Sources of Water Pollution

There are various classifications of water pollution. The two chief sources of water pollution can be seen as Point and Non Point.

Point refer to the pollutants that belong to a single source. An example of this would be emissions from factories into the water.

Non Point on the other hand means pollutants emitted from multiple sources. Contaminated water after rains that has traveled through several regions may also be considered as a Non-point source of pollution.

Causes of Water Pollution

Let us now study the causes of water pollution.

1. Industrial waste: Industries produce huge amount of waste which contains toxic chemicals and pollutants which can cause air pollution and damage to us and our environment. They contain pollutants such as lead, mercury, sulphur, asbestos, nitrates and many other harmful chemicals. Many industries do not have proper waste management system and drain the waste in the fresh water which goes into rivers, canals and later in to sea. The toxic chemicals have the capability to change the color of water, increase the amount of minerals, also known as Eutrophication, change the temperature of water and pose serious hazard to water organisms.

2. Sewage and waste water: The sewage water carries harmful bacteria and chemicals that can cause serious health problems. Pathogens are known as a common water pollutant.

3. Mining activities: Mining activities emit several metal waste and sulphides from the rocks and is harmful for the water.

4. Marine dumping: The garbage produce by each household in the form of paper, aluminum, rubber, glass, plastic, food if collected and deposited into the sea in some countries. These When such items enters the sea, they not only cause water pollution but also harm animals in the sea.

5. Accidental Oil leakage: Oil spill pose a huge concern as large amount of oil enters into the sea and does not dissolve with water; there by opens problem for local marine wildlife such as fish, birds and sea otters. For e.g.: a ship carrying large quantity of oil may spill oil if met with an accident and can cause varying damage to species in the ocean depending on the quantity of oil spill, size of ocean, toxicity of pollutant.

6. Burning of fossil fuels: Fossil fuels like coal and oil when burnt produce substantial amount of ash in the atmosphere. The particles which contain toxic chemicals when mixed with water vapor result in acid rain. Also, carbon dioxide is released from burning of fossil fuels which result in global warming.

7. Chemical fertilizers and pesticides: when chemicals are mixed up with water produce harmful for plants and animals. Also, when it rains, the chemicals mixes up with rainwater and flow down into rivers and canals which pose serious damages for aquatic animals.

Common water pollutants are-

Major water pollutants are as follows:

1) Sewage - Sewage pollutants include domestic and hospital wastes, animal and human excreta etc. The sewage let off cause’s oxygen depletion, spread of diseases/epidemics.

2) Metals - Metals like mercury are let off into water bodies from industries. Heavy metals like mercury cause poisoning and affect health causing numbness of tongue, lips, limbs, deafness, blurred vision and mental disorders.

3) Lead - Industrial wastes also lead to Lead pollution. If lead enters the human body system in higher quantities it affects RBCs, bone, brain, liver, kidney and the nervous system. Severe lead poisoning can also lead to coma and death.

4) Cadmium - Source for cadmium pollution is industries, fertilizers. Cadmium gets deposited in visceral organs like liver, pancreas, kidney, intestinal mucosa etc. Cadmium poisoning causes vomiting, headache, bronchial pneumonia, kidney necrosis, etc.

5) Arsenic - Fertilizers are source for arsenic pollution. Arsenic poisoning causes renal failure and death. It also causes liver and kidney disorders, nervous disorders and muscular atrophy, etc.

6) Agrochemicals like DDT - It is a pesticide. Accumulation of these pesticides in bodies of fishes, birds, mammals and man affects nervous system, fertility and causes thinning of egg shells in birds.

7) Bacteria, Viruses and Parasites - These are sourced from human and animal excreta, they are infectious agents.

8) Plastics, Detergents, Oil and Gasoline - They are a waste from industries, household and farms. They trigger organic pollution and is harmful to health.

10) Inorganic Chemicals - Inorganic chemicals like acids, salts, metals are a result of industrial effluents, household cleansers, and surface run-off and are injurious to health.

11) Radioactive Materials - Mining and ores processing, power plants, weapons production and natural give rise to radioactive pollution like that of uranium, thorium, cesium, iodine and radon. Radioactive pollution causes serious health diseases to all organisms.

12) Sediments - Sedimentation of soil, silt due to land erosion and deposition causes disruption in ecosystem.

13) Plant Nutrients - Nutrients like nitrates, phosphates, and ammonium are let off from agricultural and urban fertilizers, sewage and manure. Excess of nutrients cause eutrophication and affect the ecosystem.

14) Animal Manure and Plant Residues - These substances in water causes increased algal blooms and microorganism population. This increases oxygen demand of water, affecting aquatic ecosystem. This is introduced into water due to sewage, agricultural run-off, paper mills, food processing etc.

15) Thermal Pollution - Temperature changes of water caused due to using water as cooling agent in power plants and industries causes increase in water temperature affecting the aquatic life.