Water pollution is harmful because it introduces substancesāsuch as toxic chemicals, excess nutrients, and sedimentāthat upset the balance of aquatic ecosystems and degrade water quality. These pollutants interfere with natural processes and reduce vital resources. For example, certain chemicals can poison aquatic organisms directly, while sediment can bury habitats. Heated water from industrial sources can deplete dissolved oxygen in the water, making it difficult for species like trout to survive.
Water pollution poses significant health risks to humans and wildlife. Pathogenic microorganisms from domestic sewage can cause diseases, while industrial wastes may contain toxic chemicals and heavy metals that can cause poisoning or long-term health issues. Microplastics found in water bodies can enter the food chain, potentially affecting top consumers, including humans, through seafood consumption.