Possible synergistic effect of air pollution on increasing severity of SARS-CoV-2

Abstract

SARS-CoV-2 infection started in the last days of 2019 in China and affected a great number of people worldwide, causing many deaths in numerous countries. Major clinical symptoms of the infected patients are found to be fever, cough, and shortening of breath leading to acute respiratory distress syndrome (ARDS). Cytokine storm and inflammatory responses have been introduced as the main causes of respiratory distress in severe cases. Moreover, all these inflammatory factors have been systematically expressed in the human body through chronic exposure to ambient pollution due to an industrial lifestyle and lead to respiratory problems. In order to assess the possible synergistic effect of air pollution on the increased severity of COVID-19, the number of days and the value of air quality index (AQI) as well as the amount of four ambient pollutants (PM_2.5, PM₁₀, O₃, and NO₂) with unhealthy ranges were measured for three years in eight cities of Iran with different numbers of hospitalized patients affected with SARS-CoV-2.  The correlation coefficient between the number of hospitalized patients and air pollution factors was calculated. The present data revealed a significant positive correlation between unhealthy ranges of O₃ and NO₂ and the number of hospitalized patients with COVID-19. No correlation was found between PM_2.5, PM₁₀, and AQIs and the increased number of severe cases. Conclusively, these primary results might show the synergistic effect of chronic exposure to air pollutants due to living in polluted areas and the increased severity of COVID-19 disease.

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Tables

Table 1. The result of general population census in eight provinces. 

* PR: Province area (Km^2)

**RPD: Relative population density (People per square kilometer)

Az.: Azarbayejan, Kho.: Khorasan