UNIT – 5.pptx EVS ENVIROEMENTL STUDIES NOTES
- 1. UNIT – 5 Environmental Pollution Types, causes, effects and controls; Air, water, soil, chemical and noise pollution • Nuclear hazards and human health risks • Solid waste management: Control measures of urban and industrial waste.. • Pollution case studies.
- 5. Types of Pollution Air Pollution Water Pollution Noise Pollution Soil Pollution Chemical Pollution
- 7. Soil Pollution: Soil Pollution is the contamination of soil with solid waste, acid rain, excess of fertilizers, insecticides and herbicides. Soil contamination is caused by the presence of xenobiotic (human made) chemicals or other alteration in the natural soil environment.
- 9. Types of soil pollution: BIOLOGICAL AGENT: Biological agents work inside the soil to introduce manures and digested sludge (coming from the human, bird and animal excreta) into the soil. AGRICULTURAL PRACTICES The soil of the crops is polluted to a large extent with pesticides, fertilizers, herbicides, slurry, debris, and manure RADIOACTIVE POLLUTANTS Radioactive substances such as Radium, Thorium, Uranium, Nitrogen, etc. can infiltrate the soil and create toxic effects. URBAN WASTE Urban waste consists of garbage and rubbish materials, dried sludge and sewage from domestic and commercial waste INDUSTRIAL WASTE Steel, pesticides, textiles, drugs, glass, cement, petroleum, etc. are produced by paper mills, oil refineries, sugar factories, petroleum industries and others as such.
- 10. Examples for Soil contamination: There is a large variety of pollutants that could poison the soil. Examples of the most common and problematic soil pollutants can be found below. LEAD (PB) Potential sources: lead paint, mining, foundry activities, vehicle exhaust, construction activities, agriculture activities MERCURY (HG) Potential sources: mining, incineration of coal, alkali and metal processing, medical waste, volcanoes and geologic deposits, accumulation in plants & vegetables grown on polluted soils ARSENIC (AS) Potential sources: mining, coal-fired power plants, lumber facilities, electronics industry, foundry activities, agriculture, natural accumulation
- 11. ZINC (ZN) Potential sources: mining; foundry activities; construction activities NICKEL (NI) Potential sources: mining; foundry activities; construction activities COPPER (CU) Potential sources: mining, foundry activities; construction activities PAHS (POLYAROMATIC HYDROCARBONS) Potential sources: coal burning, vehicle emissions, accumulation in plants & vegetables grown on polluted soils; cigarette smoke; wildfires, agricultural burning; wood burning, constructions HERBICIDES/INSECTICIDES Potential sources: Agriculture activities, Gardening
- 12. Causes for soil pollution Deforestation Landfills Mining Over gazing Irrigation Toxic fertilizers and pesticides Soil erosion Acid rain Change in climate
- 13. Impact Human health Environment impact Distraction for tourist Inferior Crop Quality Effect on wildlife Global warming Bio magnification.
- 15. Remedies Awareness among people Garbage disposal Say no to plastic Waste management Grow more trees Use of correct farming techniques Proper disposal method of household and industrial waste Proper maintenance of sewage system
- 18. Definition Air pollution can be defined as the presence of toxic chemicals or compounds (including those of biological origin) in the air, at levels that pose a health risk. In an even broader sense, air pollution means the presence of chemicals or compounds in the air which are usually not present and which lower the quality of the air or cause detrimental changes to the quality of life (such as the damaging of the ozone layer or causing global warming).
- 19. Causes Air pollution is probably one of the most serious environmental problems confronting our civilization today. Most often, it is caused by human activities such as Mining Construction Transportation Industrial work Agriculture Smelting, etc. However, natural processes such as Volcanic eruptions Wildfires may also pollute the air
- 20. Types of Air Pollutants A large number of contaminants may pollute the air in a large variety of forms. SULFUR OXIDES (SOX) Toxic gases produced by the volcanic activity, industrial processes, and burning of fossil fuels. NITROGEN OXIDES (NOX) Toxic gases. CARBON MONOXIDE (CO) Extremely toxic, produced by incomplete combustion and vehicle exhaust. CARBON DIOXIDE (CO2) Not toxic, but may dislocate oxygen and produce death through asphyxiation. Additionally, it is a greenhouse gas, emitted by combustion processes, microbial activity, plant respiration.
