Soil pollution

Soil pollution

Intended
Learning Outcomes

At the end of this
session, students will be able to

• Explain soil Pollution

• Describe the factors effecting soil pollution

• Discuss the effect of soil pollution

• Discuss control of soil pollution

Content

• Soil Pollution

• Factors effecting soil pollution

• Effect of soil pollution

• Control of soil pollution

Soil
pollution

• Soil pollution is defined as the build-up in soils of
persistent toxic compounds, chemicals, salts, radioactive materials, or disease
causing agents, which have adverse effects on plant growth and animal health

• Soil is the thin layer of organic and inorganic materials
that covers the Earth’s rocky surface.

• Organic portion, which is derived from the decayed remains
of plants and animals is concentrated in the dark uppermost topsoil

• Inorganic portion made up of rock fragments was formed
over thousands of years by physical and chemical weathering of bedrock

• Productive soils are necessary for agriculture to supply
the world with sufficient food

Types of
Soil Pollution

• Agricultural Soil
Pollution

i) Pollution of surface soil

ii) Pollution of underground soil

• Soil pollution by
industrial effluents and solid wastes

i) Pollution of surface soil

ii) Disturbances in soil profile

• Pollution due to
urban activities

i) Pollution of surface soil

ii) Pollution of underground soil

Soil
Pollution

• Contaminations of the soil by human and natural activities
which may cause harmful effects on living beings

• This may be due to
the following factors

• Industrial wastes:
Industries are the major causes for soil pollution Textiles, steel, paper,   Cement, oil, dyeing and other industries are
responsible for soil pollution.  Toxic
organic compounds and phenol destroy the fertility of the soil.

• Biological agents –
Fungi, protozoa, bacteria are important Biological agents for soil pollution.
The human and animal wastes, garbage, waste water generates heavy soil
pollution

• Radio active
pollutants:
Atomic reactor, nuclear radioactive devices releases
radioactive pollutants. These pollutants enter the land and accumulate there by
causing soil pollution

• Pesticides:
Pesticides pollute the soil.

There are of two types

(1) Chlorinated hydrocarbon insecticide

(2) Organic phosphorous pesticides

• Common chlorinated hydrocarbon insecticides are DDT, BHC

• Organo phosphorous insecticides are synthetic chemicals
like Malathion and parathion. DDT reduces the activity of sex hormones of male
and

• Land with fungicides insecticides causes diseases to human
beings

• Fertilizers:
These discharge N, Na, K, S, Nitrates etc., into the soil. The nitrate causes
cancer

• Polymer, Plastics
& other water:
  These materials
appear as garbage. Solid wastes and their quantities increase day by day. They
pollute the atmospheres, land and also water badly

• Agricultural
practices:
Modern agriculture practices pollute the soil to a large
extent.   Today huge quantities of
fertilizers, pesticides, and weedicides are added to increase the crop field.
Apart from these farm wastes, manure debris, soil erosion containing inorganic
chemicals are causing

Effect of
soil pollution

• Organic wastes enter the soil pores and decompose

• Pathogenic bacteria spread infection

• Compounds containing As, Hg, Cr, Ni, Zn and Fe are toxic
to life

• Fluorides affect plant development

• Water logging and salinity increase the dissolved salt
content in the soil

• Some plants are very sensitive to soil PH and salinity

• Thus land becomes unfit for irrigation

Control of
soil pollution

• Treat the sewage before land disposal

• Rotate the crop pattern to allow the soil replenish the
nutrients

• Preserve and protect top fertile soil, control soil
erosion by tree plantation

• Fertilizers may be applied only after estimating the soil
and crop measures

• Production of natural fertilizers Excessive use of
chemical fertilizers and insecticides should be avoided.  Bio pesticides should be used instead of
toxic chemical pesticides

• Proper hygienic condition- People should be trained
regarding the sanitary habits

• Recycling and reuse of waster – The wastes such as paper,
plastic, metals, glasses should be recycled and used.

Summary

• Contaminations of the soil by human and natural activities
which may cause harmful effects on living beings

• Various factors are responsible for soil pollution like
Industrial wastes, Biological agents etc

• Soil pollution may cause pathogenic bacteria spread
infection etc

• Soil pollution can be controlled by treating the sewage
before land disposal, Rotate the crop pattern to allow the soil replenish the
nutrients etc