Six important Effects of Water Pollution



(1) Physical effect:

These will be due to suspended particle solids, cooling water from power stations and oily surface of films. Suspended solids reduce the water capacity of the dams and reservoirs. These may also cause reduction in solar energy and decrease rate of photosynthesis.

These materials may also cause turbidity, which reduces light penetration. Cooling water from power stations can cause a rise in water temperature and bring about thermal pollution. Increase temperature will cause decrease in fresh water fauna population and increase in flora population. It will cause oxygen-deficiency in water.

Oil will form a thin film on the water surface, which prevents other exchange of oxygen with the atmosphere. It causes water reduction of water oxygen saturation. Spillage from oil tankers in sea will cause marine pollution. It badly affects animal life and seaweeds.

(2) Oxidation effect:

There are two types of oxidation:

(i) Oxidation by the action of bacteria upon organic pollutants.

(ii) Chemical oxidation of other pollutants.

Both types of oxidation involve the use of dissolved oxygen. It will cause increase in Biologic! Oxygen Demand (BOD) resulting deficiency of oxygen in water

(3) Toxic chemical effects:

Some organic and inorganic chemical substances are toxic to plants, animals and humans. They may cause physiological poisoning, respiratory difficulty, decreased photosynthesis and growth. Cadmium, mercury, lead may cause damage to liver, kidneys and brain.

Acids and alkalies may change the pH value of water.

(4) Chemical Nutrient effects:

plants and animals for maintaining their growth and metabolism require chemical nutrients. The nutrient levels slowly rise as a result of the bio- degradation of dead organic material. This rise in nutrients is called "Eutrophication."

Excess nitrates will cause blood diseases and gastric cancer. Green and blue green algae and blanket weed reduces light penetration. It will cause adverse condition for swimming, bathing and fishing.

(5) Micro-Organism Effects:

Wastes that are discharged into water contain pathogenic organisms that are capable of transmitting human diseases. Bacteria are responsible for cholera, typhoid, hepatitis etc.

(6) Radio-nuclide Effects:

Discharge of radioactive materials into air and water system results into long-term pollution hazard effects.

1. The effect cause genetic damage.

2. Chernobyl disaster in USSR is of more serious nature. 40 deaths and radioactive fallout] over widespread region