Air Pollution Social Cost: From National Tendencies to Local Impact

Ari pollution-related deaths in Georgia After 2016

In 2016 several international organizations, including International Energy Agency and World Health Organization published alarming data, according to which, Georgia holds a front position in air pollution-related deaths not only on a regional but on the international level.

Most of the data, published in 2016 was based on the information available right before publishing, while part of it was based on the most comprehensive data available at that time – the 2012 WHO database. Since then, an updated and verified database has become available, which makes it possible to re-evaluate air pollution-related deaths and social burden, as well as observing the long-term dynamics of the country.

The data below provides an overall picture of the extent of the damage air pollution poses to the population of Georgia; how the situation had changed from year to year and how special is the situation in Georgia in the context of region and other countries.

Before discussing the updated database, let’s define how air pollution-related mortality is calculated and what this data might tell us. As a rule, the impact of polluted air on a person’s medical history could only be detected indirectly or on an assumption. The air pollution impact can be fully demonstrated with the help of statistical methods. The correlation between air pollution and damage to human health is revealed in medical statistics through an increase in the occurrence of some diseases, increased mortality and decreased quality of life.

Talking about air pollution-related mortality we refer to the death cases caused by diseases triggered by exposure to polluted air, including cardiovascular and respiratory problems, as well as oncological diseases. As a rule, air pollution is not the only factor, but one of the several factors causing disease. In order to define specifically air pollution impact on any kind of disease occurrence, research is conducted using a multi-component statistical study, which makes it possible to separate the impacts of different factors.

Today, the scientific literature trusts two main models in calculating air pollution-related death – models of the WHO and the Institute of Health Metrics and Evaluation (IHME). These models reinforce each other – despite using different statistical approaches, they come to similar results. For instance, according to WHO air pollution causes 7 million premature deaths worldwide, and according to the IHME, this rate is 6.7 million.

Air pollution is caused by natural, as well as anthropogenic sources. Anthropogenic air pollution is considered to cause the greatest share of pollution-related deaths. According to large-scale research, published in 2019, out of 8,8 million air pollution-related deaths, anthropogenic air pollution is responsible for 5,5 million deaths.[1]

However, excessive mortality is not the only effect of air pollution. It is known, that air pollution is related to the cardiovascular, neurological, hormonal oncological, mental, reproductive system and other health problems. Mortality research is one method to assess the impact of air pollution, as it makes the severity and scale of the problem obvious.

Figure 1 shows the air pollution-related deaths data from 1990 to 2019 years – it shows the total amount of deaths for each year. The graph shows that the general trend is downward. 1990 deaths (8907) are twice as many as deaths in 2019 (4787). Globally this rate through these years remained mostly unchanged. [2]

However, the total number of mortality does not display the full picture, because it is not based on the size of the population. This is especially problematic when the population undergoes significant demographic changes, this was the case for Georgia as well over the given period; hence more useful figure is deaths per 100, 000 people, where the population change factor is taken into account. In order to understand what does the downward trend tells us, it is necessary to break down the mortality rate into components. Discussing the air pollution damage, we should distinguish between ambient and indoor air pollution.

Ambient air pollution is caused by the sources of pollution such as particulate matter, emissions/smoke. Indoor air pollution is caused by emissions from stoves or heaters, cigarette smoke. The quality of ambient and indoor air is related but are different issues as they are affected by different factors and have different outcomes. Therefore, for accuracy, it is important to consider them independently.

Graph 2 shows the mortality data from 190 to 2019 year per 100, 000 people. It also separately shows the ambient and indoor pollution-related deaths.[3]

Breaking down into components of ambient and indoor pollution shows, that the decline of death rate over the last two decades is related to the reduction of indoor air pollution-related mortality. This decrease should be related to the reduction of the use of firewood as a heating source. Using firewood as fuel is declining worldwide.[4]

Regarding ambient air pollution-related deaths, the death rate in 2019 (51 deaths per 100, 000 people) is about the same as ten years ago (54). Despite the data shows a slight reduction compared to 1990-ies, it is negligible, considering the statistical errors.

As it is shown on the graphs, ambient air pollution is responsible for the increasing share of total deaths over the years. And the major responsible factor for this is the high concentrations of particulate matter. It is considered the greatest damage, including mortality is associated with this pollutant. Thus, it is important to separate the damage associated with particulate matter and how it changes over time.

