HEALTH authorities and the government must be congratulated on the rapid response to the coronavirus disease 2019 (COVID-19) pandemic, preventing many more deaths in Australia as a result.

Risk factors identified for increased fatality are related to an ageing population, especially to the elderly over 70 years of age, comorbidities and/or co-infection, overcrowded living, overwhelmed health systems, or if people avoided adequate health care.

We also recognised that certain populations other than the elderly are at increased risk of harm from COVID-19 and at increased risk of mortality. These include people with chronic diseases such as diabetes, hypertension, heart and lung disease, obesity and overweight, and people who are immunocompromised and those who have cancer. Aboriginal and Torres Strait Islanders over 50 years of age are also a high risk group.

Smoking has been identified as a risk factor for increased mortality associated with COVID-19. Recent research suggests smokers are more vulnerable to infection and may have a higher risk of serious illness from COVID-19.

So, like smoking, can air pollution create similar effects on the lining of the respiratory tract increasing the risk from COVID-19?

Air pollution

A positive outcome to the lockdown that many people noticed was the air was considerably cleaner worldwide. There was a marked reduction in air pollution and emission levels due to less industry operating and fewer vehicles on the roads. More people were exercising outdoors as our air quality measurements improved; the streets were quieter and safer. Despite the many difficulties we faced during the pandemic, this has been a welcome positive change that we must learn from.

Air pollution was a hot topic during the summer’s bushfires (here and here), leading to increased morbidity and mortality. In recent times, it has also gained much media focus since the publication of several studies that found it may be associated with increased risk of mortality in patients with COVID-19. For example, data from a national study from Harvard University of approximately 3000 counties in the US found that small increments of only 1 μg/m3 in long term exposure to particulate matter less than 2.5 μm in diameter (PM2.5) was associated with an 8% increase in the COVID-19 death rate. Another analysis of COVID-19-related deaths based in Europe found long term exposure of high levels of nitrogen dioxide (NO2) — a pollutant emitted by vehicles — was associated with increased fatality caused by COVID-19. Similar reports and analyses of data found a trend of higher incidence of morbidity and mortality, with mortality rates up to 12% in areas of high pollution in parts of northern Italy compared with approximately 4.5% in the rest of the country. Sources of PM2.5 and NO2 include fossil fuel combustion from motor vehicle exhaust, industry and coal-fired power stations.

In general, air pollution is a known risk factor for a number of diseases and is associated with increased risk of mortality and chronic diseases, such as heart and lung disease, and can increase the risk of lung infections, pneumonia and hospitalisations even from exposure at low doses below current national standards. For example, short term exposure to air pollutant PM2.5 leads to increases in health care use due to lower respiratory tract infections in children and adults in urban environments. Air pollution can increase the risk of inflammation of the lungs, making them more susceptible to harm to diseases such as COVID-19.

More research is required to validate if air pollution is a contributor to increased risk of infection and mortality. There are likely to be other confounding factors contributing to these findings also.

Lessons learned from the COVID-19 pandemic

We have learned many lessons from this pandemic, and we will likely be better prepared for any future pandemics. Clearly, improved lifestyle choices such as avoiding smoking, reducing obesity, and increasing appropriate sun exposure to help address risk factors of infections are major key public health messages.

Whether air pollution is or isn’t a significant modifiable contributor to mortality associated with COVID-19 deaths, the studies and the improvement of air quality during the pandemic do remind us why we should continue to urgently further research, tackle and tighten air pollution standards in Australia and the rest of the world. The pandemic gave us a welcoming glimpse of breathing clean air, making exercise outdoors safer. Many studies have demonstrated exposure to air pollution can lead to a number of adverse health effects, including susceptibility to infections, respiratory and cardiovascular disease, which may subsequently increase vulnerability to COVID-19.

What next?

After the pandemic, will we return to the way things were or will we learn more about our relationship with our planet? What public health messages learned during the COVID-19 pandemic can we provide our community, for example, during the influenza season? What prevention strategies can we use to help educate the community about adaptation responses to infections and pandemics in the future?

In 2019, peak medical bodies called on authorities to strengthen air pollution standards in Australia as air pollution is a modifiable risk factor for increased morbidity and mortality. In line with international studies, Australian research shows there is no safe level of air pollutants even well below the threshold standards. Consultation has now closed, but the decision for the tightening of air pollution standards is likely to occur in the very near future. Australia’s current population in 2020 is about 25.43 million people. It is projected to reach 30 million people by 2033. As our population grows, air pollution from more vehicles on the roads and consequent emissions will be a constant challenge to us all. The pressure on the federal government to tighten air standards should continue so we can achieve cleaner air as we experienced during the COVID-19 pandemic.

The challenge will be after COVID-19 restrictions are lifted, with the return of air pollution from emissions such as vehicle and industry and the ongoing health impacts it will have on humans.

Associate Professor Vicki Kotsirilos AM is a Melbourne GP, and a member of Doctors of Environment Australia.


The statements or opinions expressed in this article reflect the views of the authors and do not represent the official policy of the AMA, the MJA or InSight+ unless so stated.

