Chapter 18 Air Pollution18.1- Intro to Air Pollution- Atmosphere is a resource for chemical elements and a a medium for depositing wasteso Early photosynthetic plants dumped waste product in atmosphere Oxygen rich air!- Industrialization has rapidly increased air pollution18.2 Pollution of the Atmosphere- Pollutants that enter the atmosphere may be degraded by natural processes within the atmosphere as it may become pollutants in the hydrologic and geochemical cycleo Ex- Acid rain- Beginning with Industrial Revolution, air pollution became more noticeableo Smog= smoke and fog- Today- pollution is a serious health hazardo Ruins human artifactso Damages aesthetics18.3 Sources of Air Pollution- 2 sourceso stationary- fixed locations fugitive source- generate pollution from open areas exposed to wind point source- pollution from controllable site area source- location that emit air pollutants from several sources within a well defined areao mobile source- move from place to place with yielding emissions18.4 Air Pollutants- major pollutants occur in a gaseous form or as particlate matterAIR TOXINS- air pollutnats known to cause cancer or serious health problems- classified byo whether they cause cancero tendency to cause respiratory, reproductive, neurological or immune diseasePRIMARY AND SECONDARY POLLUTANTS- Primary- emitted directly into the airo Major ones are carbon monoxide, nitrogen oxide, sulfur oxide, particulates and volatile organic compounds- Secondary- produced when primary pollutants react with normal atmospheric compoundsSULFUR DIOXIDE- Colorless and odorless- Undergoes oxidation to form sulfuric acid- Caused by fossil fuel burning, primarily coalo And industrial processes- Destructive effects- paint and metal corrosion, plant injury, lung damageNITROGEN OXIDES- Most important form is nitrogen dioxide- One of the main contributors of smog- From cars and burning of fossil fuels- Causes- plant damage, nose, eyes and throat irritability, o BUT promotes plant growth when nitrate is deposited in soilCARBON MONOXIDE- Colorless and odorless- Extremely toxico Attaches to hemoglobin and prevents the proper absorption of oxygenOZONE AND OTHER PHOTOCHEMICAL OXIDANTS- Photochemical oxidants result from atmospheric interaction of sunlight with pollutants- Sweet odor- Damages rubber, paint textiles- Pollutant near earth- Ozone layer- protector of life in stratosphere- Can kill plants and cause respiratory issuesVOLATILE ORGANIC COMPOUNDS- Wide variety of compounds used as solvents in industrial processes like dry cleaning, adhesive products, art…HYDROGEN SULFIDE- Highly toxic gas- Corrosive- Rotten egg odor- Produced form natural sources like swamps, bogs…- Damages plants and healthHYDROGEN FLOURIDE- Gaseous pollutant released by industrial activity like burning coall- May cause problems fro plants and animalsOther Hazardous Gases- Chlorine gases- used in agricultural processes- Sewage treatment chemicals- Some chemicals are so toxic that extreme care is taken to make sure they do not enter the environmento Methyl isocynateParticulate Matter 10 and 2.5- Particles of a solid or liquid substance depending on size- Numbers refer to diameter- Desertification, volcanic eruption, fire, and farming add these - Exampleso Asbestos- o Lead-o Cadium-18.5 Urban Air Pollution- Most pollution concentrated in urban areas where there are lots of industryINFLUENCE OF METEOROLOGY AND TOPOGRAPHY- Meteorological conditions can determine whether air pollution is only a nuisance or a major health problem- Atmospheric inversion- when warm air overlies cool airo Prob where there is stagnated air masso Mountain can act as a barrier and cause this- Evaluating meteorological conditions can be extremely helpful when predicting areas that will have potential smog problemso Ex- cities situated in a topographic bowl will have issuesPOTENTIAL FOR URBAN AIR POLLUTION- Factors that affect extent of urban air pollutiono Rate of pollutant emissionso Distance that a mass of air moves through urban air pollution sources average speed of windo Height of mixing layerSMOG PRODUCTION- Two major types of smogo Sulfurous- London type, gray airo Photochemical- LA type, brown air complex involving nitrogen oxides, hydrocarbons, and solar radiation from car use big in S CaliforniaFUTURE OF AIR POLLUTION IN URBAN AREAS- generally, ari pollution of urban areas has decreasedo due to  cars and buildings burning less fuel more efficiently burn cleaner, improved fuel- **But still unhealthy18.6 Indoor Air Pollution- one of the most serious environmental hazards that people face in homes and workplaceso indoor air can be polluted with smoke, chimials, disease carrying organisms, and radono buildings are made of many substances that can release chemicals into the air18.7 Control of Air Pollution- the best strategy is to reduce emissions through conservation and efficiency measureso ***Burn less fossil fuelCONTROL OF PARTICULATES- Power plants use a variety of setting chambers or collectors to control the release of coarse particulates- From fugitive sources, they must be controlled at the site before the erode by the windo Protect open areas and control dustControl of Automobile Pollution- Best controlled by regulating automobile exhausto Recirculation exhaust gas within the automobile’s engine- We cano Develop and use fuel additives and reformulated fuel that produces a cleaner fuelo Require new cars to have improved fuel efficiency which would encourage or require use of electric cars or hybridsControl of Sulfur Dioxide- Reduced by abatement measures performed before, during, or after combustion- Change from high to low sulfur- But most coal burning is done in the east and low sulfur is in west- Abatement has been successful in Japan18.8 Air Quality Standards- Associated with emission standards that attempt to control air pollutiono Have countries set max of emissiono Diff from country to countryCLEAN AIR LEGISLATION IN THE US- Clean Air act-1970o Two levels of air quality standards Primary- protect human health but not damages of effects to structures of paint and plants Secondary- designed to prevent other environmental degradationo 1990 amendment tightened controlo more stringent control on sulfur dioxideo reduction in nitrogen oxide emissionsMONITORING AIR