Impact of outdoor air pollution on severity and mortality in COVID-19 pneumonia

O Bronte; F García-García; D-J Lee; I Urrutia; A Uranga; M Nieves; J Martínez-Minaya; J M Quintana; I Arostegui; R Zalacain; L A Ruiz-Iturriaga; L Serrano; R Menéndez; R Méndez; A Torres; C Cilloniz; P P España; COVID-19 & Air Pollution Working Group

doi:10.1016/j.scitotenv.2023.164877

Impact of outdoor air pollution on severity and mortality in COVID-19 pneumonia

Sci Total Environ. 2023 Oct 10:894:164877. doi: 10.1016/j.scitotenv.2023.164877. Epub 2023 Jun 17.

Authors

O Bronte¹, F García-García², D-J Lee², I Urrutia³, A Uranga³, M Nieves³, J Martínez-Minaya⁴, J M Quintana⁵, I Arostegui⁶, R Zalacain⁷, L A Ruiz-Iturriaga⁷, L Serrano⁷, R Menéndez⁸, R Méndez⁸, A Torres⁹, C Cilloniz¹⁰, P P España³; COVID-19 & Air Pollution Working Group

Affiliations

¹ Galdakao-Usansolo University Hospital, Pulmonology Department, Galdakao, Spain; BioCruces Bizkaia Health Research Institute, Baracaldo, Spain. Electronic address: obronte001@ikasle.ehu.eus.
² Basque Center for Applied Mathematics (BCAM), Bilbao, Spain.
³ Galdakao-Usansolo University Hospital, Pulmonology Department, Galdakao, Spain; BioCruces Bizkaia Health Research Institute, Baracaldo, Spain.
⁴ Universitat Politècnica de València, Valencia, Spain.
⁵ Galdakao-Usansolo University Hospital, Research Unit, Galdakao, Spain.
⁶ University of the Basque Country (UPV/EHU), Department of Applied Mathematics, Statistics and Operative Research, Leioa, Spain; Basque Center for Applied Mathematics (BCAM), Bilbao, Spain.
⁷ Cruces University Hospital, Pulmonology Department, Baracaldo, Spain; BioCruces Bizkaia Health Research Institute, Baracaldo, Spain.
⁸ Hospital Universitari i Politècnic La Fe de Valencia, Pulmonology Department, Valencia, Spain.
⁹ Hospital Clínic i Provincial de Barcelona, Pulmonology Department, University of Barcelona, Barcelona, Spain.
¹⁰ Hospital Clínic i Provincial de Barcelona, Pulmonology Department, University of Barcelona, Barcelona, Spain; Faculty of Health Sciences, Continental University, Huancayo, Peru.

Abstract

The relationship between exposure to air pollution and the severity of coronavirus disease 2019 (COVID-19) pneumonia and other outcomes is poorly understood. Beyond age and comorbidity, risk factors for adverse outcomes including death have been poorly studied. The main objective of our study was to examine the relationship between exposure to outdoor air pollution and the risk of death in patients with COVID-19 pneumonia using individual-level data. The secondary objective was to investigate the impact of air pollutants on gas exchange and systemic inflammation in this disease. This cohort study included 1548 patients hospitalised for COVID-19 pneumonia between February and May 2020 in one of four hospitals. Local agencies supplied daily data on environmental air pollutants (PM₁₀, PM_2.5, O₃, NO₂, NO and NO_X) and meteorological conditions (temperature and humidity) in the year before hospital admission (from January 2019 to December 2019). Daily exposure to pollution and meteorological conditions by individual postcode of residence was estimated using geospatial Bayesian generalised additive models. The influence of air pollution on pneumonia severity was studied using generalised additive models which included: age, sex, Charlson comorbidity index, hospital, average income, air temperature and humidity, and exposure to each pollutant. Additionally, generalised additive models were generated for exploring the effect of air pollution on C-reactive protein (CRP) level and SpO₂/FiO₂ at admission. According to our results, both risk of COVID-19 death and CRP level increased significantly with median exposure to PM₁₀, NO₂, NO and NO_X, while higher exposure to NO₂, NO and NO_X was associated with lower SpO₂/FiO₂ ratios. In conclusion, after controlling for socioeconomic, demographic and health-related variables, we found evidence of a significant positive relationship between air pollution and mortality in patients hospitalised for COVID-19 pneumonia. Additionally, inflammation (CRP) and gas exchange (SpO₂/FiO₂) in these patients were significantly related to exposure to air pollution.

Keywords: Air pollution; COVID-19; Individual-level data; Mortality; Pneumonia; SARS-CoV-2.

MeSH terms

Air Pollutants* / analysis
Air Pollution* / analysis
Bayes Theorem
COVID-19*
Cohort Studies
Environmental Exposure / analysis
Humans
Inflammation / chemically induced
Nitrogen Dioxide / analysis
Particulate Matter / analysis
Pneumonia* / chemically induced
Pneumonia* / epidemiology

Substances

Nitrogen Dioxide
Air Pollutants
Particulate Matter