Atmospheric Pollution

This section explains atmospheric pollution covering, pollutants and fuels, properties and effects of atmospheric pollutants and a summary of atmospheric pollutants.

Pollutants from Fuels

When fossil fuels such as coal, oil, and natural gas are burned for energy, transport, or industry, they release several harmful pollutants into the atmosphere. These pollutants can have a range of negative effects on both human health and the environment. Some of the key pollutants produced from the combustion of fuels include:

• Carbon monoxide (CO)
• Sulphur dioxide (SO₂)
• Oxides of nitrogen (NOx)
• Particulates (including soot)

Each of these pollutants has distinct properties and contributes to various environmental and health problems.

Properties and Effects of Atmospheric Pollutants

Carbon Monoxide (CO)

Properties:
Carbon monoxide is a colourless, odourless gas that is formed when carbon-containing fuels (such as wood, coal, petrol, and natural gas) are burned incompletely, due to insufficient oxygen supply.

Effects:

• Health risks: Carbon monoxide is toxic when inhaled because it binds to haemoglobin in the blood more readily than oxygen, reducing the amount of oxygen that can be transported to tissues. This can lead to symptoms such as headaches, dizziness, confusion, and in extreme cases, death.
• Environmental impact: While carbon monoxide itself does not directly contribute to climate change, its presence can indirectly affect atmospheric processes, including the formation of ground-level ozone (a component of smog).

Sulphur Dioxide (SO₂)

Properties:
Sulphur dioxide is a colourless gas with a strong, choking smell. It is produced when fuels containing sulphur, such as coal and oil, are burned. It can also be released from volcanic eruptions.

Effects:

Health risks: Sulphur dioxide can irritate the respiratory system, leading to conditions such as asthma, bronchitis, and other lung diseases. Prolonged exposure can worsen these conditions.

Environmental impact: 

• Acid rain: Sulphur dioxide reacts with water vapour in the atmosphere to form sulphuric acid, which can fall as acid rain. Acid rain can damage buildings, monuments, and vegetation, and harm aquatic ecosystems by lowering the pH of water bodies.
• Smog formation: Sulphur dioxide can also contribute to the formation of smog, a mixture of air pollutants that reduces visibility and harms air quality.

Oxides of Nitrogen (NOx)

Properties:
Nitrogen oxides, primarily nitroge monoxide (NO) and nitrogen dioxide (NO₂), are produced when nitrogen in the air reacts with oxygen during high-temperature combustion processes, such as in car engines and power stations.

Effects:

Health risks: Nitrogen dioxide is a potent irritant to the respiratory system, and long-term exposure can lead to respiratory diseases such as asthma and bronchitis. It can also make the lungs more susceptible to infection.

Environmental impact: 

• Acid rain: Nitrogen oxides can react with water vapour to form nitric acid, contributing to acid rain, which harms plant life, water sources, and infrastructure.
• Smog formation: NOx gases play a key role in the formation of photochemical smog, which is a mixture of pollutants that can cause eye irritation, respiratory issues, and reduce air quality.
• Contribution to global warming: Nitrous oxide (N₂O), a form of nitrogen oxide, is a potent greenhouse gas that contributes to global warming.

Particulates (Soot)

Properties:
Particulates are tiny solid particles or liquid droplets suspended in the air. They can be produced from the incomplete combustion of fuels (such as in diesel engines) or by natural sources such as dust and volcanic activity.

Effects:

Health risks: Particulate matter can be inhaled into the lungs, leading to respiratory problems such as asthma, lung cancer, and heart disease. Fine particulates (PM2.5), which are smaller than 2.5 micrometres in diameter, can penetrate deep into the lungs and even enter the bloodstream.

Environmental impact: 

• Reduced visibility: Particulates contribute to haze and reduce visibility, especially in urban areas.
• Climate effects: Some particulates, particularly black carbon (a component of soot), can absorb sunlight, leading to localised warming. In contrast, other particulates may reflect sunlight, potentially contributing to regional cooling. However, their overall effect on global climate is complex and still under study.

Summary of Atmospheric Pollutants

Atmospheric pollution, primarily from the burning of fossil fuels, has significant impacts on both human health and the environment. Pollutants such as carbon monoxide, sulphur dioxide, oxides of nitrogen, and particulates contribute to respiratory diseases, acid rain, smog, and climate change. Understanding these pollutants and their effects is crucial in developing strategies to reduce emissions and protect public health and the planet.