Water pollution is caused by

Water pollution is caused by the introduction of harmful substances into water bodies such as rivers, lakes, oceans, and groundwater, resulting in a detrimental change in water quality and posing a threat to human health, ecosystems, and the environment. Some of the primary sources and causes of water pollution include:

1. Industrial Waste: Factories and industrial plants release pollutants such as heavy metals, toxic chemicals, and radioactive waste into waterways, often as a result of insufficient treatment of waste products.

2. Agricultural Runoff: Pesticides, fertilizers, and animal waste from farms can be washed into rivers and lakes, leading to nutrient pollution, which can cause excessive growth of algae and harm water quality and marine life.

3. Sewage and Wastewater: Untreated or inadequately treated sewage from households and commercial establishments can contain pathogens, nutrients and chemicals that contaminate water bodies.

4. Oil Spills: Accidental spills and leaks during the extraction, transport, or use of petroleum products can release large amounts of oil into oceans and rivers, which can be devastating to marine ecosystems.

5. Plastic and Litter: Improperly disposed-of plastics and other trash can end up in water bodies, where they break down into microplastics that are harmful to wildlife and can enter the food chain.

6. Urban Runoff: Urban areas can contribute pollutants such as gasoline, oil, heavy metals and debris from roads and infrastructure into water systems during rainfall or snowmelt these are often carried by storm water.

7. Mining Activities: Mining operations can lead to the release of sediments, chemicals and heavy metals into nearby streams and rivers, disrupting habitats and water quality.

8. Chemical and Nuclear Plants: Accidents or leaks can result in hazardous substances entering water sources, with long-term effects on ecosystems and human health.

9. Thermal Pollution: Discharge of warm water from power plants and industrial facilities can raise the temperature of water bodies, adversely affecting aquatic life which often has a narrow temperature tolerance.

Addressing water pollution typically involves improving waste treatment facilities, enforcing environmental regulations, adopting sustainable practices across various industries and increasing public awareness about the importance of water conservation and pollution prevention.