Any undesirable indesirable change in the physical, chemical and biological properties of tthe
soil. that adversely adversely affects its productivity, is lled soil pollution. Main cause of soil
pollution is the increasing human activities like waste dumping, use of agro-chemi
ils, niung rations and urbanisation.
Sources of Soil Pollution
Main sources of soil pollution are discussed below
The main source of soil pollution is the dumping of industrial wastes, municipal
wastes, and medical or hospital wastes.
Industrial solid wastes and sludge contain toxic organic and inorganic chemical compounds and heavy metals, which can severely affect the fertility of the soil
Industrial emissions from the tall chimneys always come back to the earth’s surface and can pollute surrounding land.
Radioactive wastes from nuclear testing laboratories also contaminate the soil.
Because of their longer half lives, radioactive substances thrive in the soil for long periods.
- Municipal Wastes
These include domestic and kitchen wastes, hospital wastes, livestock and poultry wastes, slaughterhouse wastes, waste metals, glass and ceramic wastes, etc.
Most of these wastes (plastics, polythene bags, glass bottles, vials, etc.) are non-biodegradable.
These wastes persist in soil for long periods and create hindrance in the normal recycling of the soil contents.
Exclusive use of agrochemicals like pesticides amd weedicides can signifantly reduce the fertility of the soil in the long run.
The excessive use of inorganic fertilisers not only contaminate the sOil but also
adversely affect the quality of groundwater
Inorganic nutrients like phosphate and nitate may be washed out to water bodies. After reaching the water bodies, these inorganic fertilisers accelerate eutrophication, and thereby cause the death of aquatic organisms.
Excess of nitrate ions in the soil may also pollute the ground drinking Water.
Inorganic fertilisers and pesticides change the chemical properties of soil and adversely affect soil organisms.
4. Mining Operations
Opencast mining (a process where the surface of the earth is dug open to
bring out the underground mineral deposits) badly damages the topsoil and
contaminates the area with toxic metals and chemicals.
Control of Soil Pollution
Control measures for soil pollution and land degradation involve following
O Safer land us e,
Controlled developmental activities,
Safe disposal and management of solid wastes from industries and human habitations. This involves following measures
(a) Collection and categorisation of wastes,
(b) Recovery of resources like scrap metals, plastics, etc., for recycling and reuse, and
(c) Safe disposal with minimum environmental hazards. Solid wastes may be used as landfills and can be used to construct roads. Solid waste may be subjected to processes like incneration (burning in presence of oxygen) and pyrolysis (combustion in the absence of oxygen).
Noise could be defined as unwanted and unpleasant sound. Common things, which often cause noise, include factories, traffic, television, stereo systems, loud speakers, etc.
Intensity of Sound
Noise, is the amount of sound energy that can not be tolerated by organisms, Sound
travels in the form of pressure waves. The intensity of sound waves is the average rale
per unit area (of the surface) at which the energy is transferred by the wave on to the
surface. It is expressed as W/m2.
lt 1s the logarithm of ratio of the ambient intensity to the reference intensity, sTepresented by an unit, called decibel (dB). When ambient intensity is equal to trence intensity, the sound level is 0 dB. Noise level for the ity has been standardize cbels. However, noise level up to 65 decibel is well tolerated. Nose above
decibels causes discomfort in man and at 120 – 140 decibel produces pain.
Effects of Noise Pollution
The Following are some of the important effects of noise pollutionTags: SOIL POLLUTION