UNIT 5: Pollution - UGC

1 111 PollutionUNIT 5 CAUSES, EFFECTS AND CONTROL MEASURES Air Water Soil Marine Noise Thermal Nuclear SOLID WASTE MANAGEMENT: CAUSES, EFFECTS AND CONTROL MEASURESOF URBAN AND INDUSTRIAL ROLE OF INDIVIDUALS IN Pollution Pollution CASE DISASTER MANAGEMENT: FLOODS, EARTHQUAKES, CYCLONES, , 5:09 PM111112 Environmental Studies for Undergraduate Courses We spray our elms, and the following spring,trees are silent of robin song, not becausewe sprayed the robins directly but becausethe poison traveled step by step through thenow familiar elm-earthworm-robin cycle Rachael CarsonThis quotation appeared in Rachael Carson sbook entitled Silent Spring. In the years follow-ing the publication of Silent Spring in 1962, thebook has inspired controversy and has initiateda major change in thinking about the safety ofusing pesticides and other toxic DEFINITIONP ollution is the effect of undesirable changes inour surroundings that have harmful effects onplants, animals and human beings.

2 This , 5:09 PM112113 Pollutionwhen only short-term economic gains are madeat the cost of the long-term ecological benefitsfor humanity. No natural phenomenon has ledto greater ecological changes than have beenmade by mankind. During the last few decadeswe have contaminated our air, water and landon which life itself depends with a variety ofwaste include solid, liquid or gaseous sub-stances present in greater than natural abun-dance produced due to human activity, whichhave a detrimental effect on our nature and concentration of a pollutantdetermines the severity of detrimental effectson human health. An average human requiresabout 12 kg of air each day, which is nearly 12to15 times greater than the amount of food weeat.

3 Thus even a small concentration of pollut-ants in the air becomes more significant in com-parison to the similar levels present in that enter water have the ability tospread to distant places especially in the an ecological perspective pollutants canbe classified as follows:Degradable or non-persistent pollutants: Thesecan be rapidly broken down by natural pro-cesses. Eg: domestic sewage, discarded veg-etables, degradable or persistent pollutants: Pol-lutants that remain in the environment for manyyears in an unchanged condition and take de-cades or longer to degrade. Eg: DDT and pollutants: These cannot bedegraded by natural processes. Once they arereleased into the environment they are difficultto eradicate and continue to accumulate.

4 Eg:toxic elements like lead or CAUSES, EFFECTS AND CONTROL MEA-SURES OF Air PollutionHistory of air Pollution : The origin of air pol-lution on the earth can be traced from the timeswhen man started using firewood as a meansof cooking and heating. Hippocrates has men-tioned air Pollution in 400 BC. With the discov-ery and increasing use of coal, air pollutionbecame more pronounced especially in urbanareas. It was recognized as a problem 700 yearsago in London in the form of smoke Pollution ,which prompted King Edward I to make the firstantipollution law to restrict people from usingcoal for domestic heating in the year 1273. Inthe year 1300 another Act banning the use ofcoal was passed. Defying the law led to imposi-tion of capital punishment.

5 In spite of this airpollution became a serious problem in Londonduring the industrial revolution due to the useof coal in industries. The earliest recorded ma-jor disaster was the London Smog that occurredin 1952 that resulted in more than 4000 deathsdue to the accumulation of air pollutants overthe city for five Europe, around the middle of the 19th cen-tury, a black form of the Peppered moth wasnoticed in industrial areas. Usually the normalPeppered moth is well camouflaged on a cleanlichen covered tree. However the peppered pat-tern was easily spotted and picked up by birdson the smoke blackened bark of trees in theindustrial area, while the black form remainedwell camouflaged.

6 Thus while the pepperedpatterned moths were successful in surviving inclean non-industrial areas, the black colouredmoths were successful in industrial areas. Withthe spread of industrialization, it has been ob-served that the black forms are not only see inPeppered moth, but also in many other is a classic case of Pollution leading to , 5:09 PM113114 Environmental Studies for Undergraduate CoursesAir Pollution began to increase in the beginningof the twentieth century with the developmentof the transportation systems and large-scale useof petrol and diesel. The severe air quality prob-lems due to the formation of photochemicalsmog from the combustion residues of dieseland petrol engines were felt for the first time inLos Angeles.

7 Pollution due to auto-exhaust re-mains a serious environmental issue in manydeveloped and developing countries Air Pollution Control Act in India was passedin 1981 and the Motor Vehicle Act for control-ling the air Pollution , very recently. These lawsare intended to prevent air from being greatest industrial disaster leading to seri-ous air Pollution took place in Bhopal whereextremely poisonous methyl isocyanide gas wasaccidentally released from the Union Carbide spesticide manufacturing plant on the night ofDecember 3rd 1984. The effects of this disasteron human health and the soil are felt even of the atmosphereThe atmosphere is normally composed of 79percent nitrogen, 20 percent oxygen and onepercent as a mixture of carbon dioxide, watervapour and trace amounts of several other gasessuch as neon, helium, methane, krypton, hy-drogen and xenon.

8 The general structure of theatmosphere has several important features thathave relevance to environmental problems. Theatmosphere is divided into several innermost layer the troposphere extends 17kilometers above sea level at the equator andabout 8 kilometers over the poles. It containsabout 75 percent of the mass of the earth s fragility of this layer is obvious from the factthat if the earth were an apple this particularlayer would be no thicker than an apple s declines with altitude in the tro-posphere. At the top of the troposphere tem-peratures abruptly begin to rise. This boundarywhere this temperature reversal occurs is calledthe tropopause marks the end of the tropo-sphere and the beginning of the stratosphere,the second layer of the atmosphere.

9 The strato-sphere extends from 17 to 48 kilometers abovethe earth s surface. While the composition ofthe stratosphere is similar to that of the tropo-sphere it has two major differences. The vol-ume of water vapour here is about 1000 timesless while the volume of ozone is about 1000times greater. The presence of ozone in thestratosphere prevents about 99 percent of thesun s harmful ultraviolet radiation from reach-ing the earth s surface thus protecting humansfrom cancer and damage to the immune sys-tem. This layer does not have clouds and henceairplanes fly in this layer as it creates less turbu-lence. Temperature rises with altitude in thestratosphere until there is another reversal .

10 Thispoint is called the stratopause and it marks theend of the stratosphere and the beginning ofthe atmosphere s next layer, the the mesosphere the temperature decreaseswith altitude falling up to 110 oC at the this is a layer where ionization of thegases is a major phenomenon, thus increasingthe temperature. This layer is called the ther-mosphere. Only the lower troposphere is rou-tinely involved in our weather and hence airpollution. The other layers are not significant indetermining the level of air and sources of Air PollutionWhat is air Pollution ?Air Pollution occurs due to the presence of un-desirable solid or gaseous particles in the air inquantities that are harmful to human health andthe environment.