- 21. VOCS (VOLATILE ORGANIC COMPOUNDS) Toxic and carcinogenic, generated through many human activities such as industrial processes and waste disposal. PARTICULATE MATTER (PM) PM of volcanoes and wildfires, also produced by fossil fuels, mining, foundries, etc. HG IN GASEOUS FORM Results from industrial processes, mining, foundry activities, and other processes RADIOACTIVE POLLUTANTS Produced through radioactive decay and nuclear explosions, war explosions, etc. AMMONIA (NH3) Usually emitted from agricultural processes.
- 29. DEFINITION Water pollution is defined as the presence in groundwater of toxic chemicals and biological agents that exceed what is naturally found in the water and may pose a threat to human health and/or the environment. Additionally, water pollution may consist of chemicals introduced into the water bodies as a result of various human activities. Any amount of those chemicals pollutes the water, regardless of the harm they may pose to human health and the environment. Water pollution affects plants and organisms living in these bodies of water. In almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities.
- 32. Types of water pollution Point source pollution: If pollution comes from a single location, such as a discharge pipe attached to a factory. An oil spill from tanker, a discharge from a smoke stack, or someone pouring oil from their car down a drain. Non point source pollution: A great deal of water pollution happens not from one single source but from many different scattered sources. This is called non point source pollution.
- 34. Crude oil and various petroleum products (including gasoline, diesel fuel, kerosene, motor and lubricating oils, jet fuel). These compounds are lighter than water and thus always sit on top of water forming sheens of “free product”. However, part of these compounds dissolve in water and, even in small amounts may be harmful and at the same time may remain unnoticeable by the eye. Fertilizers (including nitrates and phosphates) – while small amounts are useful to life, higher amounts of nitrates and phosphates in water are only beneficial to algae and harmful microorganisms and are poisonous to human and aquatic life. These contaminants cannot be seen themselves in water (as they do not form sheens or color the water), but their effects can. The typical effect of water pollution by fertilizers (usually through agricultural runoff) is the fast and abundant water growth. Types of water contaminates
- 35. Chlorinated solvents (including TCE, PCE, 1,1,1-TCA, carbon tetrachloride, Freons) which sink in water (are denser than water) and are quite persistent and toxic. These compounds thus, cannot be seen by the eye, in contrast with petroleum products that are easily seen as sheens on top of water surface. Petroleum solvents (including benzene, toluene, xylenes, ethylbenzene) Other organic solvents and chemicals (such as acetone, methyl ethyl ketone, alcohols such as ethanol, isopropanol; or oxygenate compounds such as MTBE) Antibiotics and other pharmaceutical products; Perchlorate – perchlorate salts are used in rocket fuels, as well as many other applications such as fireworks, explosives, road flares, inflation bags, etc. This contaminant is usually associated with military bases, construction sites (when explosives are used). However, natural formation in arid areas may account for perchlorate in water, too (e.g., in Chile, Texas or California where natural formation of perchlorate has been observed)
- 36. Trihalomethanes – these are usually byproducts of water chlorination and may pollute groundwater and surface water via leaking sewer lines and discharges. Examples of such compounds are: chloroform, bromoform, dichlorobromomethane; Metals and their compounds – of higher health risk are the organo-metal compounds which may form when metals from water react with organic compounds from water. Common examples include Hg, As, and Cr poisoning of water. Thus, if water is polluted with both metals and organic compounds the health risk is higher. And so is the effect of water pollution on aquatic life. Pesticides/insecticides/herbicides – comprise a large number of individual chemicals that get into water due to agricultural activities directly (by spraying over large areas) or indirectly with agriculture runoff. The insecticide DDT is a typical example of such type of water pollutant.
- 37. PCBs – in spite of their recent ban, their ubiquitous environmental presence makes these contaminants usually associated with urban runoffs. II) Radiological – when radioactive materials are the water pollutant causes. III) Biological – when various microorganisms (e.g., bacterial species and viruses), worms, and/or algae occurring in a large number are the water pollution causes. This type of pollution is caused by decaying organic material in water, animal wastes, as well as improper disposal of human wastes.