At the same time, mortality is not the only criterion to measure the extent of the impact of air pollution. Another useful data is the amount of Disability-Adjusted Life Years (DALY) lost due to air pollution. This data is essential as it goes beyond just accounting fatal cases and creates a much more complete picture of the impact of air pollution. Hereby, the mortality rate is closely related to the demographic structure of the population – an increase in deaths may be the result of the average older age of the population, rather than a worsened air quality.

Air Pollution and Pandemic: 2020 – 2022 Years

The data provided above is no longer available from 2020 when the COVID pandemic spreads worldwide. The pandemic makes it difficult to calculate and analyze air pollution-related mortality, as COVID-19 causes problems of the respiratory system in the first place. It was said after the first wave of the pandemic, that “chronic respiratory stress” which is caused by long-term exposure to pollution, would increase the risk of disease complications and mortality in polluted areas. “Chronic respiratory stress” is revealed in polluted cities, especially among those people, who work in mining and industrial sectors.

Epidemiological studies have confirmed that “chronic respiratory stress” would make specific groups of people more vulnerable. Regions and occupations, with a high prevalence of respiratory system diseases, appeared to be more vulnerable to COVID-19. Research, conducted in 2020, confirmed, that “as expected, COVID-19 mortality was higher in those areas, where PM2.5 concentrations exceeded the limits. According to the scientists’ report, 15% of global COVID-19 deaths were associated with PM air pollution. In the heavily polluted countries of East Asia, this rate was 27%.[5]

On the other hand, restrictions imposed during COVID-19 made it possible to significantly improve the air quality both in Georgia and Globally. As a result, respiratory illnesses decreased. According to the Finnish “Centre for Research on Energy and Clean Air” (CREA), as a result of restrictions during the pandemic, the concentration of NO2 was reduced by 40% and of particulate matter – by 10%, in Europe. According to their statistical model, this change made it possible to avoid about 10, 000 premature deaths.

In the scale of this article, the most important is the fact that the pandemic has created an exceptional situation in regard of estimating and interpreting air pollution-related mortality – on the one hand, it highlighted the severity of chronic respiratory stress- caused vulnerability to respiratory diseases; while on the other hand, improved air quality reduced mortality rate. However, COVID-19 mortality is not only driven by air quality, but by many other factors as well.

From National Tendencies to Local Impact: What Makes it Difficult to Estimate the Air Pollution Impact in Rustavi

Using statistical methods in the calculation of air pollution-related mortality is associated with significant difficulties – the number of variables to be considered, data quality issues, and nonhomogeneous data interpretation makes it difficult to prove the correlation.

Two types of information is necessary to determine and assess air pollution-related damage: highly accurate, reliable and geographically precise data on air quality, and likewise comprehensive medical database. Behind almost all studies of the effects of pollution is a comparison between a group exposed to polluted air and a group living or working in a relatively less polluted environment. It is possible to compare in terms of time – comparing a less polluted period with a more polluted period – as well as in terms of space – comparing less polluted environment to the more polluted one.

Findings on a national level only help us to see the general picture. Meanwhile, the major impact of air pollution reveals itself on a local level. In Georgia, more than 60% of the population lives in towns, hereby negative impact of air pollution is concentrated in the towns. Accordingly, behind the mortality or illness database stands information on the population of large cities.

As it is said in the special report of the Ombudsman “The exact impact of air pollution on the health of the population is not being assessed in the country according to the parameters recommended by the World Health Organization; the reason of which is the existing system of air quality monitoring, that does not provide a complete picture of air pollution”.[6] The problem is also mentioned in the National Environment and Health Action Plan of Georgia (NEHAP-2) – “existing air quality assessment system does not allow to fully assess the air pollution its health consequences throughout the country in accordance with the WHO recommended parameters”.[7]

Along with improving the air quality monitoring system, it is crucial to upgrade the quality and availability of epidemiological data, which is also an obstacle as of today.[8]

Geographically detailed ecological and epidemiological data would make it possible to determine not only national tendencies but to assess local impacts as well, including conducting quantitative research on air pollution impact in Rustavi, that would answer key questions about the social burden of air pollution: what share of air pollution-related illness is caused by the anthropogenic pollution? What type of morbidity is caused by air pollution in Rustavi and how can it be dealt with? Who is the most vulnerable to air pollution? What would be the most effective measures to reduce the harmful effects of air pollution?

