Pollution's Deadly Threat: Can It Kill Everyone?

Air pollution is a global issue that affects the health of humans, animals, and plants, and it can even damage buildings. It consists of chemicals or particles in the air that are released through emissions from factories, cars, planes, aerosol cans, and second-hand cigarette smoke. According to the World Health Organization, air pollution kills about 7 million people annually, contributing to heart and lung diseases, lung cancer, and respiratory infections. It is also linked to an increased risk of some cancers and antibiotic resistance.

While the effects of air pollution are felt worldwide, they disproportionately affect people in low- and middle-income countries, as well as susceptible populations such as those with pre-existing health conditions or those who live in areas with high levels of air pollution. Indoor air pollution, often caused by the burning of substances like kerosene, wood, and coal for heating and cooking, is associated with 3.2 million deaths per year, mainly in Sub-Saharan Africa, the Indian subcontinent, Southeast Asian countries, and Russia. Outdoor air pollution is linked to approximately 4.2 million premature deaths worldwide.

The main sources of outdoor air pollution include the production of electricity, particularly in coal power plants, burning solid fuels for cooking and heating, agriculture, industry, and road transport. Natural sources of air pollution include airborne dust from deserts, smoke from wildfires, sea spray, pollen, and volcanoes.

Addressing air pollution requires a combination of individual, community, and policy-level actions. Reducing the use of fossil fuels and transitioning to clean energy sources is crucial for mitigating the health impacts of air pollution.

Air pollution kills millions each year

Air pollution is a pressing global issue that claims the lives of millions annually. According to various sources and reports, the number of people who die each year from air pollution ranges from 7 million to as high as 10 million. The World Health Organization (WHO) and other health experts have estimated that air pollution is responsible for approximately 9 million premature deaths worldwide each year, accounting for about 16% of all deaths globally. This makes air pollution the single biggest environmental threat to human health.

The impact of air pollution is felt disproportionately by people in low- and middle-income countries, with 92% of pollution-related deaths occurring in these regions. Countries like India, China, Pakistan, Bangladesh, Madagascar, and Kenya are among the most severely affected, with up to one in four deaths attributed to air pollution. However, it is important to note that air pollution is not just a problem in developing nations. Wealthier nations like the United States and those in Europe also struggle with poor air quality, and their citizens are not spared the health consequences.

The primary sources of outdoor air pollution are the burning of fossil fuels, forest fires, waste burning, and other industrial activities. Indoor air pollution, on the other hand, is largely caused by the use of wood, charcoal, coal, and other organic materials for cooking and heating. The harmful pollutants released into the air, such as particulate matter, ozone, nitrogen dioxide, and sulfur dioxide, have severe health impacts. Breathing polluted air increases the risk of heart disease, stroke, lung cancer, respiratory problems, and other non-communicable diseases.

The economic toll of air pollution is also significant. The welfare economic losses associated with pollution-related deaths amount to billions or even trillions of dollars annually, impacting national budgets and hindering economic growth, especially in low- and middle-income countries.

Despite the alarming statistics and the urgent need for action, the response to this crisis has been inadequate. While some countries, like China, have incorporated pollution-control targets into their policies and shown some progress, most nations have done little to address this enormous public health problem. It is crucial that countries prioritize pollution prevention, allocate sufficient funding, establish monitoring systems, and take decisive action to reduce air pollution and protect the health and well-being of their citizens.

It is a global issue

Air pollution is a global issue. According to the World Health Organization (WHO), it is the "single biggest environmental threat to human health". An estimated seven million people die every year from indoor and outdoor air pollution. That's more than died from Covid-19 over the last two years.

Nearly all of the world's population (99%) breath air that is dirtier than the levels recommended by the WHO. Outdoor air pollution is caused by emissions from factories, cars, planes, aerosol cans, and second-hand cigarette smoke. It is most common in large cities where emissions from many different sources are concentrated, and it can be trapped by mountains or tall buildings.

The effects of air pollution are felt most by susceptible and vulnerable populations. Those with pre-existing conditions or genetic predispositions to respiratory or cardiovascular issues are likely to be the hardest hit. Additionally, those who live in poorer areas may have less access to healthcare and less time to stay active and fit, further increasing their risk.

Air pollution does not just affect humans. Animals, plants, and entire ecosystems can suffer from its effects. It can contaminate the surface of bodies of water and soil, killing crops, reducing yields, and killing young trees and other plants. It can also cause acid rain, which damages plants, degrades water quality, and causes buildings and monuments to decay.

While air pollution is a global issue, it does not affect everyone equally. Where people live and how much they earn determine the risks they face from toxic air. Indoor air pollution, for example, is associated with 3.2 million deaths a year, mostly in regions such as Sub-Saharan Africa, the Indian subcontinent, several Southeast Asian countries, and Russia, where many households still use dirtier-burning fuels such as kerosene, wood, or coal for primary heating or cooking.

Outdoor, or ambient, air pollution is associated with 4.2 million premature deaths worldwide, according to the WHO. Last year, the World Bank estimated the global toll of the health damages associated with ambient air pollution to be $8.1 trillion, roughly 6.1% of the global gross domestic product. Once again, the burden of this falls disproportionately on low and middle-income populations.

While there have been some victories in the battle against air pollution, such as the Clean Air Act in the US, which has saved hundreds of thousands of lives, the reality is that the road ahead is not one single path, but a multitude of different paths for different regions that crisscross in unpredictable ways. As the demand for energy grows, experts anticipate a dangerous mix of old and new pollutants.