- 38. Causes for water pollution Marine dumping Industrial waste Sewage Households Nuclear waste Oil pollution Underground storage leaks
- 39. Impact of water pollution Death of aquatic animals Disruption of food chains pollution Diseases Destruction of ecosystem
- 40. Solution to water pollution Do not throw away waste in open field Use water wisely Do not throw chemicals, oils, paints, and medicines down the sink drain or toilet. If you see chemicals and pesticides be mindful not overuse. Use of environment friendly liquids and other items Grow trees near a water source Develop awareness among people regarding the importance of water.
- 45. Definition Noise pollution, unwanted or excessive sound that can have deleterious effects on human health and environmental quality. Noise pollution is commonly generated inside many industrial facilities and some other workplaces, but it also comes from highway, railway, and airplane traffic and from outdoor construction activities.
- 47. Type of pollution street traffic sounds from cars, buses, pedestrians, ambulances etc. construction sounds like drilling or other heavy machinery in operation airports, with constant elevated sounds from air traffic, i.e. planes taking off or landing workplace sounds, often common in open-space offices constant loud music in or near commercial venues industrial sounds like fans, generators, compressor, mills train stations traffic household sounds, from the television set to music playing on the stereo or computer, vacuum cleaners, fans and coolers, washing machines, dishwashers, lawnmowers etc. events involving fireworks, firecrackers, loudspeakers etc. conflicts generate noise pollution through explosions, gunfire etc. The dysfunctions, in this case, are likely caused by the conflict and insecurity and less by the noise pollution in itself, although that compounds stress levels too.
- 49. Human Diseases Caused by Noise Pollution Whether we realize we are subjected to it or not, noise pollution can be hazardous to our health in various ways. Hypertension is, in this case, a direct result of noise pollution caused elevated blood levels for a longer period of time. Hearing loss can be directly caused by noise pollution, whether listening to loud music in your headphones or being exposed to loud drilling noises at work, heavy air or land traffic, or separate incidents in which noise levels reach dangerous intervals, such as around140 dB for adult or 120 dB for children. Sleep disturbances are usually caused by constant air or land traffic at night, and they are a serious condition in that they can affect everyday performance and lead to serious diseases. Child development. Children appear to be more sensitive to noise pollution, and a number of noise-pollution-related diseases and dysfunctions are known to affect children, from hearing impairment to psychological and physical effects. Also, children who regularly use music players at high volumes are at risk of developing hearing dysfunctions. In 2001, it was estimated that 12.5% of American children between the ages of 6 to 19 years had impaired hearing in one or both ears Various cardiovascular dysfunctions. Elevated blood pressure caused by noise pollution, especially during the night, can lead to various cardiovascular diseases. Dementia isn’t necessarily caused by noise pollution, but its onset can be favored or compounded by noise pollution. Psychological dysfunctions and noise annoyance. Noise annoyance is, in fact, a recognized name for an emotional reaction that can have an immediate impact.
- 50. Effects of Noise Pollution on Wildlife and Marine Life Our oceans are no longer quiet. Thousands of oil drills, sonars, seismic survey devices, coastal recreational watercraft and shipping vessels are now populating our waters, and that is a serious cause of noise pollution for marine life. Whales are among the most affected, as their hearing helps them orient themselves, feed and communicate. Noise pollution thus interferes with cetaceans’ (whales and dolphins) feeding habits, reproductive patterns and migration routes, and can even cause hemorrhage and death. Other than marine life, land animals are also affected by noise pollution in the form of traffic, firecrackers etc., and birds are especially affected by the increased air traffic.
- 51. Social and Economic Costs of Noise Pollution The World Health Organization estimates that one out of three people in Europe is harmed by traffic noise. More than the purely medical effects of noise pollution on the individual, there is a significant social and economic impact. Since noise pollution leads to sleep disturbance, it affects the individual’s work performance during the day, it leads to hypertension and cardiovascular disease and costs the health system additional time and money, and it negatively affects school performance in children.
- 52. Solution
- 54. Small note on Decibles (dB) We measure sound intensity (also referred to as sound power or sound pressure) in units called decibels. Decibels (dB) are named in honor of Alexander Graham Bell, the inventor of both the telephone and the audiometer. An audiometer is a device that measures how well a person can hear certain sounds. A modern version of it is still used today to diagnose hearing loss.
