID-19. Keywords. COVID-19, environmental pollution, PM 2.5 , death. . CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted May 10, 2022. ; https://doi.org/10.1101/2022.05.08.22274818 doi: medRxiv preprint NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice.