SARS-CoV-2: Air pollution highly correlated to the increase in mortality. The case of Guadalajara, Jalisco, México.

Objectives: To determine whether air pollution or changes in SARS-CoV-2 lineages lead to an increase in mortality. Methods: Descriptive statistics were used to calculate rates of infection (2020-2021). RT-PCR was used to compare viral loads from October 2020 to February 2021. Next-generation sequencing (NGS) (n = 92) was used to examine and phylogenetically map SARS-CoV-2 lineages. A correlative "air pollution/temperature" index (I) was developed using regression analysis. PM2.5, PM10, O3, NO2, SO2, and CO concentrations were analyzed and compared to the mortality. Results: The mortality rate during the last year was ∼32%. Relative SARS-CoV-2 viral loads increased in December 2020 and January 2021. NGS revealed that approximately 80% of SARS-CoV-2 linages were B.1.243 (33.7%), B1.1.222 (11.2%), B.1.1 (9%), B.1 (7%), B.1.1.159 (7%), and B.1.2 (7%). Two periods were analyzed, the prehigh- and high-mortality periods and no significant lineage differences or new lineages were found. Positive correlations of air pollution/temperature index values with mortality were found for IPM2.5 and IPM10. INO2. ISO2, and ICO but not for O3. Using ICO, we developed a model to predict mortality with an estimated variation of ∼±5 deaths per day. Conclusion: The mortality rate in the MZG was highly correlated with air pollution indices and not with SARS-CoV-2 lineage.