Lesson Notes By Weeks and Term v5 - Grade 10

Lesson Video

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Performance objectives

• Describe major human activities causing environmental degradation.
• Explain the impacts of pollution on ecosystems and human health.
• Discuss consequences of deforestation and overexploitation of resources.
• Describe sustainable practices to reduce human impact.
• Explain the importance of conservation for future generations.

Lesson summary

Environmental studies and human impact are critically important for Grade 10 learners in South Africa because our environment is facing significant challenges like water scarcity, pollution, and biodiversity loss. Understanding these issues is essential for responsible citizenship and building a sustainable future for our country. Many communities, especially in rural areas, directly depend on natural resources for their livelihoods. The environmental challenges also affect the economy through impacts on agriculture, tourism and other key sectors. This week, we'll focus on understanding the specific impacts humans have on the environment and exploring ways to mitigate those impacts.

Lesson notes

2.1 Pollution: Pollution refers to the contamination of the environment by substances that are harmful to living organisms.

There are three main types of pollution: air, water, and land.

Air Pollution: This is caused by the release of harmful gases and particles into the atmosphere.

Major sources include: Burning of fossil fuels (coal, oil, and gas) in power plants, vehicles, and industries. South Africa relies heavily on coal for electricity generation, making it a significant contributor to air pollution. Highveld region is especially affected.

Industrial emissions: Factories release various pollutants, including sulfur dioxide, nitrogen oxides, and particulate matter.

Burning of waste: Open burning of garbage releases toxic fumes and ash.

Mining activities: Dust and particulate matter from mining operations contribute to air pollution.

Indoor air pollution: Burning wood or paraffin for cooking and heating, especially in poorly ventilated areas, poses a significant health risk to low-income households.

Impacts: Air pollution can cause respiratory problems (asthma, bronchitis), cardiovascular diseases, and even cancer. It also contributes to acid rain and climate change. In South Africa, air pollution is a major concern in urban areas and industrial hubs, impacting public health and the environment. Worked

Example: The burning of coal in power plants in Mpumalanga releases sulfur dioxide (SO2) into the air. This SO2 can react with water vapor in the atmosphere to form sulfuric acid (H2SO4), which then falls as acid rain. Acid rain can damage forests, lakes, and buildings, and it can also leach harmful metals from the soil, contaminating water sources.

Water Pollution: This occurs when harmful substances contaminate water bodies, such as rivers, lakes, and oceans.

Major sources include: Industrial discharge: Factories release untreated or poorly treated wastewater containing toxic chemicals, heavy metals, and other pollutants.

Agricultural runoff: Fertilizers, pesticides, and animal waste from farms can contaminate water sources.

Sewage: Untreated or poorly treated sewage releases pathogens and organic matter into water, leading to eutrophication (excessive nutrient enrichment) and oxygen depletion. Many rural communities in South Africa lack adequate sanitation infrastructure, contributing to water pollution.

Mining activities: Acid mine drainage (AMD) is a major environmental problem in South Africa. AMD occurs when water comes into contact with sulfide minerals in mines, forming sulfuric acid and dissolving heavy metals, which can then contaminate water sources.

Oil spills: Accidental spills from ships or oil rigs can devastate marine ecosystems.

Impacts: Water pollution can contaminate drinking water sources, harm aquatic life, and cause waterborne diseases (cholera, typhoid). Eutrophication can lead to algal blooms, which can deplete oxygen levels in water, killing fish and other aquatic organisms. Worked

Example: Untreated sewage released into the Umgeni River in KwaZulu-Natal can contain high levels of bacteria like E. coli. People who drink water contaminated with E. coli can develop diarrheal illnesses. Eutrophication due to nutrient runoff can result in algal blooms that release toxins harmful to both animals and humans.

Land Pollution: This is the contamination of soil and land surfaces.

Major sources include: Improper waste disposal: Landfills are often poorly managed, leading to leachate (contaminated liquid) seeping into the soil and groundwater.

Industrial waste: Factories and mines generate hazardous waste that can contaminate soil and groundwater if not properly managed.

Agricultural practices: Excessive use of fertilizers and pesticides can contaminate soil and harm beneficial organisms.

Mining activities: Tailings dams (reservoirs of mining waste) can leak and contaminate soil and water.

Impacts: Land pollution can contaminate food crops, harm soil organisms, and pollute groundwater. It can also pose risks to human health through direct contact or ingestion of contaminated soil. Worked

Example: Illegal dumping of electronic waste (e-waste) in Gauteng can release toxic heavy metals like lead and mercury into the soil. These metals can then be absorbed by plants or leach into groundwater, posing risks to human health and the environment. 2.2 Deforestation: Deforestation is the clearing of forests for other land uses, such as agriculture, urbanization, and mining.

Causes: Agricultural expansion: Clearing forests to create farmland for crops and livestock.

Logging: Harvesting trees for timber and other wood products.

Mining: Clearing forests to access mineral resources.

Urbanization: Clearing forests to build roads, houses, and other infrastructure.

Fuelwood collection: Cutting down trees for firewood, especially in rural areas.

Impacts: Loss of biodiversity: Forests are home to a wide variety of plants and animals. Deforestation leads to habitat loss and extinction.