Air Pollution: Understanding The Invisible Danger

Air pollution is a significant environmental health hazard that affects both indoor and outdoor environments. It refers to the presence of harmful substances in the air, such as gases, solid and liquid particles, and chemicals, which can have detrimental effects on human health, other living beings, and the planet. These pollutants are released into the air through various human activities and natural sources, impacting the natural characteristics of the atmosphere. The contamination of the air by these pollutants has led to severe health risks and environmental concerns, making it a pressing issue that requires global attention and mitigation efforts.

Health impact: respiratory issues, cancer, and early death

Air pollution is a mix of hazardous substances from human-made and natural sources. It is a major threat to global health, causing more than 6.5 million deaths each year, according to one source, or 7 million, according to another. WHO data shows that 99% of the global population breathes air that exceeds its guideline limits and contains high levels of pollutants.

Respiratory Issues

Air pollution exposure is associated with oxidative stress and inflammation in human cells, which may lay the foundation for chronic diseases. It can also cause acute and chronic cardiopulmonary mortality and all-cause mortality. Research has linked exposure to fine particle pollution to a wide array of serious health effects at every stage of life.

Fine particulate matter (PM 2.5) can be inhaled deeply into lung tissue and contribute to serious health problems. It accounts for most health effects due to air pollution in the US. Particles in air pollution can be smaller than 1/30th the diameter of a human hair, and when inhaled, they are small enough to get past the body's natural defences.

There is evidence that both the development of asthma and its exacerbation can be associated with particle pollution exposure. Children with asthma seem to be more affected by particle pollution than adults with asthma, possibly due to behavioural factors such as increased exercise and time outdoors. Children from low-income families are also more likely to be living near high-density traffic or industrial sources of particle pollution.

Cancer

In 2013, the International Agency for Research on Cancer of the World Health Organization (WHO) classified air pollution as a human carcinogen. Since then, there has been a dramatic increase in the number of epidemiological studies that have examined the relationship between chronic particle pollution exposure and lung cancer incidence and mortality. Exposure to the air pollutant PM2.5 is associated with an increased risk of death, with one study finding that exposure to PM2.5 from coal was associated with a mortality risk that was twice as high as the risk from exposure.

Early Death

Air pollution is the ninth leading risk factor for mortality, and outdoor air pollution alone is responsible for 3.2 million deaths each year. Exposure to particle pollution has been consistently linked to an increased risk of premature death, with one study finding a 6-8% increase in the risk of all-cause mortality for every 10µg/m3 increase in the annual average PM2.5. Premature deaths from breathing particles can occur on the very day that particle levels are high, or up to a month or two afterward.

Sources: vehicles, industry, and agriculture

Air pollution is a mix of hazardous substances from both human-made and natural sources. It is a major threat to global health and prosperity, causing more than 6.5 million deaths each year.

Vehicles

Vehicle emissions are a significant source of air pollution. Pollutants from vehicle exhaust include carbon monoxide, nitrogen dioxide, particulate matter (PM), and volatile organic compounds (VOCs). VOCs and semi-volatile organic compounds (SVOCs) are also emitted from interior vehicle materials, such as the cabin and seating. Health effects from vehicle pollution include respiratory and cardiovascular diseases and an increased risk of cancer. Children are particularly vulnerable to high levels of air pollutants from buses.

Industry

Industrial air pollution is a pressing issue affecting the health and well-being of individuals and the environment. Factories, mines, and transportation release harmful substances into the air, including particulate matter, sulfur dioxide, nitrogen oxides, and other toxic chemicals. Long-term exposure to these pollutants can cause respiratory diseases, cancers, decreased lung function, and asthma.

Agriculture

Agriculture is both a contributor to and a victim of air pollution. Ammonia emissions from livestock manure and chemicals comprise 95% of ammonia emissions, which account for 58% of particulate matter air pollution in European cities. Chemical drift with pesticides, herbicides, and fertilizers can also reach nearby lands and neighbourhoods, contributing to poor air quality. At the same time, air pollution negatively impacts agriculture, with ground-level ozone pollution from fuel burning and chemical use predicted to reduce staple crop yields globally.

Natural causes: wildfires, volcanic eruptions, and organic decomposition

Air pollution is a mix of hazardous substances from both human-made and natural sources. Natural sources of air pollution include wildfires, volcanic eruptions, and organic decomposition.

Wildfires

Wildfires are often caused by people, but they are still considered a natural source of air pollution. They release smoke and other hazardous substances into the atmosphere. Wildfires also release particulate matter (PM), which is composed of chemicals such as sulfates, nitrates, carbon, or mineral dusts. PM2.5, a subset of PM, is particularly harmful as it can be inhaled deeply into lung tissue and contribute to serious health problems.

