Hello! I can help you understand why human wastewater entering bodies of water can be dangerous.
II. Human wastewater can lead to cultural eutrophication in bodies of water. This occurs when excess nutrients from the wastewater, such as nitrogen and phosphorus, cause an overgrowth of algae and aquatic plants. This excessive growth can lead to a decrease in oxygen levels in the water, harming aquatic life.
III. Human wastewater can carry pathogens like bacteria and viruses, which can pose health risks to humans and wildlife that come into contact with contaminated water. These pathogens can cause diseases and infections, making the water unsafe for consumption or recreation.
Therefore, the correct answer is II and III. Human wastewater can indeed lead to cultural eutrophication and carry pathogens, making it hazardous to the environment and human health.