17 thoughts on “COVID-19 and beyond: impact of air pollution

  1. Anonymous says:

    I would like to say its very important to know about how air pollution grown up and how should we prevent. There are many risk factor vehicles, nitrogen dioxide, some chemical industries. We can’t stop all things but we can less use our things. Like we have to go some place we can take walk or we can take bicycle ride. In chemical industries polluted air is affected their factory’s people like disease related to respiratory system, in factory polluted air go through the chimney, they make air less polluetd. Several countries has air pollution and their consequences is so dangerous. In recently global warming like several factors affect the air pollution. We need to bring awareness against the air pollution and how can we prevention. In worldwide so many people dying during air pollution.

  2. Dan Ewald says:

    indeed, estimated more deaths fro power station PM2.5 and NO than there is from road accidents. How much do we spend of safer roads?

  3. A/Professor Vicki Kotsirilos AM says:

    Thank you for your positive comments and support.
    This paper published in the NEJM just prior to my article is relevant and aligned with our concerns that there is no safe level of air pollutants and harm occurs even below current accepted Government threshold levels. See link:

  4. Clare Walter says:

    Nice article Vicki. Your points are so valid and timely as the post COVID traffic ramps up. The mortality and morbidity related to outdoor air pollution in Australia exceeds that of passive smoking (GBD, 2017), it’s time vehicle emissions, wood-heaters and the use of unfiltered power-stations was considered in the same light as passive smoking. Internationally, some cities have made huge strides in adopting measuresaimed at continuing their enjoyment of clean air post COVID. For our healths sake, Australia should follow suit.

  5. Ruth Gawler says:

    Thanks Vicki. Great that you are addressing this important issue and writing about the reality of the situation. Let’s hope this is part of how we create cleaner air for ourselves and all the others on earth who depend on it. Well done!

  6. Magdalena Simonis says:

    Great article Vicki. Very sensible and balanced. One needs to ask, why is the economy treated more like a living thing than the planet? Why do we understand ‘consumers’ much better than communities? Exploring these questions might link to how we change attitudes and policy.

  7. Jenny Altermatt says:

    Wonderful article dear Vicki alerting us all to the need for robust dialogue, acceptance of the irrefutable evidence of the prescient dangers of air pollution, and the need for impartial discussion about legislating solutions. Well done!

  8. Graeme McLeay says:

    We have waited too long for sensible policies to reduce transport pollution. The health problems were known early in this century and all the studies since point to the urgent need to reduce vehicle pollution. The Ministerial Forum on Vehicular Emissions was established in 2015 and has done nothing substantive to reduce these emissions beyond tinkering slightly with petrol aromatics (2022) and sulphur (2027). Meanwhile we go on building more and bigger roads, promoting more car use and importing dirty and inefficient vehicles. Simple steps such as mandating Euro6 standards for new cars and a mandated energy efficiency target (105 gm CO2/km), anti-idling laws, and electrifying all transport are on hold.

  9. Nilanga Aki Banadara says:

    Thank you for sharing timely important perspectives and it is utmost important that we cease this golden opportunity to promote tobacco free life styles of our younger generation. The physician’s urgent task is to assist these vulnerable populations in this uncertain time by facilitating tobacco cessation efforts- offering appropriate and evidence based therapies (NRT, Bupropion, Varenicline) and referral to behavioral counseling. Further, health care community also could advocate for sensible and common sense based tobacco control policies such as e-cigarettes be strictly regulated as a pharmaceutical product, banning or limiting flavored tobacco products, extending existing tobacco marketing restrictions to e-cigarettes, and strictly restricting the sale of e-cigarettes to minors (including the online sales as well). Primary care settings in general, offer a potential “teachable moment” because patients may have perceptions of vulnerability about their health, regardless of the reason for the visit, and therefore may be particularly receptive to screening, counseling, and brief intervention stress that the context offers an important ‘window of opportunity’ to provide services to those with nicotine related problems who might otherwise never receive any form of assessment, referral or early intervention.

  10. Bec pogson says:

    Great article. So many things can be done (with the political will) to improve our air quality.

  11. Jessica Kneebone says:

    An excellent article which highlights the interdependence of health and the environments we live in.

  12. Eugenie says:

    Great Article

  13. Richard Yin says:

    air pollution is an important health issue that requires our ongoing attention. We need tighter standards. Thanks for the article

  14. Dr Nicole Sleeman says:

    Great article Vicki. We are beginning to wake up to the reality that human health is intrinsically related to the environment within which we live. Air quality and the health impacts of air pollution should be on the radar of every health professional. The entire health sector should be lobbying for better air pollution standards, in line with the science. Thank you.

  15. Tom Bat says:

    First thing is to ban sales of wood fired heating and cooking appliances in all urban areas

  16. David King says:

    Excellent and balanced overview of air pollution and health as it relates to our recovery from pandemic lockdown.

  17. Leanne Rowe says:

    Food for thought Vicki on what each of us can do to reduce air pollution. We have seen a dramatic improvement and cleaner air in our cities during the lockdown. What can we do to preserve this beyond the pandemic?

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