Air Pollution's Worst Victims: A Global Health Crisis

Air pollution is a pressing global issue, with over 99% of people living in areas with unsafe air. The World Health Organization (WHO) reports that air pollution causes 7 million premature deaths every year, with non-communicable diseases accounting for 72% of these. The primary sources of air pollution are fossil-fuel-powered vehicles, coal- or oil-burning power plants, and factories. While many countries are more polluted than others, it is important to note that the most polluted countries are not always the biggest polluters. Some of the least polluted countries are responsible for detrimental air quality in other places. According to various sources, including IQAir and the University of Chicago, the following countries are among the most affected by air pollution: Bangladesh, Pakistan, India, Tajikistan, Burkina Faso, Iraq, United Arab Emirates, Chad, and the Democratic Republic of the Congo.

Bangladesh's air pollution crisis

Bangladesh has been ranked as the world's most polluted country, with its capital, Dhaka, taking the 21st spot for most polluted city in 2019. The country's air quality has seen a slight improvement since then, but it still ranks among the worst globally. The annual average levels of ambient fine particulate matter (PM2.5) range from 60 to 100 µg/m³ across the country and 90 to 100 µg/m³ in Dhaka, far above the World Health Organization's Air Quality Guideline of 5 µg/m³. These levels can even rise up to two or three times higher during the dry months from November to March.

The primary sources of air pollution in Bangladesh are its brick-making industry, vehicle emissions, and industrial emissions. The country's brickmaking industry employs one million people and creates 23 billion bricks annually, with Dhaka being famous for its high output. The burning of materials such as coal and wood in brick kilns releases toxic black soot into the atmosphere. Additionally, the country's growing population has led to an increase in cars, larger demand for homes, and a boom in all industries, contributing to higher vehicle emissions.

The health effects of breathing polluted air in Bangladesh are significant. Exposure to high levels of air pollution can cause irritation to mucous membranes, increase the risk of chest infections, and lead to respiratory conditions such as influenza and pneumonia. The fine particulate matter (PM2.5) in the air can cause rapid aging of the lungs, reduce lung capacity, and increase the risk of lung cancer. It can also enter the bloodstream and cause damage to other organs, including the liver and kidneys. Young children exposed to high levels of pollution may experience developmental problems and cognitive impairments, and pregnant women are also at higher risk of miscarriage, stillbirth, and giving birth to underweight or premature babies.

To address the air pollution crisis, Bangladesh has taken several steps, including the approval of the National Air Quality Management Plan (NAQMP) 2024-2030, which aims to strengthen air quality governance, improve monitoring and enforcement mechanisms, and reduce emissions from major sources. The government has also launched a real-time air quality index and is working towards promoting clean cooking, the use of cleaner fuels, and the adoption of cleaner and energy-efficient technologies. However, the report by the World Bank highlights the need for coordinated transboundary actions with neighboring countries, as air pollution does not respect national boundaries.

Desert dust in Chad

Chad is currently the most polluted country in the world, according to the latest data. The country's air quality crisis is driven by several factors, including desert dust, vehicle emissions, and biomass burning. Chad's capital, N'Djamena, is often blanketed by dust storms, and the country's increasing reliance on biomass as its primary energy source for cooking and heating is raising indoor pollution levels. This has dire health implications, particularly for vulnerable groups such as children and women.

Desert dust is a significant contributor to Chad's air pollution problem. The Bodélé Depression, located in northern Chad, is the lowest point in the country and a major source of dust storms. Strong winds frequently whip up dust as they funnel through a break in the Tibesti and Ennedi mountain ranges, causing dust storms that cloud the skies over the ancient lakebed for approximately 100 days each year.

The dust from Bodélé is of particular interest to scientists due to its high content of diatoms, microscopic organisms that are rich in phosphorus, an essential nutrient for plant growth. For many years, it was believed that the dust from Bodélé fertilized the nutrient-limited soils of the Amazon rainforest. However, recent research suggests that much of the dust settles over Africa or is washed out of the atmosphere by rain before reaching South America.

The short-term health effects of desert dust can vary depending on the region. A harmonized way of evaluating these health effects is necessary to compare results from different regions. While the long-term health effects of desert dust are still being studied, it is clear that air pollution, including that caused by desert dust, has a significant impact on human health. According to the World Health Organization, air pollution causes approximately 7 million premature deaths annually, and 91-99% of the world's population lives in places where air quality exceeds the recommended guidelines.

China's mega-cities smog

China's rapid economic growth has been accompanied by an expansion of the urban area population and the emergence of several mega-cities since the 1990s. This expansion has resulted in tremendous increases in energy consumption, emissions of air pollutants, and the number of poor air quality days in mega-cities and their immediate vicinities. Air pollution has become one of the top environmental concerns in China. Beijing, Shanghai, and the Pearl River Delta region, including Guangzhou, Shenzhen, and Hong Kong, are the most economically vibrant regions in China, accounting for about 20% of the country's total GDP in 2005. They are also areas where many air pollution studies have been conducted.

