GREEN GREETINGS…

ENVIRONMENTAL STUDIES UNIT V AIR POLLUTION WATER POLLUTION SOIL POLLUTION

Introduction POLLUTANT : Any physical, chemical or biological agent that in its sheer presence has impact on environment that makes a particular resource useless for its designated use. POLLUTION is a situation where pollutants bring undesirable changes in the environment. SOURCES of pollutant : Natural sources Anthropogenic/ Man made sources EFFECTS CONTROL MEASURES

AIR POLLUTION AIR POLLUTION : Air Pollution may be broadly be defined as the presence of one or more contaminants like dust, smoke, mist, odor in the atmosphere which are injurious to human beings, plants and animals or which unreasonably obstruct life and property. Air Pollution may be described as “ The imbalance in quality of air so as to cause adverse effects on the living organisms on earth”. COMPOSITION OF AIR : Atmosphere is gaseous envelope surrounding the earth which constitutes Major gases (N2, O2, CO2), Minor gases (He, ) and Trace gases (SO2, CO, CH4). Based on Temperature changes Air environment is divided into 4 segments Troposphere (Altitude range is 0 to 11Kms) Stratosphere (11 to 50kms) Mesosphere (50 to 85kms) Ionosphere (85 to 100kms)

Types of Air pollutants Air Pollutants are of two types, Primary and Secondary pollutants based on the source. Primary pollutants are directly emitted from the source. e.g., SO2, CO2 etc., Secondary pollutants are resulted from environmental reactions. e.g NO3, H2SO4 etc., Particulates include Aerosols, Mist. Dust, Smoke, fumes, fog and smog.

Sources of Air Pollution Air pollutants are substances causing damage to animals, plants, building material which is adversely affected by pollutants. Major Sources of Air Pollution Natural Sources : Volcanic eruptions – poisonous gases such as SO2, H2S, CO etc. Forest fires - H2S, CH4 etc. Evapo transpiration process – CO2 Oxidation process – natural photochemical reactions Man made sources/Anthropogenic Sources include Population explosion – emission of GHG’s result in global warming Deforestation – imbalance of CO2 and O2 in the nature Burning of fossil fuels – combustion process Emission from transportation sector – Automobile exhausts result in PCS Rapid Industrialization – Power plants, Smelters, refineries etc. Agricultural activities – pesticides, insecticides, herbicides etc.

Effects of Air Pollution Pollutants are generally classified as Gaseous pollutants, Particulate pollutants, Aerosols, Radioactive pollutants. Gaseous pollutants – CO2, CO, SOx, NOx, Hydro carbons Carbon dioxide Traps heat in the atmosphere result in Global warming Carbon monoxide Harmful to humans, affects respiration, cardiac and pulmonary functions SOx :Oxides of Sulphur Acid rains wash away nutrients, necrosis on leaves bronchitis, emphysema and psychological disorders in humans Effects on materials,Stone leprosy: H2SO4 corrodes on marble monuments NOx :Oxides of Nitrogen Toxic produces irritating effect, affects lungs – bronchitis, emphysema. chlorosis effects and decreased photosynthetic activity in plants. Hydro carbons React with NO to form secondary pollutants, Photo Chemical Smog Particulate pollutants (fumes, dust, smoke etc) Toxic mist, chronic non specific diseases, soil corrosion. Aerosols Air pollutants remain suspended in air Radioactive Pollutants Cellular damage in man and animals

Control Strategies Control of NOx pollution : Removal of NOx by catalytic decomposition and Scrubbing process Discharge of gaseous pollutants by building higher smoke stacks (vent) Control of SOx pollution : Removal of Sulphur from fuel before burning, and using sorption methods. Control of CO pollution : Exhaust gas analyzers to check emissions Vehicular pollution can be controlled by upgrading fuel quality, using catalytic convertors. Control of Hydro carbons : Incineration, adsorption, absorption and condensation Control of particulate matter : Cyclones, electrostatic precipitators, filters etc. Reforestation programs

WATER POLLUTION Water is elixir of life. Water pollution is defined as the alteration of physical, chemical and biological characteristics of water resulting in harmful effects on life systems. Characteristics of water Types of water pollution : Ground water pollution Surface water pollution Lake, River and Sea water pollution.

Sources of Water Pollution Major sources are divided into Natural and Man made Natural Sources: Eutrophication process Floods Man made sources: Sewage and domestic wastes Toxic metals Industrial effluents Agricultural discharges Detergents, pesticides Siltation process

Effects of Water Pollution Sewage and domestic wastes effect human health resulting diseases such as cholera, typhoid, dysentery Industrial discharges contain Lead, arsenic, Mercury, Cadmium etc., which pose deleterious impacts in life systems Lead – damages liver and kidney Arsenic – lung cancer, ulcers in gastro intestinal tract Cadmium – diarrhea, kidney cysts, bone deformation etc Mercury – Neurological disorders Agricultural discharges include fertilizers, pesticides which are toxic to both aquatic and human life. .

Control Strategies Sewage treatment plants Integrated approach and organic farming Ideal maintenance of plant upkeep in Industries Management and legislation – CPCB Water treatment Primary treatment involves coagulation and flocculation Secondary treatment involves disinfection process Information dissemination through sensitization programs.

SOIL POLLUTION Soil is the uppermost weathered layer of earth’s crust and is a significant ecological factor in sustenance of biosphere. SOURCES OF SOIL POLLUTION: Natural Erosion – wind, water Man made Industrial Wastes Urban wastes Agricultural wastes Radioactive wastes Mining

Effects and control of Soil Pollution These pollutants affect and alter the chemical and biological properties of the soil, as a result these toxic elements enter into human food chain from soil or water and finally pose deleterious effects on living organisms – biomagnification process. Control Strategies : Check dams/ Rock filled dams Trenches Organic farming