Agents Causing Pollution:
(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
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:
(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.
Nuclear power plant
- 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.
- 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.
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:
- Natural Pollution: