Q.12 Define land pollution. Discuss the causes
of land pollution and their control. (AKTU. - 2008-09)
Related
Questions -
Q. What are the sources of soil
pollution? (AKTU. - 2012 - 13)
Ans. Land Pollution: -
Land
is one of the most important components of our natural environment. Land
provides substratum for the growth of vegetation and crop plants. The topmost
layer of the earth is called soil. Activities such as construction of buildings
and roads deriving raw materials for industries, use of agricultural chemicals,
disposal of wastes, etc., have invariably contaminated the land. Any change in
the physical, chemical, and biological properties of soil due to natural or
man-made activities is known as soil pollution.
Causes Of Land
Pollution: -
Natural Causes: -
Some of the natural causes of soil pollution are
earthquakes, landslides, hurricanes, and floods. Such natural disasters cause
severe damage to the composition of soil.
Man-made Causes: -
Some of the
man-made causes of soil pollution are: -
* Industrial
waste - Industrial wastes contain
different kinds of toxic, flammable, and non-biodegradable substances that may
persist in the soil for a long time and destroy the composition of the soil.
Discharge of large quantities of such industrial wastes on land results in soil
pollution.
* Urbanization
- Urbanization refers to the process
in which large areas of forest and agricultural land are utilized for
residential, commercial, and industrial purposes, it is associated with
industrialization. Construction of dams, houses, factories, etc., leaves the
land in the adjacent areas unfit for agriculture hence contributing to soil
pollution.
* Mining - Mining refers to the process by which non - renewable
substances and valuable minerals are extracted from earth. Mining activities
cause contamination of ground water and surface water by discharge of toxic
mining products into the environment. Mining leads to change in the structure
and composition of the soil and hence causes soil pollution.
* Agricultural
waste - Biodegradable wastes such as
straw, dry twigs, leaves, seeds, grasses, etc., increases soil fertility, while
the excessive use of substances such as chemical fertilizers, pesticides, and
insecticides for agricultural purposes degrades soil quality and causes soil
pollution.
* Domestic
wastes and garbage - Domestic wastes
may include biodegradable wastes such as kitchen and food wastes, paper, cloth,
etc., and non-biodegradable wastes such as glass, plastic materials, metal
cans, etc. Improper disposal of hazardous domestic wastes such as batteries,
paints, medicines, glass bulbs, spray cans, etc., contribute greatly to soil
pollution.
* Radioacitve
wastes - Nuclear power plants,
nuclear testing, and explosions, etc, add variable amount of radioacitve
materials to soil. The addition of these toxic radioactive substances causes
severe soil pollution, and may also have detrimental effects on the living
organisms in and around the area.
Control Of Land Pollution: -
Some of the measures that may be used to control soil
pollution are listed as follows:
* Industrial
wastes and effluents must be treated before being disposed. The treatment of
industrial wastes reduces the toxicity of the harmful elements present in them
thus reducing soil pollution.
* Garbage
from urban areas should be segregated into biodegradable and non-biodegradable
waste products. Biodegradable wastes may be used for the production of manures
and biogas, while the non-biodegradable wastes such as glass, metals, and
plastics may be recycled and reused. This would reduce the pressure on the
environment and hence minimize soil-pollution.
* Planting
of trees must be encouraged. Trees and plants utilize many of the pollutants
during the process of photosynthesis and hence reduce the severity of soil
pollution; they also bind the soil together and prevent the loss of the
fertile topsoil during heavy rains and floods.
* The
disposal of hazardous radioactivity wastes into the soil should be prohibited
as it is almost impossible to completely cleans the soil of radioactive
elements.
* Solid
waste can also be used for electricity generation. In India, such a plant is
established by the Central Mechanical Engineering and Research Institute at
Durgapur. The plant has a capacity to use about 500 kg garbage per hectare as a
result of which approximately 5 KW electricity can be generated.
* The use of
chemical fertilizers and pesticides should be minimized as far as possible. The
use of such fertilizers and pesticides upsets the chemical balance of the soil
by increasing the salinity and alkalinity and hence renders it unfit for
agricultural purposes in the long run.
Q.13. Discuss the effect of soil pollution. (AKTU. - 2012 - 13) Ans. The
effects of pollution on soil are quite alarming and can cause huge disturbances
in the ecological balance and health of living creatures on earth. Some of the
most serious soil pollution effects are:
¨ Decrease in soil fertility and therefore
decrease in the soil yield. How can one expect contaminated soil to produce
healthy crops?
¨Loss of soil and natural nutrients present
in it. Plants also would not thrive in such soil, which would further result in
soil erosion.
¨Disturbance in the balance of flora and
fauna residing in the soil.
¨Increase in salinity of the soil, which
therefore makes it unfit for vegetation, thus making it useless and barren.
¨Generally crops cannot grow and flourish
in polluted soil. Yet, if some crops manage to grow, they would be poisonous
enough to cause serious health problems in people consuming them.
¨Creation of toxic dust is another
potential effect of soil pollution.
¨Foul smell due to industrial chemicals and
gases might result in headaches, fatigue, nausea, etc., in many people.
¨Soil
pollutants would bring in alteration in the soil structure, which would lead to
death of many essential organisms in it. This would also affect the larger
predators and compel them to move to other places, once they lose their food
supply.
