Download presentation
Presentation is loading. Please wait.
Published byAnis Benson Modified over 8 years ago
1
Human Impact on the Atmosphere Human Impact on the Atmosphere Chapters 18 and 19 Living in the Environment, 11 th Edition, Miller Advanced Placement Environmental Science La Canada High School Dr. E
2
Pollution Thorpe, Gary S., M.S., (2002). Barron’s How to prepare for the AP Environmental Science Advanced Placement Exam The term “Smog” (smoke and fog) was first used in 1905 to describe sulfur dioxide emissionThe term “Smog” (smoke and fog) was first used in 1905 to describe sulfur dioxide emission In 1952, severe pollution took the lives of 5000 people in LondonIn 1952, severe pollution took the lives of 5000 people in London “It isn’t pollution that’s harming the environment. It’s the impurities in our air and water that are doing it.” Former U.S. Vice President Dan Quayle“It isn’t pollution that’s harming the environment. It’s the impurities in our air and water that are doing it.” Former U.S. Vice President Dan Quayle www.aqmd.gov/pubinfo/ 97annual.html
3
The Clean Air Act Congress found: Most people now live in urban areas Growth results in air pollution Air pollution endangers living things It decided: Prevention and control at the source was appropriate Such efforts are the responsibility of states and local authorities Federal funds and leadership are essential for the development of effective programs
4
Clean Air Act Originally signed 1963 –States controlled standards 1970 – Uniform Standards by Federal Govt. –Criteria Pollutants Primary – Human health risk Secondary – Protect materials, crops, climate, visibility, personal comfort
5
Clean Air Act 1990 version –Acid rain, urban smog, toxic air pollutants, ozone depletion, marketing pollution rights, VOC’s 1997 version –Reduced ambient ozone levels –Cost $15 billion/year -> save 15,000 lives –Reduce bronchitis cases by 60,000 per year –Reduce hospital respiratory admission 9000/year
6
Clean Air Act President George W. Bush signed rules amending Clean Air Act that allowed power plants and other industries to increase pollution significantly without adopting control measures
7
WASHINGTON (AP) -- A federal appeals court on Wednesday blocked new Bush administration changes to the Clean Air Act from going into effect the next day, in a challenge from state attorneys general and cities that argued they would harm the environment and public health. Appeals court blocks Bush clean air changes Wednesday, December 24, 2003 Posted: 2:10 PM EST (1910 GMT) http://www.cnn.com/2003/LAW/12/24/bush.clean.air.ap/index.html
8
Clean Air Act http://www.epa.gov/air/oaq_caa.html http://www.epa.gov/air/oaq_caa.html Title I - Air Pollution Prevention and Control –Part A - Air Quality and Emission Limitations –Part B - Ozone Protection (replaced by Title VI) –Part C - Prevention of Significant Deterioration of Air Quality –Part D - Plan Requirements for Nonattainment Areas Title II - Emission Standards for Moving Sources –Part A - Motor Vehicle Emission and Fuel Standards –Part B - Aircraft Emission Standards –Part C - Clean Fuel Vehicles Title III - General Title IV - Acid Deposition Control Title V - Permits Title VI - Stratospheric Ozone Protection
9
Outdoor Air Pollution
10
Primary Pollutants Secondary Pollutants Sources Natural Stationary CO CO 2 SO 2 NO NO 2 Most hydrocarbons Most suspended particles SO 3 HNO 3 H 2 SO 4 H2O2H2O2H2O2H2O2 O3O3O3O3PANs Most andsalts NO 3 – Mobile SO 4 2 –
11
Major Sources of Primary Pollutants Stationary Sources Combustion of fuels for power and heat – Power Plants Other burning such as Wood & crop burning or forest fires Industrial/ commercial processes Solvents and aerosols Mobile Sources Highway: cars, trucks, buses and motorcycles Off-highway: aircraft, boats, locomotives, farm equipment, RVs, construction machinery, and lawn mowers
13
54 million metric tons from mobile sources in 1990
14
Human Impact on Atmosphere Burning Fossil Fuels Using Nitrogen fertilizers and burning fossil fuels Refining petroleum and burning fossil fuels Manufacturing Adds CO 2 and O 3 to troposphere Global Warming Altering Climates Produces Acid Rain Releases NO, NO 2, N 2 O, and NH 3 into troposphere Produces acid rain Releases SO 2 into troposphere Releases toxic heavy metals (Pb, Cd, and As) into troposphere www.dr4.cnrs.fr/gif-2000/ air/products.html
15
Criteria Air Pollutants EPA uses six "criteria pollutants" as indicators of air quality 1. Nitrogen Dioxide: NO 2 2. Ozone: ground level O 3 3. Carbon monoxide: CO 4. Lead: Pb 5. Particulate Matter: PM 10 (PM 2.5) 6. Sulfur Dioxide: SO 2 Volatile Organic Compounds: (VOCs) EPA established for each concentrations above which adverse effects on health may occur
16
Nitrogen Dioxide (NO 2 ) Properties: reddish brown gas, formed as fuel burnt in car, strong oxidizing agent, forms Nitric acid in air Effects: acid rain, lung and heart problems, decreased visibility (yellow haze), suppresses plant growth Sources: fossil fuels combustion, power plants, forest fires, volcanoes, bacteria in soil Class: Nitrogen oxides (NO x ) EPA Standard: 0.053 ppm