- 55. How loud are some common sounds in decibel measurements? ear-total silence - 0 dB •A whisper - 15 dB •A library - 45 dB •A normal conversation - 60 dB •A toilet flushing 75-85 dB •A noisy restaurant - 90 dB •Peak noise on a hospital ward - 100dB •A baby crying - 110 dB •A jet engine - 120 dB •A Porsche 911 Carrera RSR Turbo 2.1 - 138 dB (see YouTube video of Porsche car noise tests using the Pulsar Nova Sound Level Meter) •A balloon popping - 157 dB
- 56. Even small increases in dBA level can have a big impact on your hearing health. As dBA rises, your hearing is more likely to be damaged, and more quickly than you might expect. Sound is more likely to damage your hearing if it is: •85 dBA and you are exposed to it for at least 8 hours. •100 dBA and you are exposed to it for at least 14 minutes. •110 dBA and you are exposed to it for at least 2 minutes. You can measure sounds in dBA yourself with a sound level meter, such as this app made by the National Institute for Occupational Safety and Health. The app can measure sounds from 0 dBA (sounds so quiet you can barely hear them) to whispering (30 dBA), normal conversation (60-70 dBA), and even a jet taking off (140 dBA). Just remember to turn down the volume, move away from the noise, or wear hearing protectors, especially when the sound level is at or about 85 dBA!
- 58. DEFINITION Chemical pollution is defined as the presence or increase in our environment of chemical pollutants that are not naturally present there or are found in amounts higher than their natural background values. Most of the chemicals that pollute the environment are man-made, resulted from the various activities in which toxic chemicals are used for various purposes.
- 59. The Effects of Chemical Pollution Chemical pollution can be caused by a variety of chemicals from a variety of sources and can involve a variety of health effects from simple digestive problems to chemical intoxication and sudden death by poisoning. The effects are usually related to the exposure to high amounts of chemicals. Chemical pollution leads to various serious diseases, generally by consuming poisonous food, drinking highly contaminated water, or breathing highly contaminated air. Chemical intoxication can have severe health effects that may trigger immediate symptoms and diseases or delayed effects which may appear after weeks or months since the exposure occurred. This is based on the type of pollutants and on the amounts to which you are exposed. CAUTION, never assume that all is OK if no health effects appear immediately! Various chemical pollutants may accumulate in the aquatic sediments over longer periods of time. This means that, if no tests are performed, chemical pollution in the ocean water could pose serious health risks to the ecosystem and ultimately could cause mild or deadly chemical intoxication in humans after the consumption of contaminated fish or seafood. However, there are prevention tips you can follow to minimize exposure to chemical pollution.
- 60. Remedies Recycle, reuse or donate liquids from automobiles. Do not pour them down the drain or throw them away in the regular trash. Limit the use of your cars and motor vehicles. Riding a bike or taking public transportation will help reduce the amount of chemicals put into the air.
- 61. Nuclear hazards and human health risks
- 62. Nuclear hazards and human health risks According to International Atomic Energy Agency (IAEA), a nuclear and radiation accidents/ hazards is an event that has led to significant consequences to people, the environment or the facility. Nuclear hazards. Risk or danger to human health or the environment exposed by the radiation emanating from the atomic nuclei is called as nuclear hazard. Nuclear hazard is an actual or potential release of radioactive material at a commercial nuclear power plant or a transportation accident
- 63. Radiations are the waves of energy that travels and spread all around in our environment. These radiations are useful as well harmful for us. Examples include visible light, radio waves, microwaves, infrared and ultraviolet lights, X-rays, and gamma-rays, etc. Radionuclides are elements (uranium 235, uranium 283, thorium 232, potassium 40, radium 226, carbon 14 etc) with unstable atomic nuclei and on decomposition release ionizing radiations in the form of alpha, beta and gamma rays. Out of the known 45O radioisotopes only some are of environmental concern like strontium 90, tritium, plutonium 239, argon 41, cobalt 60, cesium 137, iodine 131, krypton 85 etc.
