Why Air Quality Matters

Feb. 25, 2022

The ABCs of Emergency First Aid, acknowledge “Airway” and “Breathing,” as the first things to assess when attempting life-saving resuscitation.  From individual, public and planetary health perspectives we can take guidance from this primary medical objective.  The Air we breathe is essential to all life and has direct, immediate and profound impacts on human health.

Described by Health Canada as, “the most important environmental contributor to poor health and premature death,” poor air quality is directly associated with the incidence and severity of most heart and lung diseases; while also contributing to cancers and countless other chronic conditions, including diabetes and dementia.  Emerging epidemiological evidence shows poor air quality greatly increases susceptibility to respiratory viruses and weakens one’s immune response. 

Airborne Pollution, such as smog and wildfire smoke, contain PM2.5 and Nitrous oxides (NOx), which have been strongly correlated with the severity of all SARS/MERS (coronavirus) outbreaks to date. Robust research out of the US shows small increases in particulate matter pollution (1 μg/m3 of PM 2.5) has been associated with a significant (8%) increase in COVID-19 deaths (1).  Regions across the globe experiencing some of the most severe outcomes of the pandemic occurred where air pollution was highest (6).

In British Columbia, wildfire smoke is understood as a growing threat to air quality and public health. The record setting wildfire seasons of 2017/18 acutely measured how health care costs, hospital admissions and mortality rates are impacted by poor air quality (BC Lung 16th Annual Conference). While the data was based on the immediate impacts of wildfire smoke on health, the long-term consequences are more difficult to analyse.

On one hand, it is understood that the serious diseases caused by air pollution are known ‘co-morbidities,’ increasing the risk of hospitalization and death with SARS/COV2. On the other, specific pollutants, such as nitrogen oxides and PM2.5 are being shown to have direct impacts on an individuals susceptibility to the virus. Review of available data suggests both short- and long-term exposures to air pollution are important aggravating factors for viral transmission and severity of disease through a number of different mechanisms (explore this in the research papers below).

In light of this growing evidence, alongside the reality that the virus known as COVID-19, is but one of countless respiratory infections humanity will have to deal with over the long haul, it is extremely important air quality be addressed in pandemic recovery plans. The ABCs of Public Health demand it!

Research Publications

  1. Exposure to air pollution and COVID-19 mortality in the United States: A nationwide cross-sectional study https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7277007/
  2. Assessing nitrogen dioxide (NO2) levels as a contributing factor to coronavirus (COVID-19) fatality  https://www.sciencedirect.com/science/article/pii/S0048969720321215
  3. Association between short-term exposure to air pollution and COVID-19 infection: Evidence from China https://www.sciencedirect.com/science/article/pii/S004896972032221X?via%3Dihub 
  4. Air pollution and case fatality of SARS in the People’s Republic of China: an ecologic study – https://ehjournal.biomedcentral.com/articles/10.1186/1476-069X-2-15 – 
  5. Air pollution by NO 2 and PM 2.5 explains COVID-19 infection severity by overexpression of angiotensin-converting enzyme 2 in respiratory cells: a review https://pubmed.ncbi.nlm.nih.gov/32982622/ 
  6. Effects of air pollutants on the transmission and severity of respiratory viral infections https://pubmed.ncbi.nlm.nih.gov/32416357/ 
  7. Influence of airborne transmission of SARS-CoV-2 on COVID-19 pandemic. A review https://pubmed.ncbi.nlm.nih.gov/32718835/ Abstract: In recent years, a number of epidemiological studies have demonstrated that exposure to air pollution is associated with several adverse outcomes, such as acute lower respiratory infections, chronic obstructive pulmonary disease, asthma, cardiovascular diseases, and lung cancer among other serious diseases. Air pollutants such as sulfur oxides, nitrogen oxides, carbon monoxide and dioxide, particulate matter (PM), ozone and volatile organic compounds (VOCs) are commonly found at high levels in big cities and/or in the vicinity of different chemical industries. An association between air concentrations of these pollutants and human respiratory viruses interacting to adversely affect the respiratory system has been also reported. The present review was aimed at assessing the potential relationship between the concentrations of air pollutants on the airborne transmission of SARS-CoV-2 and the severity of COVID-19 in patients infected by this coronavirus. The results of most studies here reviewed suggest that chronic exposure to certain air pollutants leads to more severe and lethal forms of COVID-19 and delays/complicates the recovery of patients of this disease.
  8. The impact of outdoor air pollution on COVID-19: a review of evidence from in vitro, animal, and human studies https://err.ersjournals.com/content/30/159/200242 Abstract: Studies have pointed out that air pollution may be a contributing factor to the coronavirus disease 2019 (COVID-19) pandemic. However, the specific links between air pollution and severe acute respiratory syndrome-coronavirus-2 infection remain unclear. Here we provide evidence from in vitro, animal and human studies from the existing literature. Epidemiological investigations have related various air pollutants to COVID-19 morbidity and mortality at the population level, however, those studies suffer from several limitations. Air pollution may be linked to an increase in COVID-19 severity and lethality through its impact on chronic diseases, such as cardiopulmonary diseases and diabetes. Experimental studies have shown that exposure to air pollution leads to a decreased immune response, thus facilitating viral penetration and replication. Viruses may persist in air through complex interactions with particles and gases depending on: 1) chemical composition; 2) electric charges of particles; and 3) meteorological conditions such as relative humidity, ultraviolet (UV) radiation and temperature. In addition, by reducing UV radiation, air pollutants may promote viral persistence in air and reduce vitamin D synthesis. Further epidemiological studies are needed to better estimate the impact of air pollution on COVID-19. In vitro and in vivo studies are also strongly needed, in particular to more precisely explore the particle–virus interaction in air.

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