Volcanic Eruptions

Volcanic eruptions release ash and gases, including carbon dioxide, sulphur dioxide (SO2), and hydrogen fluoride (HF), into the atmosphere. These gases can have severe detrimental impacts on the Earth's biosphere, including plant life and the respiratory systems of humans and animals. Sulphur dioxide, in particular, contributes to acid rain on a global scale. For example, the 1980 eruption of Mount St. Helens released an ash cloud that migrated across the United States in three days and reached around the world in 15 days.

Organic Decomposition

Organic decomposition, such as composting, is a natural process that can also contribute to air pollution. During composting, organic material is oxidized, releasing greenhouse gases like carbon dioxide (CO2) and methane (CH4). Composting facilities can also emit ammonia (NH3) and volatile organic compounds (VOCs), which are of particular concern as they are precursors of secondary fine particulate matter (PM2.5) and tropospheric ozone, both of which impact human health and sensitive vegetation.

Types: smog, soot, and ozone

Air pollution is a mix of hazardous substances from both human-made and natural sources. It is a major threat to global health and prosperity, causing more than 6.5 million deaths annually worldwide.

Smog

Smog, sometimes referred to as ground-level ozone, occurs when emissions from combusting fossil fuels react with sunlight. Ground-level ozone is a harmful air pollutant that irritates the eyes and throat and damages the lungs, especially in children, the elderly, and people who work or exercise outdoors. It exacerbates symptoms for those with asthma or allergies and can trigger asthma attacks.

Soot

Soot is a type of particulate matter composed of tiny particles of chemicals, soil, smoke, dust, or allergens carried in the air. It is formed by the incomplete burning of hydrocarbons or organic fuel, such as wood, and can include non-carbon elements like sulphur. Soot is a significant contributor to hazardous air pollution, with diesel exhaust pollution accounting for over one-quarter of total hazardous pollution in the air. Long-term exposure to soot in urban areas increases the risk of coronary artery disease, and it has been linked to acute vascular dysfunction and increased thrombus formation.

Ozone

Ozone is an atmospheric gas that becomes harmful when present at ground level, where it is the main ingredient in smog. It is created when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react with sunlight. Ground-level ozone is particularly harmful to human health and the environment, and it can be transported by wind, affecting even rural areas.

To protect public health, regulatory agencies like the U.S. Environmental Protection Agency (EPA) work to limit the levels of these harmful air pollutants.

Prevention: cleaner energy, transport, and land use

Air pollution is a mix of hazardous substances from both human-made and natural sources. It is a major threat to global health and prosperity, causing an estimated seven million deaths worldwide every year.

The prevention of air pollution requires a multi-faceted approach that targets various sources of pollution. Here are some strategies focused on promoting cleaner energy, transport, and land use:

Cleaner Energy

• Transition to cleaner energy sources: This involves reducing the use of fossil fuels and increasing the adoption of renewable and sustainable energy sources such as solar, wind, and hydroelectric power.
• Improve energy efficiency: By using energy-efficient technologies and practices, we can reduce the overall demand for energy, thereby decreasing the amount of pollution generated.
• Regulate emissions: Governments and organizations can implement regulations and standards to limit the emission of harmful pollutants from power plants, industrial facilities, and other sources. For example, the Clean Air Act in the United States aims to improve air quality by regulating emissions.

Cleaner Transport

• Electric vehicles: Encouraging the use of electric vehicles (EVs) can significantly reduce emissions from road transport. Unlike traditional petrol or diesel engines, EVs produce zero tailpipe emissions.
• Sustainable public transportation: Investing in and promoting sustainable public transportation options, such as electric buses, trains, and bicycles, can help reduce the number of private vehicles on the road, thereby lowering overall emissions.
• Aircraft and shipping emissions: Addressing emissions from aircraft and shipping industries, such as by adopting cleaner fuels and technologies, is crucial due to the significant contribution of these sectors to air pollution.

Cleaner Land Use

• Sustainable land management practices: Implementing sustainable land use practices can help reduce air pollution. This includes strategies such as reforestation, conservation tillage in agriculture, and the restoration of natural habitats.
• Waste management: Improving waste management practices can reduce the amount of pollution from waste incineration. This involves promoting recycling, composting, and proper disposal methods to minimize the open burning of waste.
• Agriculture and livestock emissions: Adopting agricultural practices that reduce emissions, such as precision farming, improved livestock management, and the use of renewable energy sources, can help mitigate pollution from the agriculture sector.

By focusing on cleaner energy, transport, and land use, we can significantly reduce air pollution, improve public health, and mitigate the impacts of climate change. These strategies require collaboration between governments, industries, and individuals to implement effective policies, technologies, and behavioral changes.

Frequently asked questions