Air Pollution: What, Why, Who, How And When?

Air pollution is a pressing issue that poses significant risks to human health and the environment. It refers to the contamination of indoor or outdoor environments by solid and liquid particles, certain gases, or biological agents that alter the natural composition of the atmosphere. The primary sources of air pollution include mobile sources, such as automobiles, and stationary sources like power plants. These sources release pollutants such as particulate matter, carbon monoxide, ozone, nitrogen dioxide, and sulfur dioxide, which have detrimental effects on human health, leading to respiratory issues, heart diseases, lung cancer, and even premature deaths. The impact of air pollution extends beyond human health, as it is closely linked to climate change and ecosystems. Addressing air pollution requires collective efforts, including interventions in energy, transport, housing, and urban development sectors, as well as individual actions like reducing vehicle emissions, improving waste management, and adopting cleaner energy sources. Understanding the causes, consequences, and potential solutions to air pollution is crucial for mitigating its harmful effects and ensuring a sustainable future for all.

What

Air pollution is defined as the contamination of the indoor or outdoor environment by any chemical, physical, or biological agent that modifies the natural characteristics of the atmosphere. It consists of chemicals or particles in the air that can harm the health of humans, animals, and plants. It can even damage buildings.

Pollutants in the air can take the form of gases, solid particles, or liquid droplets. They are released into the air through the combustion of fossil fuels, such as coal, natural gas, and oil. This includes driving cars on gasoline, heating homes with oil, and running power plants on fracked gas. When fossil fuels are burned, harmful chemicals and gases are released into the air, contributing to air pollution.

Some of the major outdoor pollution sources include residential energy for cooking and heating, vehicles, power generation, agriculture/waste incineration, and industry. For example, vehicle emissions, fuel oils, and natural gas used for heating homes are primary sources of human-made air pollution. Additionally, by-products of manufacturing and power generation, particularly coal-fueled power plants, and fumes from chemical production contribute to air pollution.

Particulate matter (PM) is a significant component of air pollution. It refers to tiny particles of chemicals, soil, smoke, dust, or allergens that are carried in the air. Fine particulate matter (PM 2.5) is of particular concern as it can be inhaled deeply into the lungs, contributing to serious health problems.

Air pollution has severe health impacts. It is a major environmental health hazard, causing more than 6.5 million deaths each year globally, a number that has been increasing. According to the World Health Organization (WHO), indoor and outdoor air pollution is responsible for nearly seven million deaths annually worldwide. Ambient (outdoor) air pollution in both cities and rural areas contributes to fine particulate matter, leading to strokes, heart diseases, lung cancer, and acute and chronic respiratory diseases.

In summary, air pollution consists of harmful chemicals and particles in the air, primarily from the combustion of fossil fuels and various industrial processes. It poses a significant threat to human health, causing millions of premature deaths annually and contributing to various diseases.

Where

Air pollution is caused by a variety of sources, both human-made and natural. Human-made sources of air pollution are called anthropogenic sources. The burning of fossil fuels for energy production, industry, construction, transportation, and heating is a major contributor to air pollution. Vehicles, airplanes, power plants, and factories release pollutants into the atmosphere through the combustion of fossil fuels such as coal, natural gas, oil, and gasoline.

In addition to the burning of fossil fuels, there are other human-made sources of air pollution. These include residential energy use for cooking and heating, waste incineration, agriculture, and industrial processes such as oil and gas development. Household combustion devices, such as the use of biomass (wood) for cooking and heating, also contribute to indoor air pollution. Cigarette and e-cigarette smoke, as well as secondhand smoke, are considered forms of indoor air pollution.

Air pollution is often concentrated in large cities, where emissions from multiple sources are present. Mountains or tall buildings in and around cities can prevent the dispersion of air pollutants, leading to the formation of smog. Smog, a combination of smoke and fog, is a visible form of air pollution that reduces visibility and can have negative health impacts.

Natural sources of air pollution include wildfires, dust storms, volcanic eruptions, and windblown sand or dust. Wildfires, which have become more frequent due to global warming, release hazardous smoke into the atmosphere. Volcanic activity can emit ash and gases that contribute to air pollution. Dust storms and windblown dust are also natural sources that can impact air quality.

It is important to note that the impact of air pollution is not evenly distributed. Historically, polluting facilities and highways have been sited in or near low-income neighbourhoods and communities of colour, resulting in disproportionate exposure to the negative effects of pollution for the residents of these areas.