- 64. What is alpha, beta and gamma? The alpha particles are fast moving positively charged particles whereas beta particles are high speed negatively charged electrons. These ionization radiations have variable penetration power. Alpha particles can be interrupted by a sheet of paper while beta particles can be blocked by a piece of wood or a few millimeters of aluminum sheet. The gamma rays can pass through paper and wood but can be stopped by concrete wall, lead slabs or water. alpha (α), beta (β), and gamma (γ)
- 65. Sources of Radioactivity Various sources of radioactivity can be grouped into two broad categories Natural sources : Sources of natural radioactivity include cosmic rays from outer space, radioactive radon-222, soil, rocks, air, water and food, which contain one or more radioactive substances. Anthropogenic sources: These sources are nuclear power plants, nuclear accidents, X-rays, diagnostic kits, test laboratories etc. where radioactive substances are used
- 66. RADIATIONS THAT CAUSE POLLUTION 1. Electromagnetic radiations: UV rays X-rays Gamma rays Infrared rays Radio waves 2. Particulate radiations Beta, alpha particles etc
- 67. Impacts of Nuclear Radiation SHORT TERM RECOVERABLE EFFECTS Short term affect on skin, hair loss, lungs and on reproductive organs LONG TERM IRRECOVERABLE EFFECTS Radiation sickness A person's risk of getting sick depends on how much radiation the body absorbs. Radiation sickness is often fatal and can produce such symptoms as bleeding and shedding of the lining on the gastrointestinal tract. Bone marrow death is caused by a dose of radiation between 2 and 10 Gray and is characterized by the part of the bone marrow that makes the blood being broken down. Therefore, production of red and white blood cells and platelets is stopped due to loss of the blood-making stem cells Cataract induction Cancer induction Infectious diseases resulting from nuclear attack such as dysentery, tuberculosis, cholera, pneumonia etc. GENETIC The effect is suffered by the offspring of the individual exposed. Mutations of these reproductive cells are passed to the offspring of the individual exposed.
- 68. Control of Radiation/Nuclear Pollution a. Siting of nuclear power plants should be carefully done after studying long term and short term effects. b. Proper disposal of wastes from laboratory involving the use of radioisotopes should be done. c. Workers in nuclear plants should be provided with nuclear gadgets and safety measures against accidents. d. Leakage of radioactive elements from nuclear reactors, laboratories, transport, careless handling and use of radioactive fuels should be checked. e. Level of radiation pollution should be monitored regularly in risk areas. f. Disposal of radioactive wastes should be done with special attention.
- 70. What is waste Waste is also referred to as rubbish, trash, garbage, or junk depending upon the type of material and the regional terminology. In living organisms, waste relates to unwanted substances or toxins that are expelled from them.
- 71. What is Solid Waste Management? Solid waste management is a term that is used to refer to the process of collecting and treating solid wastes. It also offers solutions for recycling items that do not belong to garbage or trash. As long as people have been living in settlements and residential areas, garbage or solid waste has been an issue. Waste management is all about how solid waste can be changed and used as a valuable resource.
- 72. Categories of Waste Organic waste: Kitchen waste, waste from food preparation, vegetables, flowers, leaves, fruits, and market places. Combustibles: Paper, wood, dried leaves, packaging for relief items etc. that are highly organic and having low moisture content. Non-combustibles: Metal, Tins, Cans, bottles, stones, etc. Toxic waste: Old medicines, paints, chemicals, bulbs, spray cans, fertilizer and pesticide containers, batteries, shoe polish. Recyclables: Paper, glass, metals, plastics. Ashes or Dust: Residue from fires that are used for cooking. Construction waste: Rubble, roofing, broken concrete etc. Hazardous waste: Oil, battery acid, medical waste, industrial waste, hospital waste. Dead animals: Carcasses of dead livestock or other animals. Bulky waste: Tree branches, tires etc. Soiled waste: Hospital waste such as cloth soiled with blood and other body fluids.
