CONTAMINATION OF SOILS WITH ORGANIC AND INORGANIC POLLUTANTS By MASHOOQ HUSSAIN ODHANO (PhD, Student)
Soil contaminationSoil contamination is the occurrence of pollutants in soilabove a certain level causing a deterioration or loss ofone or more soil functions. Also, Soil Contamination canbe considered as the presence of man-made chemicalsor other alteration in the natural soil environment. Thistype of contamination typically arises from the rupture ofunderground storage tanks, application of pesticides,percolation of contaminated surface water to subsurfacestrata, leaching of wastes from landfills or directdischarge of industrial wastes to the soil. The mostcommon chemicals involved are petroleumhydrocarbons, solvents, pesticides, lead and other heavymetals. The occurrence of this phenomenon is correlatedwith the degree of industrialization and intensity ofchemical 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.
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 countryof the world, having a population of more the180 million. It is developing country with anincreasing population density in order todevelop its economy, Pakistan requiresestablishment of new industries. Due tounplanned industrial growth, much of the landand nearby water bodies are polluted byindiscriminate dumping of solid and liquidwastes generated by these units increased levelsof metal ions and organic pollutants in theenvironment are either due to absence of lawsfor various industries to treat their wastes .
The rapid increase in population, together with theunplanned disposal of effluent from tanneries andtextile industries have increased the threat of soilpollution in Pakistan. Faisalabad Effect of industrialeffluents discharged by various industries in theindustrial area o f Lahore, Sheikhupura and Kala ShahKaku indicated soil and water contamination of salts andheavy metals in their respective areas. Environmentalprotection agency studies have been shown thatindustrial effluents from electroplating and tanneryindustries containing toxic metals, such as Cr, Ni, As,Hg, Cu, Pt, etc have contaminated soil and biota of theseareas by such metals in Faisalabad and Lahore. Pakistanreported that Faisalabad city effluent, comprising ofdomestic 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 DISORDERSB. CADMIUM: UNCOUPLER OF OXIDATIVE PHOSPHORYLATIONC. BERYLLIUM :PHOSPHATE INHIBITORD.STRONTIUM :COMPETITOR FOR CALCIUM IN BONELead, Arsenic, Mercury, and Cadmium (all main industrial pollutants) tend toaccumulate in the human body for long periods of time, as they are difficult toflush 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
p0llutantsExcess use of fertilizers Excess use of Na, Mg, Ca, K, Zn, in the form of fertilizers & pesticides inhabit plant growth & reduce crop yield.
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 upthe 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.