CHEMICAL POLLUTANTS IN WATER.

• Industrial and agricultural activity use many different chemicals that can run-off into water and pollute it.

• Water pollution can come from a number of different sources.

• If the pollution comes from a single source, such as an oil spill, it is called point-source pollution.

• If the pollution comes from many sources, it is called nonpoint-source pollution.

Types of Pollutants• Nitrates – The increased use of fertilisers means that nitrates are

more often being washed from the soil and into rivers and lakes. This can cause eutrophication

• (The process by which water acquires a high concentration of nutrients, especially phosphates and nitrates. These promote excessive growth of algae.

• Phosphates – eutrophication.• Oil – Oil does not dissolve in water, instead it forms a thick layer on

the water surface. This can stop marine plants receiving enough light for photosynthesis. It is also harmful for fish and marine birds.

• Petrochemicals – This is formed from gas or petrol and can be toxic to marine life.

Water Pollution and Disease

• Most diseases in the world are related to water and sanitation.

• Faecal/sewage pollution of water increases the risk of infection.

• Agricultural products.• Septic tanks• Storage tanks (underground)• Landfills.

• BILHARZIA – The parasite penetrates through the skin. Symptoms: an itchy rash, headaches, abdominal pain, diarrhea, bladder infections, fever, enlarged liver and swollen veins.

• MALARIA - Mosquitoes breed in water, especially dams, ponds, water tanks.

• CHOLERA - Caused by bacteria (Vibrio cholerae) that is spread through water contaminated by faeces.