COVID-19 Pandemic: A Wake-Up Call for Clean Air

Exposure to ambient air pollutants and acute respiratory distress syndrome risk in sepsis

PURPOSE

Exposures to ambient air pollutants may prime the lung enhancing risk of acute respiratory distress syndrome (ARDS) in sepsis. Our objective was to determine the association of short-, medium-, and long-term pollutant exposures and ARDS risk in critically ill sepsis patients.

METHODS

We analyzed a prospective cohort of 1858 critically ill patients with sepsis, and estimated short- (3 days), medium- (6 weeks), and long- (5 years) term exposures to ozone, nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), particulate matter < 2.5 μm (PM2.5), and PM < 10 μm (PM10) using weighted averages of daily levels from monitors within 50 km of subjects' residences. Subjects were followed for 6 days for ARDS by the Berlin Criteria. The association between each pollutant and ARDS was determined using multivariable logistic regression adjusting for preselected confounders. In 764 subjects, we measured plasma concentrations of inflammatory proteins at presentation and tested for an association between pollutant exposure and protein concentration via linear regression.

RESULTS

ARDS developed in 754 (41%) subjects. Short- and long-term exposures to SO2, NO2, and PM2.5 were associated with ARDS risk (SO2: odds ratio (OR) for the comparison of the 75-25th long-term exposure percentile 1.43 (95% confidence interval (CI) 1.16, 1.77); p < 0.01; NO2: 1.36 (1.06, 1.74); p = 0.04, PM2.5: 1.21 (1.04, 1.41); p = 0.03). Long-term exposures to these three pollutants were also associated with plasma interleukin-1 receptor antagonist and soluble tumor necrosis factor receptor-1 concentrations.

CONCLUSION

Short and long-term exposures to ambient SO2, PM2.5, and NO2 are associated with increased ARDS risk in sepsis, representing potentially modifiable environmental risk factors for sepsis-associated ARDS.

Impact of Global Climate Change on Pulmonary Health: Susceptible and Vulnerable Populations

As fossil fuel combustion continues to power the global economy, the rate of climate change is accelerating, causing severe respiratory health impacts and large disparities in the degree of human suffering. Hotter and drier climates lead to longer and more severe wildland fire seasons, impairing air quality around the globe. Hotter temperatures lead to higher amounts of ozone and particles, causing the exacerbation of chronic respiratory diseases and premature mortality. Longer pollen seasons and higher pollen concentrations provoke allergic airway diseases. In arid regions, accelerated land degradation and desertification are promoting dust pollution and impairing food production and nutritional content that are essential to respiratory health. Extreme weather events and flooding impede healthcare delivery and can lead to poor indoor air quality due to mold overgrowth. Climate and human activities that harm the environment and ecosystem may also affect the emergence and spread of viral infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and associated morbidity and mortality exacerbated by air pollution. Children and elderly individuals are more susceptible to the adverse health effects of climate change. Geographical and socioeconomic circumstances, together with a decreased capacity to adapt, collectively increase vulnerability to the adverse effects of climate change. Successful mitigation of anthropogenic climate change is dependent on the commitment of energy-intensive nations to manage greenhouse gas emissions, as well as societal support and response to aggravating factors. In this review, we focus on the respiratory health impacts of global climate change, with an emphasis on susceptible and vulnerable populations and low- and middle-income countries.

Pre-admission ambient air pollution and blood soot particles predict hospitalisation outcomes in COVID-19 patients

BACKGROUND

Air pollution exposure is one of the major risk factors for aggravation of respiratory diseases. We investigated whether exposure to air pollution and accumulated black carbon (BC) particles in blood were associated with coronavirus disease 2019 (COVID-19) disease severity, including the risk for intensive care unit (ICU) admission and duration of hospitalisation.

METHODS

From May 2020 until March 2021, 328 hospitalised COVID-19 patients (29% at intensive care) were recruited from two hospitals in Belgium. Daily exposure levels (from 2016 to 2019) for particulate matter with aerodynamic diameter <2.5 µm and <10 µm (PM2.5 and PM10, respectively), nitrogen dioxide (NO2) and BC were modelled using a high-resolution spatiotemporal model. Blood BC particles (internal exposure to nano-sized particles) were quantified using pulsed laser illumination. Primary clinical parameters and outcomes included duration of hospitalisation and risk of ICU admission.

RESULTS

Independent of potential confounders, an interquartile range (IQR) increase in exposure in the week before admission was associated with increased duration of hospitalisation (PM2.5 +4.13 (95% CI 0.74-7.53) days, PM10 +4.04 (95% CI 1.24-6.83) days and NO2 +4.54 (95% CI 1.53-7.54) days); similar effects were observed for long-term NO2 and BC exposure on hospitalisation duration. These effect sizes for an IQR increase in air pollution on hospitalisation duration were equivalent to the effect of a 10-year increase in age on hospitalisation duration. Furthermore, for an IQR higher blood BC load, the OR for ICU admission was 1.33 (95% CI 1.07-1.65).

CONCLUSIONS

In hospitalised COVID-19 patients, higher pre-admission ambient air pollution and blood BC levels predicted adverse outcomes. Our findings imply that air pollution exposure influences COVID-19 severity and therefore the burden on medical care systems during the COVID-19 pandemic.

Air pollution and COVID-19: clearing the air and charting a post-pandemic course: a joint workshop report of ERS, ISEE, HEI and WHO

Air pollution is now recognised by governments, international institutions and civil society as a major global public health risk factor. The health burden of air pollution is large: 509 000 premature deaths every year in Europe [1] and serious aggravations of heart and lung diseases that affect millions of patients, both children and adults. The European Environmental Agency estimated that in 2018 there were 417 000 premature deaths attributable to particulate matter with diameter <2.5 µm (PM2.5), 55 000 to NO2, and 20 600 to O3 in Europe (table 10.1 in EEA Report 9/2020 [2]). In addition, 4 805 800 years of life lost could be attributed to PM2.5, 623 600 to NO2, and 246 700 to O3 (table 10.2 in [2]). This “silent killer” is one the most important determinants of health, surpassed only by high blood pressure, tobacco use and poor diet. The coronavirus disease 2019 (COVID-19) pandemic has raised concerns about whether air pollution can increase the severity of disease and risk of death after infection, as well as facilitate the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Chronic lung disease patients are in the epicentre of the current crisis, as they are more vulnerable to both the adverse effects of a SARS-CoV-2 infection and air pollution exposure, as well as their possible interactions. At the same time, the lockdown measures to control the spread of COVID-19 brought historical short-term reductions in air pollution levels around the globe, and increasing general public interest and demand for clean air policies [3]. The COVID-19 pandemic, an emerging infectious disease probably caused by a spill over from animals, and its possible interactions with air pollution, is an existential reminder that we are a part of a larger ecosystem, and that human health is closely connected with the health of our environment and planet. Here we provide a short summary on the potential role of air pollution in the spread and worsening of health impacts of COVID-19, and on the influence of the pandemic on air pollution levels in Europe. Moreover, we outline the major lessons learned to chart a healthy post-pandemic course. This work summarises the key messages from a workshop that took place on 2 December, 2020, organised by the European Respiratory Society (ERS), the International Society for Environmental Epidemiology (ISEE) and the Health Effects Institute (HEI), endorsed by the World Health Organization (WHO), and hosted by the European Parliament Lung Health Group and the European Commission (table 1).

The potential role of air pollution in the worsening of health impacts of COVID-19, and the influence of the pandemic on air pollution levels in Europe is explored. This editorial outlines the major lessons learned to chart a healthy post-pandemic course. https://bit.ly/3hmbaya