Lesson Notes By Weeks and Term v5 - Grade 9

Lesson Video

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Performance objectives

• Identify 3 major negative human impacts in South Africa.
• Explain the consequences on ecosystems and human health.
• Outline strategies to reduce these negative impacts.
• Analyse the impact of population growth and urbanization.
• Assess different waste management strategies.

Lesson summary

The Earth provides us with everything we need to survive: air, water, food, and shelter.

However, human activities are increasingly impacting the environment in ways that threaten these resources and the delicate balance of our ecosystems. This is especially relevant in South Africa, where we face unique environmental challenges such as water scarcity, pollution from mining and industry, and the loss of biodiversity due to habitat destruction. Understanding how our actions affect the environment is crucial for creating a sustainable future for ourselves and future generations.

Lesson notes

2. 1.

Air Pollution: Air pollution occurs when harmful substances are released into the atmosphere, affecting air quality. In South Africa, major sources of air pollution include: Burning of Fossil Fuels: Coal-fired power plants, vehicles, and industries release pollutants like sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter (PM). Mpumalanga, a province with a high concentration of coal-fired power plants, often experiences severe air pollution. These pollutants can cause respiratory problems, cardiovascular diseases, and even cancer.

Mining Activities: Dust from mining operations, particularly gold and coal mining, contributes significantly to air pollution. This dust can contain harmful heavy metals like lead and mercury, which can be inhaled and cause serious health problems.

Burning of Waste: Illegal dumping and burning of waste release toxic fumes into the air. This is a common problem in informal settlements where waste management services are limited.

Industrial Emissions: Factories release various pollutants depending on their processes. Examples include chemical plants emitting volatile organic compounds (VOCs) and refineries releasing hydrocarbons.

Example: A community living near a coal-fired power station in Mpumalanga experiences frequent respiratory illnesses, especially among children and the elderly. This is because the power station releases sulfur dioxide and particulate matter, which irritate the lungs and exacerbate pre-existing conditions like asthma. 2.

2. Water Pollution: Water pollution occurs when harmful substances contaminate water bodies, making them unsafe for drinking, irrigation, and aquatic life. In South Africa, major sources of water pollution include: Industrial Effluents: Industries often discharge untreated or poorly treated wastewater containing chemicals, heavy metals, and organic pollutants into rivers and dams.

Agricultural Runoff: Fertilizers, pesticides, and animal waste from farms can wash into water bodies, causing eutrophication (excessive nutrient enrichment). Eutrophication leads to algal blooms, which deplete oxygen in the water, killing fish and other aquatic organisms.

Mining Activities: Acid mine drainage (AMD) is a major water pollution problem in South Africa. When water flows through abandoned or active mines, it becomes acidic and dissolves heavy metals from the rocks. This contaminated water can pollute rivers and groundwater.

Sewage: Untreated or poorly treated sewage contains pathogens (disease-causing microorganisms) and organic matter that can contaminate water sources and cause waterborne diseases like cholera and typhoid.

Informal Settlements: Lack of proper sanitation and waste management in informal settlements leads to water pollution due to open defecation and improper disposal of waste.

Example: The Witwatersrand region, historically a major gold mining area, suffers from severe acid mine drainage. The acidic water, containing heavy metals, pollutes the Vaal River, a crucial water source for Gauteng province. This pollution threatens water security and the health of communities that depend on the river. 2.

3. Soil Pollution: Soil pollution occurs when harmful substances contaminate the soil, affecting its fertility and posing risks to human and animal health. In South Africa, major sources of soil pollution include: Mining Activities: Mining activities release heavy metals and other pollutants into the soil. Tailings dams (reservoirs of mining waste) can leak, contaminating surrounding soil and groundwater.

Agricultural Practices: Excessive use of fertilizers and pesticides can contaminate the soil with harmful chemicals.

Industrial Waste: Improper disposal of industrial waste can lead to soil contamination with heavy metals, solvents, and other pollutants.

Waste Disposal: Landfills can leak harmful chemicals into the soil, polluting it and groundwater.

Oil Spills: Oil spills from pipelines or tankers can contaminate large areas of soil, making it unusable for agriculture.

Example: Farmland near a gold mine in Gauteng is found to be contaminated with arsenic and lead. These heavy metals have leached from mine tailings dams into the soil, making it unsuitable for growing crops and posing a health risk to people who consume food grown in the contaminated soil. 2.

4. Deforestation and Habitat Loss: Deforestation is the clearing of forests for other land uses, such as agriculture, urbanization, and mining. Habitat loss is the destruction of natural habitats, making them unsuitable for wildlife. In South Africa, major drivers of deforestation and habitat loss include: Agriculture: Clearing forests to create farmland for crops and livestock.

Urbanization: Expansion of cities and towns to accommodate growing populations.

Mining: Clearing forests to make way for mines and related infrastructure.

Illegal Logging: Harvesting timber illegally.

Invasive Alien Species: Plants that outcompete native species and alter ecosystems.