Air pollution in China is mainly caused by the combustion of fossil fuels, such as coal, and vehicle emissions. The main sources of air pollution in Chinese mega-cities are coal combustion for heating, combustion of fossil fuels from vehicles, and industrial fumes. The six major air pollutants in China are fine particulate matter (PM2.5), inhalable particulate matter (PM10), ozone (O3), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO).

During the initial phase of the COVID-19 outbreak, there was a decrease in air pollution levels in some Chinese mega-cities due to reduced anthropogenic activities. Indicators of traffic pollution, particularly NO2, were significantly lower during the outbreak in all cities studied. Particulate matter pollution varied, with some cities observing lower concentrations and others higher concentrations during this period.

Beijing, Shanghai, and the Pearl River Delta region have well-established networks of air quality monitoring stations, and hundreds of research reports on air pollution have been published. The number of publications on air pollution in Chinese mega-cities has been growing rapidly, with a particular focus on Beijing, Shanghai, and the Pearl River Delta region.

While air quality has improved in most Chinese cities despite the rapid economic growth, particulate concentrations in most cities are still far above the World Health Organization's Air Quality Guidelines. The challenge of air pollution in mega-cities will continue to be a top environmental concern in China in the coming years.

US air quality under Trump

Air pollution is a significant problem worldwide, causing over 4.5 million premature deaths in 2019, according to The Lancet. It is a particular issue in emerging and developing countries, where environmental standards are often not met. The World Health Organization (WHO) has set a recommended limit of 5 micrograms per cubic meter, but 91-99% of the world's population lives in areas that exceed this guideline.

In the United States, the Environmental Protection Agency (EPA) measures five major pollutants, regulated by the Clean Air Act. These are:

• Particle pollution (including PM2.5 and PM10)
• Ozone pollution
• Nitrogen dioxide
• Sulfur dioxide
• Carbon monoxide

During the Trump Administration, the EPA claimed that air quality in the United States had improved. In a 2020 statement, EPA Administrator Andrew Wheeler said:

> "Americans are breathing the cleanest air since 1970. Criteria air pollutant emissions under President Trump dropped 7 percent since 2017. This clean air progress proves that when EPA focuses on its core mission and works collaboratively with states, we can achieve world-leading emissions reductions to the benefit of our nation, its citizens, and the environment."

Between 2017 and 2019, the Trump Administration saw reductions in several key pollutants:

• Nitrogen oxide decreased by 14%
• PM 2.5 decreased by 4%
• Sulfur dioxide decreased by 35%
• Carbon monoxide decreased by 8%
• Volatile Organic Compounds decreased by 5%

However, it is important to note that the EPA under Trump also weakened or rolled back numerous environmental regulations. The administration took 74 actions to weaken environmental protection, according to Brookings. These rollbacks were intended to boost fossil fuel production and use, and included:

• Replacing the Clean Power Plan with a weaker regulation
• Revoking California's ability to set its own fuel economy rules
• Weakening rules limiting methane emissions from oil and gas production on public lands
• Lifting bans on oil and gas exploration in protected areas, such as the Arctic National Wildlife Refuge

Trump also vowed to cut ten old regulations for every new one implemented and cut 100 environmental regulations during his first term. These actions and the resulting increase in fossil fuel production have likely had a negative impact on air quality, despite the EPA's claims of improvement.

Saudi Arabia's toxic air

Saudi Arabia's air quality is considered unsafe, with an annual average concentration of PM2.5 that far exceeds the World Health Organisation's (WHO) recommended maximum of 10 µg/m3. In 2017, the annual exposure to ambient particulate matter in the population-weighted mean PM2.5 in Saudi Arabia was 87.9 μg/m3, and this figure is thought to have risen since.

The main contributors to this poor air quality are emissions from vehicles, industry, and natural dust storms. The latter occurs during spring and can last from March to May.

The consequences of this toxic air are dire. Air pollution is one of the top 10 global health risk factors and has been associated with premature mortality, cardiovascular disease, cerebrovascular disease, respiratory disease, and metabolic disease. In Saudi Arabia, ambient particulate matter is the fifth health risk factor, contributing to 9% of total mortality. In 2017, 8,536 deaths were attributed to air pollution, with 240,966 years of life lost (YLL) and 74,234 years lived with disability (YLD) due to PM2.5.

The problem is particularly acute in the city of Dammam, where air pollution is a severe problem. The city of Riyadh has attempted to address this issue by investing in its public service network, with the Riyadh Metro project set to become operational in 2020/21, and environmentally-friendly buses planned for the city centre. However, the country's reliance on oil and urban activities continue to be the main drivers of air pollution.

To improve air quality, Saudi Arabia is considering renewable energy sources such as solar, wind, and hydroelectricity. The country is ranked sixth in the world for its solar energy potential, and Saudi Aramco has plans to develop a solar energy sector to produce 41 GW of renewable energy. Additionally, the country has signed agreements to incorporate 400 MW of wind-generated power into its grid, with the Middle East's largest wind farm under construction in Dumat Al-Jandal. These initiatives are expected to reduce carbon emissions and encourage the use of renewable energy in the country.

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