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Air pollution

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  1. Air pollution Supervision Prof. Dr. Mervat Salah

  2. Outcomes 1-To know the meaning of air pollution 2-To differentiate between outdoor and indoor pollution 3-To know types of air pollution 4-To understand the ways to control air pollution

  3. AIR POLLUTION Type of pollution:- outdoor pollution – indoor pollution Sources of out doorpollution • Combustion of fuel (natural gas, petroleum, coal and wood) • Industrial process • Natural process (Volcanic)

  4. Types of Major Air Pollutants Carbon oxides (CO) Nitrogen oxides and nitric acid (NO, HNO3) Sulfur dioxide and sulfuric acid (SO2, H2SO4) Particulates (SPM) Ozone (O3) Volatile organic compounds (VOCs) )

  5. Pollutants Pollutants can be classified as either primary or secondary - Primary pollutants are substances directly emitted from a process, such as the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories. - Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary pollutant is ground level ozone

  6. Sources and Types of Air Pollutants

  7. Environmental challenges • Green house effect: Increasing global temperature. Scientists predicting that earth's temperature will increase by 3-40C by year 2030 if the pollution continues to increase at the same pace. • Ozone depletion: As ozone layer in the upper atmosphere absorbs incoming harmful ultraviolet radiation but it is now getting thinner & more UVs are reaching in to earth creating different disease like cancer& eye problems. • Photochemical smog: In 1952 London was covered by smog for 10 days .This smog was caused by fog, smoke, ash,& SO2 plus NO2.Sunlight played a great role in the formation of this smog . Acid rain: is caused by oxides of nitrogen & sulphur. It increases acidity of soil & effects the growth of trees & plants.

  8. Acid Deposition • Sulfur dioxides and nitrogen oxides • Wet and dry deposition • Acid rain • Regional air pollution • Midwest coal-burning power plants • Prevailing winds

  9. Acid Deposition Wind Transformation to sulfuric acid (H2SO4) and nitric acid (HNO3) Windborne ammonia gas and some soil particles partially neutralize acids and form dry sulfate and nitrate salts Wet acid deposition (droplets of H2SO4 and HNO3 dissolved in rain and snow) Nitric oxide (NO) Sulfur dioxide (SO2) and NO Dry acid deposition (sulfur dioxide gas and particles of sulfate and nitrate salts) Acid fog Lakes in shallow soil low in limestone become acidic Lakes in deep soil high in limestone are buffered Fig. 15-4, p. 351

  10. Effects Of Pollution • Respiratory diseases in humans • Toxic metal leaching • Structural damage • Kills fish and other aquatic organisms • Leaches plant nutrients from soil • Acid clouds and fog at mountaintops

  11. + water SO2 & NOX Acid Rain Solar Radiation H2SO4 (Sulphuric Acid) HNO3 (Nitric Acid) Acid Rain Factories, Transportation Lake Sea SEA

  12. The Greenhouse Effect • Earth’s natural greenhouse effect • Natural greenhouse gases • Water vapor (H2O) • Carbon dioxide (CO2) • Methane (CH4) • Nitrous Oxide (N2O) • Enhanced greenhouse effect • Global warming

  13. Effect of Global warming • Rise in average global surface temperature • Changes in glaciers, rainfall patterns, hurricanes • Droughts and floods. Threat to biodiversity • Decreased food production • Diseases (Threats to human health) • Economic and social disruption • Rising sea levels • Extreme weather

  14. Government Roles in Reducing the Threat of Climate Change (1) • Regulate carbon dioxide as a pollutant • Carbon taxes • Cap total CO2 emissions • Subsidize energy-efficient technologies • Technology transfers

  15. Photochemical reactions • Photochemical smog • Brown-air smog • Sources • Climate effects • Urban areas Photochemical Smog

