Can long-term publicity to air air pollution affect COVID-19 severity?

A latest examine revealed in Environmental Research examined the consequences of long-term publicity to air pollution on coronavirus illness 2019 (COVID-19) morbidity and mortality.

Study: Long-term air pollution exposure and COVID-19 case-severity:An analysis of individual-level data from Switzerland. Image Credit: Lemberg Vector studio/Shutterstock
Examine: Long-term air pollution exposure and COVID-19 case-severity:An analysis of individual-level data from Switzerland. Picture Credit score: Lemberg Vector studio/Shutterstock


A number of research recommend that publicity to air pollution may enhance susceptibility to and irritate the scientific course of COVID-19. Nonetheless, most research investigating the impression of air air pollution have carried out ecological examine designs. Examples embrace regression analyses assessing the affiliation of air air pollution with COVID-19 incidence, severity, and mortality.

A limitation of ecological regression analyses within the context of COVID-19 is that they don’t account for threat elements at a person degree. The person-level threat elements extremely affect COVID-19 outcomes.

An evaluation of methodological concerns for epidemiologic research of COVID-19 and air air pollution concluded that ecological investigations are topic to bias.

Concerning the new examine

Within the current examine, researchers evaluated whether or not modifications in air air pollution in Switzerland affected COVID-19 severity and mortality. They obtained the COVID-19 dataset akin to information from February 2, 2020, to April 30, 2021, from the Swiss Federal Workplace of Public Well being. It contained individual-level information on sufferers’ age, smoking standing, intercourse, gender, COVID-19 standing, hospitalization, intensive care unit (ICU) admission, loss of life, and comorbidities.

Moreover, the workforce collected data on socioeconomic elements, well being system-related elements, and municipality-level local weather information. Air air pollution information for 2014 to 2019 had been modeled on a European scale at a spatial decision of 1 km2.

The workforce carried out a Bayesian geostatistical modeling framework that built-in information from the Swiss nationwide observations community (NABEL), pan-European in-situ monitoring community (Eionet), high-resolution satellite-based proxies of nitrogen dioxide (NO2) and particulate matter (PM), high-resolution merchandise on local weather, meteorology, and land cowl.

Socioeconomic information had been accessed from the Statistical Atlas of Switzerland. The information comprised indices on inhabitants distribution, dwelling circumstances, the nationwide language, urbanization standing, financial indicators, and distribution of deaths. Moreover, the Atlas was additionally accessed for information on healthcare system-related elements, equivalent to hospital capability and the variety of employees.

Solely hospitalized sufferers had been included within the analyses. Two outcomes had been measured for COVID-19 severity, ICU admission, and loss of life. Univariate analyses evaluated the associations of ICU admission and loss of life with particular person patient-level traits. For multivariate modeling, sufferers missing data on intercourse and municipality had been excluded. Comorbidities had been categorized into teams of zero, one, two, and three or extra comorbidities.

Analyses had been individually carried out for 2 temporal scales – the primary COVID-19 wave (earlier than October 2020) and the general time sequence. Bayesian variable choice (BVS) was utilized to determine outcomes-associated elements. The likelihood of NO­2 and PM2.5 inclusion in multivariable fashions had been individually assessed.


The researchers analyzed 28,540 sufferers hospitalized with COVID-19. Of those, 5849 required ICU admission, and 5234 succumbed to an infection. Univariate associations revealed that superior age will increase the percentages of ICU admission and loss of life. Being male was additionally related to larger odds of extreme COVID-19. The chances of extreme illness outcomes (ICU and loss of life) elevated when sufferers had been comorbid.

There have been decrease odds of severity for diabetes and adiposity however larger odds for most cancers and continual renal and cardiovascular ailments. Sufferers with none earlier sickness had been 70% much less prone to be admitted to ICU and 80% much less prone to die. Extreme COVID-19 outcomes had been totally different in the course of the first wave of COVID-19 in comparison with your complete interval.

The danger of ICU admission was 25.1% within the first wave in comparison with 20.5% total. Equally, the mortality threat was larger within the first wave (20.5%) than throughout the entire interval (18.3%). BVS recognized predictors related to illness severity. Sixteen fashions had been fitted, akin to the mix of two outcomes, two intervals, two air pollution (NO2 and PM2.5), and two mannequin varieties (spatial and unbiased).

The authors famous that spatial fashions outperformed unbiased non-spatial fashions. The outcomes from multivariate spatial fashions had been just like these from univariate evaluation. Superior age and male intercourse had been related to elevated odds of ICU admission and loss of life, no matter pollutant or temporal scale.

Increased NO2 concentrations elevated the percentages of each outcomes within the first wave, whereas elevated PM2.5 concentrations solely elevated the chance of loss of life. The authors famous that the magnitude of pollution-related regression coefficients was decrease than that of particular person threat elements.

Within the first wave, larger air temperature decreased the chance of each outcomes, and the percentages of ICU admission elevated in municipalities the place 5 or extra folks lived in a family.


In abstract, the findings demonstrated that publicity to air pollution was related to COVID-19 severity solely in the course of the first wave of the pandemic when the nationwide well being system was much less ready.

Notably, individual-level traits had been important elements associated to (extreme) outcomes in all fashions. Total, the findings assist enhance our understanding of the impression of publicity to air pollution on COVID-19 morbidity and mortality.

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