1. What are the main sources and health effects of air pollution in urban areas? Answer: The main sources of air pollution in urban areas are motor vehicles, industries, power plants, biomass burning, and household cooking and heating. Air pollution can cause respiratory diseases, cardiovascular diseases, cancer, and premature death. 2. What are the main types of waterborne diseases and how can they be prevented? Answer: The main types of waterborne diseases are diarrheal diseases, typhoid fever, cholera, hepatitis A and E, and schistosomiasis. They can be prevented by improving water quality, sanitation, hygiene, and access to safe drinking water. 3. What are the main environmental risk factors for vector-borne diseases and how can they be controlled? Answer: The main environmental risk factors for vector-borne diseases are climate change, deforestation, urbanization, irrigation, and human-animal contact. They can be controlled by reducing vector habitats, using insecticides, bed nets, repellents, and vaccines, and improving surveillance and response. 4. What are the main causes and consequences of climate change and how can they be mitigated? Answer: The main causes of climate change are greenhouse gas emissions from fossil fuels, agriculture, land use change, and industrial processes. The consequences of climate change include rising temperatures, sea level rise, extreme weather events, biodiversity loss, food insecurity, water scarcity, and health impacts. They can be mitigated by reducing emissions, enhancing sinks, adapting to impacts, and promoting lowcarbon development. 5. What are the main sources and health effects of exposure to hazardous chemicals in the environment? Answer: The main sources of exposure to hazardous chemicals in the environment are industrial activities, agricultural practices, consumer products, waste disposal, and contaminated sites. The health effects of