We present you a new Belgrade Open School publication: Air pollution and "COVID-19". The topic of this study is the harmful impact of air pollution on population health, as well as the analysis of scientific research, published worldwide, on the relationship between exposure of the population to air pollution and the rate of COVID-19. The author of the publication is Mr. Srdjan Kukolj, an expert in the field of environmental protection and public health.

The publication was created within the project "Air Quality, Public Health and COVID19: Research of Correlations between Air Pollution and COVID-19 in Serbia", which the Belgrade Open School is implementing with the support of the British Embassy in Belgrade.

You can download the complete text of the publication HERE (Serbian version only)

Some of the basic conclusions of the analysis are:

A new coronavirus (SARS-CoV-2) determined the outbreak of pneumonia in China (Wuhan, Hubei province) in December 2019, called COVID-19 disease. The scientific community has come together to implement interventions designed to stop the spread of SARS-CoV-2 globally. However, the Director-General of the World Health Organization announced on March 11, 2020, that COVID-19 could be characterized as a pandemic. SARS-CoV-2 is primarily transmitted by persons in close contact (approximately 2 m), aerosol droplets of airways smaller than 5 μm in diameter (https://www.Who.int/). The indoor environment can be especially dangerous due to reduced ventilation, lack of ultraviolet light that quickly inactivates the virus and therefore can become less dilute than in outdoor environments. It is also known how the virus can survive and be infectious in aerosols for hours and on the surface for up to several days. Apart from causality, it is not clear whether certain demographic categories of the population are vulnerable to SARS-CoV-2 infection. Based on recent reports, males, older age, and accompanying morbidities appear to be associated with death and serious illness. Furthermore, COVID-19 appears to be associated with an increasing rate of thromboembolic events in hospitalized patients. Mechanisms of social and economic interactions should be further involved in the diffuse dynamics of COVID-19 in different parts of the world or the same country, such as living conditions, health-related behaviors.

Polluted air increases the rate of hospitalizations and visits of the health emergency services, further burdening the health care system during COVID-19.

Air pollution has been identified as the biggest cause of disease and premature death in the environment in the world. Scientific evidence shows that short-term and long-term exposure to ambient (outdoor) air pollutants is associated with harmful health outcomes, such as higher mortality rates, higher hospital admissions, and increased ambulance visits.

Polluted air, even when slightly above the limits recommended by the World Health Organization, has pronounced harmful consequences on the occurrence of asthma, bronchitis, pneumonia, and chronic obstructive pulmonary disease, where bacteria and viruses are the most accepted causes that damage the stability of the respiratory system and worsen the infection. Furthermore, air pollution is an aggravating factor for infectious diseases caused by some viral infections, such as influenza A and B, parainfluenza virus type 3, pneumonia, and influenza type diseases. Polluted air increases the rate of hospitalization and the number of visits to emergency services.

Evidence that COVID-19 could be transmitted by PM particles is not reliable.

Several authors suggest that ambient (outdoor) air pollution, which is the result of a combination of factors such as meteorological data, degree of industrialization, and regional topography, could act both as a vector of infection and as a factor in worsening the severity of COVID-19. This association is strengthened by the results of numerous studies initiated around the world and summarized in this review.

Most of the studies reviewed support that chronicle exposure to polluted air could make people susceptible to COVID-19 disease, leading to widespread spread and mortality from COVID-19. However, as Bontempi suggests, the potential outcome of the virus exposure in the air due to the PM10 particles remains unclear.

Diseases that exposure to polluted air causes also pose an increased risk of a severe outcome of COVID-19.

Air pollution increases the risk of many diseases such as chronic obstructive pulmonary disease, asthma, heart disease, cancer, diabetes, and many others. Exactly the same diseases pose an increased risk of a severe outcome of COVID-19.

Reducing air pollution in outdoor and indoor spaces is an important public health measure aimed at improving the health of all, and especially the most vulnerable citizens.

It is generally known that an important public health measure is the reduction of outdoor and indoor air pollution. These measures adopted at the level of cities, municipalities, and the state can have a significant impact on the health of the population almost immediately, and the benefits and savings can far outweigh the costs. Certainly, the urgent health situation currently facing the world emphasizes that environmental research is a fundamental reference point for discoveries about infectious diseases and how to allocate natural, health, social, economic, and all other resources to accelerate actions aimed at implementing environmental policies leading to reducing air pollution and developing new interventions in urban planning.

The number of evidence and scientific studies on air pollution and COVID-19 is growing, but the limitations of these studies should be taken into account.

In this review of the currently available evidence, most studies support a link between air pollution and COVID-19. But it is also important to note that there are multiple limitations: a relatively small number of existing papers, a large variety of methodologies used. Authors who first investigated this correlation, although with great effort and speed of analysis dictated by the global crisis, sometimes do not include all confounding factors such as urbanization rate, availability of medical resources, population size, weather, lifestyles, sociodemographic and socioeconomic variables, etc. In addition, to date, data on the incidence of COVID-19 have been underestimated in all countries, and to a lesser extent on mortality. For this reason, the cases covered by the considered studies cannot be considered final. More studies are needed to better clarify the role of air pollution in light of the COVID-19 pandemic, especially studies that take into account the impacts of multiple pollutants or multidisciplinary studies, to strengthen scientific evidence and support solid conclusions useful for implementing pandemic plans for adequate prevention of new health emergencies.

Correlation is not causality: we cannot say that there is a causal link between polluted air and COVID-19.

Several significant studies show an association between high levels of air pollution (various pollutants) and death from COVID-19. But, it is important to point out that a positive correlation is a priori expected because air pollution is correlated with a high population density, and thus with a high number of deaths in the case of COVID-19. Taking into account many confusing factors, appropriate epidemiological studies are needed to demonstrate that air pollution contributes to the risk of death from COVID-19. Such scientific works are still in progress and, still, we cannot speak with certainty that there is a causal link between polluted air and COVID-19.

Photo source: Belgrad Open School