Air pollution

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This is a presentation for students of 6th and 7th.


<ul><li> 1. Any visible or invisible particle or gasfound in the air that is not part of theoriginal, normal composition are calledair pollutants</li></ul> <p> 2. Natural: forest fires, pollen, duststormUnnatural: man-made; coal, wood andother fuels used in cars, homes, andfactories for energy 3. AQI: Air Quality IndexIndicates whether pollutant levels in air may causehealth concerns.Ranges from 0 (least concern) to 500 (greatestconcern) 4. Air Quality Air Quality Index Protect Your HealthGood 0-50 No health impacts are expected whenair quality is in this range.Moderate 51-100 Unusually sensitive people shouldconsider limiting prolonged outdoorexertion.Unhealthy forSensitive Groups101-150 Active children and adults, and peoplewith respiratory disease, such asasthma, should limit prolonged outdoorexertion.Unhealthy 151-200Active children and adults, and peoplewith respiratory disease, such asasthma, should limit prolonged outdoorexertion, everyone else, especiallychildren should limit prolonged outdoorexertion.Very Unhealthy (Alert) 201-300 Active children and adults, and peoplewith respiratory disease, such asasthma, should limit prolonged outdoorexertion everyone else, especiallychildren, should limit outdoor exertion. 5. 5 M a j o r P o l l u t a n t s :1 . . ) C a r b o n M o n o x i d e2 . ) S u l f u r D i o x i d e3 . ) N i t r o g e n D i o x i d e4 . ) P a r t i c u l a t e M a t t e r5 . ) G r o u n d L e v e lO z o n e 6. CCaarrbboonn MMoonnooxxiiddeecolorless, odorlessproduced when carbon does not burn infossil fuelspresent in car exhaustdeprives body of O2 causing headaches,fatigue, and impaired vision 7. SSuullffuurr DDiiooxxiiddeeproduced when coal and fuel oilare burnedpresent in power plant exhaustnarrows the airway, causingwheezing and shortness of breath,especially in those with asthma 8. NNiittrrooggeenn DDiiooxxiiddeereddish, brown gasproduced when nitric oxidecombines with oxygen in theatmospherepresent in car exhaust andpower plantsaffects lungs and causeswheezing; increases chance ofrespiratory infection 9. PPaarrttiiccuullaattee MMaatttteerrparticles of different sizes andstructures that are released into theatmospherepresent in many sources includingfossil fuels, dust, smoke, fog, etc.can build up in respiratory systemaggravates heart and lung disease;increases risk of respiratory infection 10. GGrroouunndd LLeevveell OOzzoonneeat upper level, ozone shields Earth from sunsharmful UV raysat ground level, ozone is harmful pollutantsformed from car, power and chemical plantexhaustirritate respiratory system and asthma;reduces lung function by inflaming anddamaging lining of lungs 11. Combination of gases with water vapor anddustCombination of words smoke and fogForms when heat and sunlight react withgases (photochemical smog)Occurs often with heavy traffic, hightemperatures, and calm winds 12. 1st smog related deaths were in London in1873; death toll 500 people; can youimagine how much worse the atmosphere isnow?!Limits visibilityDecreases UV radiationYellow/black color over citiesCauses respiratory problems and bronchialrelated deaths 13. The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiatedin all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of theaverage surface temperature above what it would be in the absence of the gases. Solar radiation at the frequencies of visible light largely passes through the atmosphere to warm the planetary surface, which then emits this energyat the lower frequencies of infrared thermal radiation. Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of theenergy to the surface and lower atmosphere. The mechanism is named after the effect of solar radiation passing through glass and warming agreenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside thestructure so that heat is not lost by convection. If an ideal thermally conductive blackbody were the same distance from the Sun as the Earth is, it would have a temperature of about 5.3 C.However, since the Earth reflects about 30% of the incoming sunlight, this idealized planet's effective temperature (the temperature of a blackbodythat would emit the same amount of radiation) would be about 18 C. The surface temperature of this hypothetical planet is 33 C below Earth'sactual surface temperature of approximately 14 C. The mechanism that produces this difference between the actual surface temperature and theeffective temperature is due to the atmosphere and is known as the greenhouse effect. Earths natural greenhouse effect makes life as we know it possible. However, human activities, primarily the burning of fossil fuels and clearing offorests, have intensified the natural greenhouse effect, causing global warming. 14. Global warming is the observed century-scale rise in the average temperature of Earth's climate system. Since 1971, 90% of the increased energy has been stored in the oceans, mostly in the 0 to 700mregion. Despite the oceans' dominant role in energy storage, the term "global warming" is also used torefer to increases in average temperature of the air and sea at Earth's surface. Since the early 20thcentury, the global air and sea surface temperature has increased about 0.8 C (1.4 F), with about two-thirdsof the increase occurring since 1980. Each of the last three decades has been successively warmerat the Earth's surface than any preceding decade since 1850. Scientific understanding of the cause of global warming has been increasing. In itsfourth assessment (AR4 2007) of the relevant scientific literature, theIntergovernmental Panel on Climate Change (IPCC) reported that scientists were more than 90% certainthat most of global warming was being caused by increasing concentrations of greenhouse gasesproduced by human activities. In 2010 that finding was recognized by the national science academies ofall major industrialized nations. 15. Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels ofhydrogen ions (low pH). It can have harmful effects on plants, aquatic animals and infrastructure. Acid rain is caused byemissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids.Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positiveresults. Nitrogen oxides can also be produced naturally by lightning strikes and sulfur dioxide is produced by volcaniceruptions. The chemicals in acid rain can cause paint to peel, corrosion of steel structures such as bridges, and erosion ofstone statues. "Acid rain" is a popular term referring to the deposition of wet (rain, snow, sleet, fog, cloudwater, and dew) and dry(acidifying particles and gases) acidic components. Distilled water, once carbon dioxide is removed, has a neutral pH of 7.Liquids with a pH less than 7 are acidic, and those with a pH greater than 7 are alkaline. "Clean" or unpolluted rain has anacidic pH, but usually no lower than 5.7, because carbon dioxide and water in the air react together to form carbonic acid, aweak acid according to the following reaction: 16. Ride your bikeTell your friends and family about pollutionMake sure your parents get pollution checks ontheir carsRide the school bus 17. Learn more; stay up to dateJoin a group to stop pollutionEncourage your parents to carpool toworkSwitch off lights, fan, heat, etc. when youleave the room 18.</p>