Associations between mortality from COVID-19 in two Italian regions and outdoor air pollution as assessed through tropospheric nitrogen dioxide

Abstract

After the appearance of COVID-19 in China last December 2019, Italy was the first European country to be severely affected by the outbreak. The first diagnosis in Italy was on February 20, 2020, followed by the establishment of a light and a tight lockdown on February 23 and on March 8, 2020, respectively. The virus spread rapidly, particularly in the North of the country in the ‘Padan Plain’ area, known as one of the most polluted regions in Europe. Air pollution has been recently hypothesized to enhance the clinical severity of SARS-CoV-2 infection, acting through adverse effects on immunity, induction of respiratory and other chronic disease, upregulation of viral receptor ACE-2, and possible pathogen transportation as a virus carrier. We investigated the association between air pollution and subsequent COVID-19 mortality rates within two Italian regions (Veneto and Emilia-Romagna). We estimated ground-level nitrogen dioxide through its tropospheric levels using data available from the Sentinel satellites of the European Space Agency Copernicus program before the lockdown. We then examined COVID-19 mortality rates in relation to the nitrogen dioxide levels at three 14-day lag points after the lockdown, namely March 8, 22 and April 5. Using a multivariable negative binomial regression model, we found an association between nitrogen dioxide and COVID-19 mortality. Although ecological data provide only weak evidence, these findings indicate an association between air pollution levels and COVID-19 severity.

Spatial distribution characteristics of the COVID-19 pandemic in Beijing and its relationship with environmental factors

“…However, access to population activity data is difficult. The environmental factors chosen for the study were mainly those reflecting population activities, but other natural conditions (e.g., air pollution, temperature, humidity) play an essential role in the transmission of the virus (e.g., Filippini et al, 2020 ; Guo et al, 2020 ; Zhang et al, 2020 ). Therefore, in future studies, these data need to be incorporated into the models.…”

SARS-CoV-2 infection incidence during the first and second COVID-19 waves in Italy

“…There were no important local differences in attempted control until November 6, 2020, when area-specific policies driven by the local spread of the outbreak began ( DPCM, 2020 ). This history allows a relatively unconfounded comparison of the first and second waves of Covid-19 epidemiology during the February-October period between Italian communities, assuming that environmental and behavioral risk factors for Covid-19 such as outdoor air pollution, meteorological effects, and social interaction are close to uniform across Italy ( Ambika et al, 2021 ; Calina et al, 2021 ; Copat et al, 2020 ; Domingo and Rovira, 2020 ; Filippini et al, 2021 ; Filippini et al, 2020 ; Marques et al, 2021 ; Mele et al, 2021 ; Sidiropoulou et al, 2021 ; Sunyer et al, 2021 ; Tsatsakis et al, 2020b ). The vaccination campaign did not begin in Italy until December 27, 2020 ( Ministry of Health, 2021 ).…”

An Italian individual-level data study investigating on the association between air pollution exposure and Covid-19 severity in primary-care setting

“…Regions where most of the new cases and deaths are reported are still those of Northern Italy, and particularly Lombardy [ 7 ]. A large part of Northern Italy territory includes the Po basin area (Padan Plain), which is the most industrialized area of the country, and one of the most polluted region of Europe [ 8 ]. The World Health Organization (WHO), reported that air pollution is responsible for 7 million deaths worldwide every year, and represented one of the main concern regarding public health [ 9 ].…”