Prospective as well as retrospective epidemiological research would answer these questions. In the first case, a certain group of the population should be selected and observed over the years in regard of health conditions while exposed to polluted air. In the framework of retrospective research, it is possible to model past pollution, measure exposure to it and find possible correlations in the medical history of the study group. Today both types of research are widely used to study the health effects of air pollution, and the choice between them is mostly driven by data availability.

In the case of Rustavi, it would also be relevant to conduct spatial research – in other words, comparing not only in time but also by location. For instance, the fact, that Rustavi is divided into two parts – New and Old Rustavi – creates a “natural experiment”. The prevalence of enterprises on one side of the city makes a statistically good case for studying the effects of air pollution.

Assessing Damage and the Impact Beyond Healthcare

In 2017 the Government of Georgia approved the plan about “measures to reduce ambient air pollution in Tbilisi”, which, among other interventions, includes measures to “assess the impact of air pollution on human health”. As a part of the plan, the National Centre for Disease Control developed indicators to assess the impact of air pollution, including, “acute respiratory disease mortality rate in children aged 0-4 years”; “acute respiratory disease morbidity rate in children aged 0-4 years”, “children aged 0-4 years, who live in households, where coal, firewood or biomass is used as the main source of heating and cooking”; “chronic respiratory disease prevalence in children aged 0-14 years”. In addition, a census of the population, that consumes solid fuel is planned; It is also planned to determine the percentage of people, living in the cities with different concentrations of PM10.

If implemented, the combination of these measures would create the first systemic study of air pollution impact using modern technology. However, it is important the study group to include people of other age groups as well. As it is shown on the graph[9], elder population is the most vulnerable in regard of air pollution-related deaths; and this factor stresses the necessity to include these people in the study.

Moreover, the full social burden, that air pollution imposes on the population is not limited to just damage to health. Air pollution has a negative impact on the various aspects of social, economic and cultural lives, such as academic performance, productivity, real estate prices and etc. Therefore, in order to assess the scale of the social burden of air pollution, it is also important to assess these types of impacts.

The current situation regarding data and information about air pollution health effects is as follows: some databases are available on general tendencies at the national level, however, there is a huge deficit of data and knowledge about local impacts in regard of both health on other types of impacts.

The article was prepared by Giorgi Tsintsadze in cooperation with “Gavigudet” in the framework of USAID Civil Society Engagement Program, funded by the United States Agency for International Development (USAID).

The content of this article is the sole responsibility of the author and do not necessarily reflect the views of USAID, the United States Government, or EWMI.

[1] https://www.pnas.org/doi/10.1073/pnas.1819989116

[2] Global Burden of Disease Collaborative Network. Global Burden of Disease Study 2019 (GBD 2019) Results. Seattle, United States: Institute for Health Metrics and Evaluation (IHME), 2021.

[3] Global Burden of Disease Collaborative Network. Global Burden of Disease Study 2019 (GBD 2019) Results. Seattle, United States: Institute for Health Metrics and Evaluation (IHME), 2021. RISK: HOUSEHOLD AIR POLLUTION FROM SOLID FUELS & AMBIENT PARTICULATE MATTER POLLUTION

[4] Bonjour et al. (2013) – Solid Fuel Use for Household Cooking: Country and Regional Estimates for 1980–2010. Environmental Health Perspectives.

[5] ბეთ გარდინერი. „დაბინძურებული ჰაერის დამღუპველი შედეგი.“ National Geographic. 2021

[6] „უფლება სუფთა ჰაერზე (ატმოსფერული ჰაერის ხარისხი საქართველოში).“ საქართველოს სახალხო დამცველი. 2019

[7] გარემოს ჯანმრთელობის ეროვნული სამოქმედო გეგმა 2018-2022 (NEHAP-2)

[8] „რუსთავი – კორელაცია სასუნთქი სისტემის დაავადებებსა და ჰაერის დაბინძურებას შორის“. ცირა გვასალია. გავიგუდეთ

[9] Global Burden of Disease Collaborative Network. Global Burden of Disease Study 2019 (GBD 2019) Results. Seattle, United States: Institute for Health Metrics and Evaluation (IHME), 2021. Variable calculated by OWID: the sum of [‘Deaths – Cause: All causes – Risk: Ambient particulate matter pollution – Sex: Both – Age: Under 5 (Rate)’, ‘Deaths – Cause: All causes – Risk: Ambient ozone pollution – Sex: Both – Age: Under 5 (Rate)’]