- 75. The types of litter and their approximate degeneration time Type of litter Approximate time taken to degenerate the litter Organic waste such as vegetable and fruit peels, leftover foodstuff, etc. A week or two. Paper 10–30 days Cotton cloth 2–5 months Wood 10–15 years Woolen items 1 year Tin, aluminum, and metal cans 100–500 years Plastic bags One million years? Glass bottles undetermined
- 76. Objectives Public hygiene and health Reuse, reduce and recycle Energy generation Sustainable development Aesthetics
- 77. Various Sources of Solid Waste Every day, tonnes of solid waste are disposed of at various landfill sites. This waste comes from homes, offices, industries and various other agricultural related activities. These landfill sites produce foul smell if waste is not stored and treated properly. It can pollute the surrounding air and can seriously affect the health of humans, wildlife and our environment. The following are major sources of solid waste:
- 78. 1. Residential Residences and homes where people live are some of the major sources of solid waste. The garbage from these places includes food wastes, plastics, paper, glass, leather, cardboard, metals, yard wastes, ashes and special wastes like bulky household items such as electronics, tires, batteries, old mattresses and used oil. Most homes have garbage bins where they can throw away their solid wastes in and later, the bin is emptied by a garbage collecting firm or person for treatment. 2. Industrial Industries are known to be one of the biggest contributors to solid waste. They include light and heavy manufacturing industries, construction sites, fabrication plants, canning plants, power and chemical plants. These industries produce solid waste in the form of housekeeping wastes, food wastes, packaging wastes, ashes, construction and demolition materials, special wastes, medical wastes as well as other hazardous wastes. 3. Commercial Commercial facilities and buildings are yet another source of solid waste today. Commercial buildings and facilities, in this case, refer to hotels, markets, restaurants, godowns, stores and office buildings. Some of the solid wastes generated from these places include plastics, food wastes, metals, paper, glass, wood, cardboard materials, special wastes and other hazardous wastes.
- 79. 4. Institutional The institutional centers like schools, colleges, prisons, military barracks and other government centers also produce solid waste. Some of the common solid wastes obtained from these places include glass, rubber waste, plastics, food wastes, wood, paper, metals, cardboard materials, electronics as well as various hazardous wastes. 5. Construction and Demolition Areas Construction and demolition sites also contribute to the solid waste problem. Construction sites include new construction sites for buildings and roads, road repair sites, building renovation sites and building demolition sites. Some of the solid wastes produced in these places include steel materials, concrete, wood, plastics, rubber, copper wires, dirt and glass. 6. Municipal Services The urban centers also contribute immensely to the solid waste crisis in most countries today. Some of the solid waste brought about by the municipal services include street cleaning, wastes from parks and beaches, wastewater treatment plants, landscaping wastes and wastes from recreational areas, including sludge.
- 80. 7. Treatment Plants and Sites Heavy and light manufacturing plants also produce solid waste. They include refineries, power plants, processing plants, mineral extraction plants and chemical plants. Among the wastes produced by these plants, there are industrial process wastes, unwanted specification products, plastics, metal parts, just to mention a few. 8. Agriculture Crop farms, orchards, dairies, vineyards and feedlots are also sources of solid wastes. Among the wastes they produce are agricultural wastes, spoiled food, pesticide containers and other hazardous materials. 9. Biomedical This refers to hospitals and biomedical equipment and chemical manufacturing firms. In hospitals, there are different types of solid wastes produced. Some of these solid wastes include syringes, bandages, used gloves, drugs, paper, plastics, food wastes and chemicals. All these require proper disposal or else they will cause a huge problem for the environment and the people in these facilities.
- 81. Effects of Poor Solid Waste Management Litter Surroundings Impact on human health Disease-causing pests Environmental problem Soil and groundwater pollution Emission of toxic gases Impact on land and aquatic animals
- 82. Methods of Solid Waste Management There are different methods of solid waste management. The following are some of the recognized methods: Sanitary landfill Incineration Recovery and recycling Composting Pyrolysis
- 88. Waste Management Policies Environment protection act, 1986 Hazardous waste rule, 1989 Bio-medical waste rule, 1998 Municipal solid waste rule, 2000 Waste management act, 1996 Solid waste policy in India, 2006
- 90. References: https://www.environmentalpollutioncenters.org/soil/ https://www.environmentalpollutioncenters.org/air/ https://www.environmentalpollutioncenters.org/water/ https://www.environmentalpollutioncenters.org/noise-pollution/ https://www.environmentalpollutioncenters.org/chemical/ http://www.aurobindo.du.ac.in/uploads/pdf/1587784576_EVS_Nuclear_hazar ds_and_human_health_risks.pdf https://www.conserve-energy-future.com/sources-effects-methods-of-solid- waste-management.php https://www.slideshare.net/amitnakli/final-ppt-36453248?next_slideshow=1