It affects vulnerable groups the most

While pollution affects everyone, certain groups are more vulnerable than others. According to the US Environmental Protection Agency (EPA), about 15% of the US population, or roughly 46 million Americans, live in rural areas where healthcare access is limited, and residents are more likely to be uninsured. In the US, socially vulnerable groups include communities of colour, low-income groups, certain immigrant groups, and those with limited English proficiency. These groups are more at risk because they may live in locations prone to climate-related health hazards, have higher rates of existing medical conditions, live in areas with poorly maintained infrastructure, and face barriers in accessing healthcare, social services, and nutritious food.

Children are particularly vulnerable to air pollution as their airways are still developing, and they breathe more rapidly and inhale more air relative to their size than adults. Additionally, children have less developed immune systems, making them more susceptible to respiratory infections. Growing up in an environment with high levels of air pollution can affect lung development, increasing the risk of lung disease later in life.

Pregnant individuals and their foetuses are also uniquely susceptible to harm from environmental contaminants, including air pollution. Exposure to air pollution during pregnancy is strongly associated with premature birth, low birth weight, and stillbirth. Additionally, air pollution can increase the risk of hypertensive disorders, intrauterine inflammation, and damage to the placenta, which can disrupt fetal growth and development.

Older adults are at increased risk from air pollution as well. The aging process gradually reduces lung capacity and function, and older immune systems are less effective at protecting the lungs from inhaled contaminants. As a result, older adults are more susceptible to respiratory infections and are more likely to have chronic illnesses that may be exacerbated by air pollution exposure.

People with pre-existing health conditions, such as asthma, COPD, cardiovascular disease, and diabetes, are also more vulnerable to the effects of air pollution. Air pollution can trigger cellular injury and inflammation, putting additional stress on compromised organs and leading to worsening symptoms, increased medication use, and more frequent hospital visits.

People of colour are disproportionately impacted by air pollution due to historical and ongoing systemic racism and discriminatory practices such as redlining and segregation. These practices have restricted mobility options, limited economic and political power, and resulted in communities of colour being concentrated in more polluted areas. Additionally, people of colour are more likely to have chronic conditions that increase their susceptibility to the health impacts of air pollution.

Low-income individuals and communities are also more vulnerable to the effects of pollution. They are more likely to live near sources of pollution and have fewer resources to relocate. Low-income areas often lack safety, green spaces, and access to high-quality food, which can contribute to increased psychosocial distress and chronic stress, making residents more susceptible to pollution-related health effects. Furthermore, low-income individuals have lower rates of health coverage and face barriers in accessing affordable healthcare.

It can cause a range of diseases

Air pollution can cause a range of diseases, affecting almost every organ in the body. The World Health Organization (WHO) has provided evidence of links between exposure to air pollution and type 2 diabetes, obesity, systemic inflammation, Alzheimer's disease, and dementia. The International Agency for Research on Cancer has classified air pollution, particularly fine particulate matter (PM2.5), as a leading cause of cancer.

Short- and long-term exposure to air pollution can lead to a wide range of diseases, including:

• Stroke
• Chronic obstructive pulmonary disease
• Trachea, bronchus, and lung cancers
• Aggravated asthma
• Lower respiratory infections

Additionally, air pollution has been linked to an increased risk of adverse pregnancy outcomes, such as low birth weight and pre-term birth. Research also suggests a potential connection between air pollution and neurological development issues in children, as well as an increased risk of other cancers, diabetes, cognitive impairment, and neurological diseases.

Fine particulate matter (PM2.5) is of particular concern as it can be inhaled deeply into lung tissue and contribute to serious health problems. These particles are 30 times thinner than a human hair and can penetrate deep into the lungs, enter the bloodstream, and travel to various organs, causing systemic damage to tissues and cells. Exposure to PM2.5 has been associated with an increased risk of death.

Other harmful pollutants include carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), and sulphur dioxide (SO2). These pollutants can lead to oxidative stress, inflammation, immunosuppression, and mutagenicity in cells throughout the body.

It is linked to climate change

Air pollution and climate change are directly linked. The burning of fossil fuels, which is responsible for about 80% of the greenhouse gas emissions that drive climate change, is also a major source of air pollutants.

The main cause of CO2 emissions is the extraction and burning of fossil fuels, which is also a significant source of air pollutants. Many air pollutants have direct or indirect climate effects, and some pollutants warm the Earth while others cool it. These short-lived climate-forcing pollutants (SLCPs) include methane, black carbon, ground-level ozone, and sulfate aerosols.

Black carbon, or soot, is formed through the incomplete combustion of fuels. While it only lasts a few days in the atmosphere, it has a warming impact that is 460-1,500 times higher than carbon dioxide. This is due to its ability to absorb solar radiation and convert it into heat, warming its surroundings. Black carbon also reduces the surface albedo of snow and ice crystals, making them susceptible to melting. When embedded in clouds, soot dims the sunlight that reaches the Earth by absorbing it, causing changes in cloud and rainfall patterns, which affect both ecosystems and human livelihoods.

Methane is a greenhouse gas with a lifetime of 12 years. Compared to carbon dioxide, its warming impact is much higher over a 20-year period. Methane serves as the main precursor of ground-level ozone, a major air and climate pollutant. Ground-level ozone is formed by the reaction of sunlight with other air pollutants, and it contributes to global warming and impacts atmospheric circulation, cloud formation, evaporation rates, and precipitation levels, thus contributing to climate change.

By reducing air pollution, we can preserve and protect our climate. To achieve the Paris Agreement goal of limiting warming, rapid reductions in CO2 emissions are necessary, but this alone will not be sufficient. Deep reductions in emissions of non-CO2 climate forcers, particularly the air pollutants methane and black carbon, are also crucial.

The effects of air pollution are felt worldwide, with approximately 7 million premature deaths annually attributed to its effects, about 4 million of which are due to ambient (outdoor) air pollution. Air pollution can cause respiratory illness, leading to missed work and school, and children are especially vulnerable to its impacts.

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