Who

Air pollution is a pressing global issue that poses significant risks to human health and the environment. The World Health Organization (WHO) plays a pivotal role in addressing this challenge.

The WHO has developed the Global Air Quality Guidelines (AQG), which offer comprehensive guidance on thresholds and limits for various air pollutants that pose health risks. These guidelines are meticulously crafted through a transparent, evidence-based process and provide interim targets to facilitate a gradual reduction in pollutant concentrations. For instance, achieving the first interim target is projected to save 300,000 lives annually. The AQG also offers practical recommendations for managing specific types of particulate matter, such as black carbon and ultrafine particles.

In addition to setting standards, the WHO actively supports its member states by providing technical assistance and authoritative advice on health issues related to air pollution. This includes monitoring and reporting on global trends and the effectiveness of interventions. The WHO has also implemented a strategy to raise awareness about the risks of air pollution and promote solutions to mitigate exposure risks. Their efforts extend to digital outreach and partnerships with various stakeholders, including health and environment ministries and city governments.

Furthermore, the WHO advocates for policies and investments that address key sources of air pollution. They promote sustainable land use, cleaner household energy and transport options, energy-efficient housing, improved waste management, and the adoption of renewable power sources. These initiatives not only reduce air pollution but also contribute to mitigating climate change and improving overall health outcomes.

The WHO's efforts are instrumental in guiding global actions to tackle air pollution and protect the health and well-being of people worldwide, especially those in low- and middle-income countries who are often disproportionately affected by this issue.

Why

Air pollution is a pressing issue that poses significant risks to human health and the planet. It refers to the contamination of the indoor or outdoor environment by any chemical, physical, or biological agent that modifies the natural characteristics of the atmosphere. This contamination is caused by the release of pollutants, which are detrimental to human health and the environment.

One of the primary causes of air pollution is the combustion of fossil fuels, such as coal, natural gas, and oil. This includes activities such as driving cars on gasoline, heating homes with oil, and running power plants on fracked gas. When these fossil fuels are burned, harmful chemicals and gases are released into the air. This has been a significant issue since the Industrial Revolution, when the use of coal for heating, factory power, and engines became more prevalent. Today, vehicle emissions, fuel oils, and natural gases used for heating continue to be major contributors to air pollution.

In addition to fossil fuels, industrial processes and power generation contribute to air pollution. This includes the manufacturing of iron, steel, and rubber products, as well as coal-fueled power plants, which release harmful substances into the air. The by-products of chemical production and fumes can also be detrimental. These human-made sources of pollution are called anthropogenic sources.

Air pollution also has natural sources, such as smoke from wildfires, ash and gases from volcanic eruptions, and gases released from decomposing organic matter in soils. However, it is important to note that human activities, such as deforestation and climate change, can contribute to the frequency and intensity of wildfires, which in turn affects air quality.

The effects of air pollution on human health are significant. It is associated with approximately 6.7 to 8 million premature deaths annually worldwide. The pollutants can cause direct harm through toxic gases, which particularly affect individuals with existing respiratory conditions. Additionally, pollutants can form particulate matter, which consists of smaller particles that can be inhaled deeply into the lungs, leading to serious health issues. These particles can also contribute to the formation of ground-level ozone, commonly known as smog, which can irritate the eyes, throat, and lungs. The health impacts vary depending on the type of pollutant, the length and level of exposure, and individual health risks.

How

Air pollution is caused by the release of pollutants into the air, which are detrimental to human health and the planet. The burning of fossil fuels, such as coal, natural gas, and oil, is a major source of air pollution. This includes driving cars, heating homes, and running power plants.

Household combustion devices, motor vehicles, industrial facilities, and forest fires are also common sources of air pollution. Pollutants of major concern include particulate matter, carbon monoxide, ozone, nitrogen dioxide, and sulfur dioxide.

Particulate matter is composed of chemicals such as sulfates, nitrates, carbon, or mineral dust. The smaller the particles, the worse they can be for human health, as they can enter our lungs and airways and even our blood. Fine particulate matter, or PM 2.5, is 30 times thinner than a human hair and can cause serious health problems.

Ozone is formed when pollutants react with sunlight. Ground-level ozone, or smog, can irritate the eyes and throat and damage the lungs. It is especially harmful to children, senior citizens, and people who work or exercise outdoors.

To reduce air pollution, policies and investments that support sustainable land use, cleaner household energy, cleaner transport, energy-efficient homes, improved waste management, and renewable power sources are necessary. Access to clean household energy solutions for cooking, heating, and lighting can significantly reduce ambient air pollution.

Frequently asked questions