Health damage from air pollution cost between 0.4% and 6% of annual GDP in the world’s leading cities on the first half of 2020, due to increased risks of chronic illnesses, asthma, work absences, preterm births and many other health impacts. CREA has worked with AirVisual and Greenpeace to release an online tool that tracks the health impacts and economic costs of air pollution in the world’s cities in real time. 

The results reveal that out of the 28 cities included, New Delhi bore the highest cost of air pollution, amounting to 5.8% of its annual GDP. The costs include work absences due to sick leave, number of people suffering from asthma as well as asthma-related trips to the hospital, years of life lost and years lived with the disability, and preterm births. All amounting to a total cost of $3.5 billion for the past six months. 

Cities with the highest cost as a percentage of GDP are cities with the highest pollution levels: New Delhi, Beijing, Mumbai, Shanghai, Jakarta, Guangzhou, Bangkok, Moscow, Hong Kong and Seoul. Other factors include prevalence of other risk factors for chronic diseases and level of health care services.

Figure 1. Top 10 cities with the highest costs of air pollution as a percentage of their GDP. 

Cities with highest costs in dollars per capita tend to be cities with both relatively high pollution levels and income and cost levels: Canberra, Los Angeles, Berlin, Seoul, Tokyo, London, Dubai and Bucharest top the list. 

Figure 2. Cities with the highest costs of air pollution in dollars per capita. 

The results of the tool also highlight the tremendous public health impact and costs from Australia’s catastrophic wildfires: Canberra’s average PM2.5 pollution levels in December were 8 times as high as the city’s average, with the increased PM2.5 exposure expected to result in health costs of $600 million and 260 excess deaths over the next years. As a result, Canberra, usually a much less polluted city, lists the highest in costs per capita among the 28 cities.

Understanding the impacts on Delhi

New Delhi has the highest cost of air pollution, accounting for 5.8% of its GDP. The cost of air pollution has been calculated separately for PM2.5 and NO2, based on the health impacts of each pollutant. In New Delhi, non-communicable diseases and lower respiratory infections have been intensified by PM2.5 and NO2, resulting in deaths, years of life lost and years spent living with the disability. Lower respiratory infections in children have resulted in deaths and in years of life lost. Over 4,000 new cases of asthma in children have been attributed to high levels of NO2 pollution. This, in turn, has increased the number of children suffering from asthma by 16,000. Exposure to PM2.5 has led to well over 15,000 asthma-related emergency room visits for children. The costs of children’s lives lost due to PM2.5 reach $310 million.

The total costs of air pollution in New Delhi amount to $3.5 billion.The figure below shows the division of the costs in percentages according to the air pollutant causing a certain health impairment.Years of life lost, due to high levels of PM2.5, make up for the greatest proportion of costs. This cost comes to about $2.57 billion, or 54.9% of the total costs. 

Figure 3. New Delhi cost percentages per health impact. 

The counter builds on the methodology of CREA report “Quantifying the Economic Costs of Air Pollution from Fossil Fuels”. For that report, we combed through scientific literature for the latest results on health impacts of air pollution, and economic costs of different health conditions that were linked to air pollution in scientific literature. Only exposure-response relationships that were mature enough to already have been used to quantify the total burden of air pollution in peer-reviewed publications were qualified. 

How does air pollution affect the economy?

The different health impacts of air pollution affect the economy in different ways – e.g. kids having asthma means increased costs to the healthcare system, children’s caretakers having to take time off from work to accompany the child to hospital or doctor, and impaired learning results. An adult suffering from disability caused by a stroke, for example, will similarly incur higher healthcare costs and lower economic productivity. 

In addition, a higher risk of death or disability affects people’s well-being; this welfare cost can be measured in money using an approach called willingness-to-pay. We include these different types of cost as far as possible. The details of how we assigned an economic cost to each type of health impact are in the report; they are all based on existing studies assessing those costs. 

The online tool uses air pollutant concentration data from AirVisual’s global database to track air pollution exposure in real time. While most of the health impacts are chronic, resulting from long-term exposure, that exposure is made up of the pollution we breathe in every day. 

Under the hood

To understand how we can link specific health impacts to air pollution, consider this example of a hypothetical city of 1 million people: say the death rate from lung cancer in the city is 100 deaths per year per 100,000 people, so every year about 1,000 people die from lung cancer in that city. The share of these deaths linked to air pollution is assessed based on a risk model developed by the Global Burden of Disease project. Based on the model, if the annual average PM2.5 level is 20ug/m3, the risk of death from lung cancer is 25% higher than for people living in clean air. This means that without air pollution, the death rate from lung cancer would be 80 deaths per 100,000 people, meaning that a total of 200 deaths per year would be avoided if air pollution was brought down below threshold concentration for this impact.

Figure 4. PM2.5 increases the risk of suffering from different diseases.

Scientific research establishing a link between health risks and air pollution is generally based on annual average pollutant levels. Our tracker first projects the health impacts and economic costs of the past year (365 days) of air pollution exposure. We then calculate the extent  of the air pollution exposure that occured over the past year  since the start of the calendar year, and attribute this portion of the impact to the period from the first of January to the present date.

The economic impact of these deaths manifests in different ways: some of the people will still be in working age, meaning that their labor input will be lost. For retired folks,  spending power and demand will be lost. Talented workers will be less willing to move into the city because of the risk of suffering from health consequences. Willingness-to-pay surveys measure the economic costs that people assign to a small additional risk of death or other health impacts, such as the 1:5,000 chance of dying from lung cancer because of air pollution in our hypothetical city.