Question

State four effects of fresh water pollution.

Answer 1

1. Eutrophication: excess nitrates and phosphates cause algal blooms that deplete dissolved oxygen, killing fish and other aquatic life.

2. Biomagnification/toxic buildup: persistent chemicals, e.g., mercury, pesticides, concentrate up the food chain and harm predators, including people who eat contaminated fish.

3. Disease spread: sewage and pathogens in polluted freshwater cause water‑borne illnesses such as cholera, typhoid, diarrhoea, and hepatitis.

4. Chemical poisoning and chronic health effects: heavy metals and industrial chemicals in freshwater can cause poisoning and long‑term impacts, e.g., neurological damage, cancer, and organ failure.