Geospatial Correlation Analysis between Air Pollution Indicators and Estimated Speed of COVID-19 Diffusion in the Lombardy Region (Italy).

Lorenzo Gianquintieri,Enrico Gianluca Caiani,Giuseppe Maria Sechi,Maria Antonia Brovelli,Andrea Pagliosa,Rodolfo Bonora

doi:10.3390/ijerph182212154

Abstract

Background: the Lombardy region in Italy was the first area in Europe to record an outbreak of COVID-19 and one of the most affected worldwide. As this territory is strongly polluted, it was hypothesized that pollution had a role in facilitating the diffusion of the epidemic, but results are uncertain. Aim: the paper explores the effect of air pollutants in the first spread of COVID-19 in Lombardy, with a novel geomatics approach addressing the possible confounding factors, the reliability of data, the measurement of diffusion speed, and the biasing effect of the lockdown measures. Methods and results: all municipalities were assigned to one of five possible territorial classes (TC) according to land-use and socio-economic status, and they were grouped into districts of 100,000 residents. For each district, the speed of COVID-19 diffusion was estimated from the ambulance dispatches and related to indicators of mean concentration of air pollutants over 1, 6, and 12 months, grouping districts in the same TC. Significant exponential correlations were found for ammonia (NH3) in both prevalently agricultural (R2 = 0.565) and mildly urbanized (R2 = 0.688) areas. Conclusions: this is the first study relating COVID-19 estimated speed of diffusion with indicators of exposure to NH3. As NH3 could induce oxidative stress, its role in creating a pre-existing fragility that could have facilitated SARS-CoV-2 replication and worsening of patient conditions could be speculated.

Highlights

Diffusion of the pandemic could be inferred by the analysis of georeferenced Emergency Medical Services (EMS) interventions for respiratory problems, which is an approach we recently proposed and validated [36]
The reliability of analyzed data, by considering the number of ambulances dispatches for respiratory issues; The management of confounding factors, by comparing only territories with similar land-use characteristics; Considering the time component, by focusing on the initial spread of the disease, to avoid biases introduced by effect of lockdown measures;
We could speculate that oxidative stress, as one of the toxicity mechanisms associated to NH3, could have contributed to a pre-existing fragility due to inflammatory status in residents of those areas, facilitating virus replication and further worsening of clinical conditions that required the intervention of EMS

Summary

Introduction

The epidemic of coronavirus disease 2019 (COVID-19), generated by the diffusion of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), officially started in. On 21 February 2020, when the first case was diagnosed in the hospital of Codogno (Lodi province), which is a small city in the south of Lombardy region, the most populated area of Italy with 10.06 million resident people (16.67% of the total 60.36 million people living in Italy). The Lombardy region was the first area in all of Europe to record an endemic outbreak of COVID-19 and became one of the most affected all over the world during the first peak, with 78,105 confirmed cases (0.78% on the total population) reached at.

Objectives

Methods

Results

Discussion

Conclusion