Sindh Agriculture University

Tando Jam

Department of Soil Science

CONTAMINATION OF SOILS WITH ORGANIC AND

INORGANIC POLLUTANTS

By

MASHOOQ HUSSAIN ODHANO (PhD, Student)

)

Soil contamination Soil contamination is the occurrence of pollutants in soil above a certain level causing a deterioration or loss of one or more soil functions. Also, Soil Contamination can be considered as the presence of man-made chemicals or other alteration in the natural soil environment. This type of contamination typically arises from the rupture of underground storage tanks, application of pesticides, percolation of contaminated surface water to subsurface strata, leaching of wastes from landfills or direct discharge of industrial wastes to the soil. The most common chemicals involved are petroleum hydrocarbons, solvents, pesticides, lead and other heavy metals. The occurrence of this phenomenon is correlated with the degree of industrialization and intensity of chemical usage.

Corrosion of underground storage tanks (including piping used to transmit the contents)

Application of fertilizers and pesticides Mining Oil and fuel dumping Disposal of coal ash Leaching from landfills Direct discharge of industrial wastes to the soil Drainage of contaminated surface water into the soil Discharging urine and faeces in the open

The most common chemicals involved are petroleum hydrocarbons, solvents, pesticides, lead, and other heavy metals.

Causes of Soil contamination

Soil pollution• Soil pollution is defined or can be

described as the contamination of soil of a particular region.

• Soil pollution is caused by addition of chemicals, which reduces it’s productive capacity.

• In rural areas more fertilizers & pesticides are used in agricultural operations & the residual chemicals remain in the top layers of soil.

Pollutants in PakistanPakistan is the seventh most populous country of the world, having a population of more the 180 million. It is developing country with an increasing population density in order to develop its economy, Pakistan requires establishment of new industries. Due to unplanned industrial growth, much of the land and nearby water bodies are polluted by indiscriminate dumping of solid and liquid wastes generated by these units increased levels of metal ions and organic pollutants in the environment are either due to absence of laws for various industries to treat their wastes .

The rapid increase in population, together with the unplanned disposal of effluent from tanneries and textile industries have increased the threat of soil pollution in Pakistan. Faisalabad Effect of industrial effluents discharged by various industries in the industrial area o f Lahore, Sheikhupura and Kala Shah Kaku indicated soil and water contamination of salts and heavy metals in their respective areas. Environmental protection agency studies have been shown that industrial effluents from electroplating and tannery industries containing toxic metals, such as Cr, Ni, As, Hg, Cu, Pt, etc have contaminated soil and biota of these areas by such metals in Faisalabad and Lahore. Pakistan reported that Faisalabad city effluent, comprising of domestic and industrial wastes, contained toxic metals, including Pb, Cu and Cd.

The type of pollutant

ORGANIC POLLUTANTS

INORGANIC POLLUTANTS

1.ORGANIC POLLUTANTS

a. SEWAGE,WASTE FROM TANNRIES,PAPER MILLS, FOOD PROSSESING

INDUSTRIES. SUGAR REFINERIES

DECREASE DISSOLVED OXYGEN

PATHOGENIC MICROORGANISM , EUTROFICATION

b. SYNTHETIC ORGANIC CHEMICALS

( PLASTIC,PAINTS,PHARMA WASTE)

c. PESTICIDES

.

2.INORGANIC POLLUTANTSHEAVY METAL POLLUTANTS

ENTER INTO FOOD CHAIN

AFFINITY FOR SULPHUR;ATTACK SULPHUR BONDS IN ENZYMES

OTHER VULNARABLE SITES ARE COOH OF PROTEIN ALSO BIND TO CELL

MEMBRANE.

A. ORGANIC MERCURIAL: INCECTISIDES & BACTERICIDES, NEUROLOGICAL

DISORDERS

B. CADMIUM: UNCOUPLER OF OXIDATIVE PHOSPHORYLATION

C. BERYLLIUM :PHOSPHATE INHIBITOR

D.STRONTIUM :COMPETITOR FOR CALCIUM IN BONE

Lead, Arsenic, Mercury, and Cadmium (all main industrial pollutants) tend to accumulate in the human body for long periods of time, as they are difficult to flush out of our system.

SOURCES OF SOIL POLLUTION

• Acid rains• Excess application of pesticides, fertilizer.

• Urban solid wastes.

• Disposal of Industrial wastes and sludge over land.

Acid Rain

Acid Rain is caused by air pollution. The acidic water falls on the soil and pollutes it by making the soil acidic.

Fertilizers

The use of excess fertilizers to increase the crop yields makes the soil either acidic or alkaline and pollutes it.

Ex: ammonium sulphate , sodium nitrate

Excess use of Fertilizers

Excess use of Na, Mg, Ca, K, Zn in the form of fertilizers & pesticides inhibit plant growth & reduce crop yield.

Urban wastes These wastes include a

wet and fermentable fraction, made of food residuals from houses, restaurants and food industries, paper.

Industrial waste

This pollution can be very massive in certain areas, where the industries discharge their wastes and really great is the variety of pollutants: heavy metals compounds, asbestos, organic compounds

p0llutants

Excess use of fertilizers Excess use of Na, Mg, Ca, K, Zn, in

the form of fertilizers & pesticides inhabit plant growth & reduce crop yield.

p0llutants effect Humans

Animals

Agricultural

Urban

Humans Effects

Causes cancers including leukemia. Mercury can increase the risk of kidney damage. Also cause headaches, eye irritation & skin rash.

Animals Effects

Small life forms may consume harmful chemicals which may then be passed up the food chain to large animals.

Agricultural Effects

Decrease soil fertility. Reduced crop yield. Larger loss of soil & nutrients. Reduced nitrogen fixation.

Urban Effects Public health problems. Pollution of drinking water sources. Foul smell & release of gases. Waste management problems.

Control of soil pollution

Ban on use of plastic bags which are major cause of pollution in cities.

Recycling of plastic wastes to manufacture many ‘remake’ items.

Ban on deforestation. Encouraging forest replantation

programmes. Use carefully the fertilizers & pesticides

preferable in optimal dose.