1. What are the main sources and health effects of air pollution? (5 marks) Answer: The main sources of air pollution are combustion of fossil fuels, industrial emissions, wildfires, tobacco smoke, and indoor sources such as cooking and heating. The health effects of air pollution include respiratory diseases, cardiovascular diseases, cancer, stroke, and premature death. (Reference: WHO) 2. What are the main types and sources of water pollution? (5 marks) Answer: The main types of water pollution are chemical, biological, and physical. The main sources of water pollution are agricultural runoff, sewage and wastewater, industrial effluents, mining activities, oil spills, and marine litter. The health effects of water pollution include diarrheal diseases, cholera, typhoid, hepatitis, dysentery, and parasitic infections. (Reference: WHO) 3. What are the main causes and consequences of climate change? (5 marks) Answer: The main causes of climate change are human activities that increase the concentration of greenhouse gases in the atmosphere, such as burning fossil fuels, deforestation, agriculture, and land use changes. The consequences of climate change include rising temperatures, melting ice caps and glaciers, sea level rise, extreme weather events, droughts, floods, heat waves, wildfires, biodiversity loss, food insecurity, water scarcity, and displacement of populations. (Reference: IPCC) 4. What are the main principles and strategies of waste management? (5 marks) Answer: The main principles of waste management are the waste hierarchy, which prioritizes prevention, reduction, reuse, recycling, recovery, and disposal of waste; the polluter pays principle, which holds that the producer or generator of waste should bear the cost of its management; and the precautionary principle, which states that preventive measures should be taken when there is uncertainty about the potential harm of waste. The main strategies of waste management are source separation, collection, transportation, treatment, and disposal of waste. (Reference: UNEP)