  16. Earth A Green House Effect Methane Carbon Dioxide Nitrous oxide Ozone Earth This natural balance may be distorted by Green House Effect as gases such as carbon dioxide have built up in the atmosphere trapping more heat Green house gases in natural condition insulates the earth against extreme of temperature by limiting both incoming solar radiation & escape of reradiated heat in to space. Contribution of different gases to cause green house effect Less reradiated heat escapes in to space Some reradiated heat escapes in to space sun sun sun More reradiated heat reflected back to earth Infra-red radiation Some reradiated heat reflected back to earth Surface Temperature increases Surface Temperature normal Atmosphere Atmosphere Unbalanced Green House Effect Naturally Moderated Green House Effect

  17. NO2 Nitrogen dioxide H2O Water Hydrocarbons Ultraviolet Radiation NO Nitric Oxide O2 Molecular Oxygen O Atomic Oxygen O3 Ozone HNO3 Nitric Acid PANs Peroxyacyl nitrates Aldyhydes (e.g. Formaldehyde) Photochemical Smog Formation of Photochemical Smog

  18. Ozone Layer thinning • Affect on seasonal changes • Causes – chlorofluorocarbons (CFCs) that uses in: • Coolants in air conditioners and refrigerators • Propellants in aerosol cans • Cleaning solutions for electronic parts • Fumigants • Bubbles in plastic packing foam

  19. Ozone layer depletion ozone Ultraviolet rays from Sun Chlorofluorocarbons are entering in to atmosphere releasing chlorine. The chlorine than break down the ozone The Ozone layer in stratosphere blocks these harmful UV rays Oxygen Whole in Ozone layer chlorine The chlorine released from CFCs break down the ozone molecule. More ultraviolet radiations are reaching in to earths surface as there is a whole in ozone layer.

  20. Reversing Ozone Depletion • Stop producing ozone-depleting chemicals • Slow recovery • Montreal Protocol • Copenhagen Protocol • International cooperation

  21. Indoor air quality Indoor air quality (IAQ) is a term referring to the air quality within and around buildings and structures. IAQ can be affected by microbial contaminants (mold, bacteria), gases (including carbon monoxide, radon, volatile organic compounds),and particulates

  22. Major Indoor Air Pollutants • Tobacco smoke • Formaldehyde • Radioactive radon-222 gas • Very small particles • Sick-building syndrome (SBS) • Developing countries • Indoor cooking and heating

  23. Air Pollution and the Human Respiratory System • Natural protective system • Lung cancer, chronic bronchitis, emphysema, asthma • Premature deaths

  24. Air Pollutants and its impact on human health • Particulate Matter • Dust and smoke particles cause irritation of the respiratory tract and produce bronchitis, asthma and lung diseases. • Dust and smoke function as nuclei for condensation of water vapors and produce smog which attract chemicals like SO2, H2S, NO2,etc. Smog not only reduce visibility but is also harmful due to its contained chemicals.

  25. NOISE POLLUTION The term noise is applied to the sound that cause irritation on hearing of healthy human being. Sources • Transport noise--- Originates from road traffic (vehicular), air craft and rail traffic. • Industrial noise--- It produced by presses; punch and stamp machine, pneumatic drills, milling machines, cutter and routers, dust extractors. etc. • Domestic noise--- It is generated from domestic appliance like washing machines, spin dryers, food mixer, sink waste grinder and vacuum cleaner.

  26. Effects Of Noise Pollution Hearing damage from noise exposure Pathological and Physiological disorders The impact of noise may cause permanent hearing loss due to the exposure to noise levels exceeding 90 dB

  27. What is sick building syndrome ? The feeling of illness among majority of occupants of a conditioned space is called “Sick Building Syndrome”. A variety of illness symptoms reported by occupants in sick buildings are – Headache, fatigue, irritation in eyes, nose and throat, shortness of breathe etc.

  28. What is sick building syndrome ? Causes Inadequate ventilation insufficient supply of outside air; poor mixing; fluctuations in temperature & humidity;

  29. Assignment Side effects of pollution by ozone made by : • Mahmoud RadyAkila • Ahmed Abdeen • Sary Ibrahim • Ahmed Shafiq • SayedGhze Side effects of methan pollution made by: • EmanMohamed Ahmed • Hager Abd el shafiq • HananHelmy Ibrahim

  30. Recommended text book • Basic Environmental Health