AQA GCSE FOUNDATION Chemistry: Air Pollution

AQA GCSE Foundation Chemistry: Air Pollution

Introduction

Air pollution is the contamination of the atmosphere by harmful substances. These substances can come from natural sources like volcanic eruptions and forest fires, but most air pollution is caused by human activities. This tutorial focuses on common air pollutants, their sources, and their effects.

Common Air Pollutants

1. Carbon Monoxide (CO)

• Source: Incomplete combustion of fossil fuels (e.g., petrol, diesel, coal) in vehicles and power stations.
• Effects: CO binds to haemoglobin in the blood, reducing its ability to carry oxygen, leading to headaches, dizziness, and even death.

2. Sulphur Dioxide (SO2)

• Source: Burning of fossil fuels containing sulfur impurities, especially coal-fired power stations.
• Effects: SO2 dissolves in rainwater to form acid rain, which damages buildings, trees, and ecosystems. It also irritates the respiratory system, causing breathing problems.

3. Nitrogen Oxides (NOx)

• Source: High-temperature combustion in vehicles and power stations, especially from diesel engines.
• Effects: NOx contributes to the formation of acid rain and smog, which can cause respiratory problems. It also contributes to ozone depletion in the stratosphere.

4. Particulate Matter (PM)

• Source: Incomplete combustion of fossil fuels, industrial processes, and construction activities.
• Effects: PM is a mixture of tiny solid particles and liquid droplets that can be inhaled deep into the lungs, causing respiratory problems, heart disease, and even cancer.

5. Ozone (O3)

• Source: Ozone is formed in the lower atmosphere (troposphere) by reactions involving NOx and volatile organic compounds (VOCs) in the presence of sunlight.
• Effects: Tropospheric ozone is a harmful air pollutant that can damage crops, irritate the lungs, and contribute to respiratory problems.

The Greenhouse Effect and Climate Change

• Greenhouse gases: Certain gases in the atmosphere, like CO2, methane (CH4), and nitrous oxide (N2O), trap heat from the sun, causing the Earth's temperature to rise. This is known as the greenhouse effect.
• Climate Change: Increased levels of greenhouse gases due to human activities are causing the Earth's average temperature to rise, leading to climate change. This includes extreme weather events, sea level rise, and changes in plant and animal life.

Reducing Air Pollution

• Use public transport, cycle, or walk: This reduces emissions from vehicles.
• Use energy-efficient appliances: This reduces energy consumption and emissions from power stations.
• Reduce, reuse, and recycle: This minimizes waste and pollution from manufacturing and disposal.
• Support sustainable energy sources: Invest in renewable energy sources like solar, wind, and hydro power.
• Plant trees: Trees absorb CO2 from the atmosphere.

Conclusion

Air pollution is a serious environmental problem with significant impacts on human health, ecosystems, and the global climate. By understanding the sources and effects of common air pollutants, we can take action to reduce our impact on the environment and create a healthier future.