Agents Causing Pollution | NTA UGC NET | Paper 1

Agents Causing Pollution:

Depending upon the nature of the pollutants and their inter­action with environment process, the pollution caused by differ­ent agents can be classified into the following categories:

 

(a) Pollution caused by solid wastes.

 

(b) Pollution caused by liquid wastes.

 

(c) Pollution caused by gaseous wastes.

 

(d) Pollution caused by wastes without weights.

(a) Pollution caused by Solid wastes:

The solid wastes in­cludes the pollutants like garbage, rubbish, ashes, large wastes formed due to demolition and construction processes, dead ani­mals wastes, agricultural wases etc. From the above examples, it is clear that the solid wastes may be domestic and industrial in nature.

 

(b) Pollution caused by liquid wastes:

Oxygen cycle is nicely operated in aquatic system maintaining ecological balance. That is, the dissolved oxygen is used by aquatic living organisms for their respiration and in return, these liberate carbon dioxide. Car­bon dioxide molecules are again used by green plants and algae in the process of photosynthesis.

If liquid industrial wastes containing acids, alka­lis and poisonous substances enter the river, the aquatic life is affected and self-purification system of water is impaired. Pesticides and herbicides which enter water may Kill some organisms or accumulate in fishes which, when consumed by man, pass on the chemicals giving rise to cumulative poisoning

(c) Pollution caused by Gaseous Wastes:

The gaseous wastes include Carbon monoxide (CO), Sulphur dioxide (SO2), nitrogen dioxide (NO2), Ozone (O3) and smog gases (composed of a com­plex mixture of photochemical oxidation products of hydrocar­bons). These gases are more abundant in the atmosphere of in­dustrial cities.

 

(d) Pollution from Waste without weight:

This type of pollu­tion is also known as pollution by energy waste; Wastes without weight may be of the following types:

(i) Radio–active

(ii) Heat

(iii) Noise

(i) Radioactive Substance:

 

Despite of all possible precau­tions in the functioning and maintenance of nuclear reac­tors, it is seen that minute quantity of radioactive waste escapes out into the environment. From the mining opera­tion of the uranium to the use and final disposal of wastes from the reactor, radioactive materials continuously escape out into the environment. Besides, a lot of radioactive wastes enter into environment during the nuclear tests.

Sources:

Nuclear power plant

Radium

Uranium

Thorium

 

• The impact of radioactive pollution on human beings can vary from mild to fatal; the magnitude of the adverse effects largely depends on the level and duration of exposure to radioactivity.

• Low levels of localized exposure may only have a superficial effect and cause mild skin irritation. 

• Effects of long, but low-intensity exposures include nausea, vomiting, diarrhea, loss of hair, bruises due to subcutaneous bleeding etc. 

• Long-term exposure or exposure to high amounts of radiation cause irreparable damage to DNA molecules and can lead to a life-threatening condition. tumors,  cancers. 
• Skin cancer, lung cancer and thyroid cancer are some of the common types of cancers caused by radiation. 
• Child could have severe congenital birth defects, both physical and mental. This is tragically illustrated in the case of Hiroshima and Nagasaki (Japan) 

• 6 Aug 1945 – 9 Aug 1945, where the aftereffects of nuclear radiation were carried on for generations, and thousands of children were born with physical abnormalities and mental retardation.

• The radiation also brought about a spike in cancer; the region still (after more than 65 years) has a much higher rate of cancer and congenital (disease present from birth) abnormalities than the rest of Japan. 

 

There is no safe limit for radioactivity, since even the smallest amount has some effect on the body and holds the potential to be highly dangerous. 

(ii) Heat:

 

A large quantity of waste heat energy is dissipated into environment by the way of hot liquid streams or hot gases released by industries and automobiles.

 

(iii) Noise:

 

The unwanted sound is known as noise. This sources of noise for the general public are the machines in the in­dustry, traffic noise, indiscriminate use of transistor, radios, public address systems, etc.

Classification of Pollution:

Pollution can be classified according to the environment (air, water, and soil) in which it occurs or according to the type of pol­lutant (lead, mercury, carbon dioxide, solid waste, noise, biocide, heat, etc.) by which pollution is caused.

 

Sometimes, pollution is made to classify into two broad cat­egories:

 

1. Natural Pollution:

 

It originates from the natural process.

 

2. Artificial Pollution:

 

It originates artificially by the interac­tion in between humanity and environment.