17
Mobile Source Emissions: Nitrogen Oxides
18
Ozone (O 3 ) Properties: colorless, unpleasant odor, major part of photochemical smog Effects: lung irritant, damages plants, rubber, fabric, eyes, 0.1 ppm can lower PSN by 50%, Sources: Created by sunlight acting on NO x and VOC, photocopiers, cars, industry, gas vapors, chemical solvents, incomplete fuel combustion products Class: photochemical oxidants
19
Ozone (O 3 ) 10,000 to 15,000 people in US admitted to hospitals each year due to ozone- related illness Children more susceptible –Airways narrower –More time spent outdoors
20
Mobile Source Emissions: Hydrocarbons – Precursors to Ozone
21
Carbon Monoxide (CO) Properties: colorless, odorless, heavier than air, 0.0036% of atmosphere Effects: binds tighter to Hb than O 2, mental functions and visual acuity, even at low levels Sources: incomplete combustion of fossil fuels 60 - 95% from auto exhaust Class: carbon oxides (CO 2, CO) EPA Standard: 9 ppm 5.5 billion tons enter atmosphere/year
22
Mobile Source Emissions - CO
23
Lead (Pb) Properties: grayish metal Effects: accumulates in tissue; affects kidneys, liver and nervous system (children most susceptible); mental retardation; possible carcinogen; 20% of inner city kids have [high] Sources: particulates, smelters, batteries Class: toxic or heavy metals EPA Standard: 1.5 ug/m 3 2 million tons enter atmosphere/year
24
Suspended Particulate Matter (PM 10 ) Properties: particles suspended in air (<10 um) Effects: lung damage, mutagenic, carcinogenic, teratogenic Sources: burning coal or diesel, volcanoes, factories, unpaved roads, plowing, lint, pollen, spores, burning fields Class: SPM: dust, soot, asbestos, lead, PCBs, dioxins, pesticides EPA Standard: 50 ug/m 3 (annual mean)
25
Mobile Source Emissions: Fine Particulate Matter (PM 2.5 )
26
Sulfur Dioxide (SO 2 ) Properties: colorless gas with irritating odor Effects: produces acid rain (H 2 SO 4 ), breathing difficulties, eutrophication due to sulfate formation, lichen and moss are indicators Sources: burning high sulfur coal or oil, smelting or metals, paper manufacture Class: sulfur oxides EPA Standard: 0.3 ppm (annual mean) Combines with water and NH 4 to increase soil fertility
27
VOCs (Volatile Organic Compounds) Properties: organic compounds (hydrocarbons) that evaporate easily, usually aromatic Effects: eye and respiratory irritants; carcinogenic; liver, CNS, or kidney damage; damages plants; lowered visibility due to brown haze; global warming Sources: vehicles (largest source), evaporation of solvents or fossil fuels, aerosols, paint thinners, dry cleaning Class: HAPs (Hazardous Air Pollutants) –Methane –Benzene –Chlorofluorocarbons (CFCs), etc. Concentrations indoors up to 1000x outdoors 600 million tons of CFCs
28
Other Air Pollutants Carbon dioxideCarbon dioxide ChloroFluoroCarbonsChloroFluoroCarbons FormaldehydeFormaldehyde BenzeneBenzene AsbestosAsbestos ManganeseManganese DioxinsDioxins CadmiumCadmium Others not yet fully characterizedOthers not yet fully characterized
29
Formation & Intensity Factors Local climate (inversions, air pressure, temperature, humidity)Local climate (inversions, air pressure, temperature, humidity) Topography (hills and mountains)Topography (hills and mountains) Population densityPopulation density Amount of industryAmount of industry Fuels used by population and industry for heating, manufacturing, transportation, powerFuels used by population and industry for heating, manufacturing, transportation, power Weather: rain, snow,windWeather: rain, snow,wind Buildings (slow wind speed)Buildings (slow wind speed) Mass transit usedMass transit used EconomicsEconomics
30
Pollutants warm air cool air surface heated by sun warm air rises (incl. pollutants) cools off, mixes with air of equal density & disperses cool air warm air (inversion layer) surface cools rapidly (night) a layer of warm air overlays surface polluted surface air rises but cannot disperse remains trapped Thermal Inversion
31
...when polluted air is stagnant (weather conditions, geographic location) Los Angeles, CA Smog Forms
32
Primary Pollutants Secondary Pollutants Sources Natural Stationary CO CO 2 SO 2 NO NO 2 Most hydrocarbons Most suspended particles SO 3 HNO 3 H 2 SO 4 H2O2H2O2H2O2H2O2 O3O3O3O3PANs Most andsalts NO 3 – Mobile SO 4 2–
33
Photochemical Smog Primary Pollutants NO 2 + Hydrocarbons Auto Emissions UV radiation H 2 O + O 2 Secondary Pollutants HNO 3 O 3 nitric acidozone Photochemical Smog
34
Solar radiation Ultraviolet radiation NO Nitric oxide P h o t o c h e m i c a l S m o g H 2 O Water NO 2 Nitrogen dioxide Hydrocarbons O 2 Molecular oxygen HNO 3 Nitric acid PANs Peroxyacyl nitrates Aldehydes (e.g., formaldehyde) O 3 Ozone O Atomic oxygen Photochemical Smog
35
Indoor Air Pollution
36
Why is indoor air quality important? 70 to 90% of time spent indoors, mostly at home Many significant pollution sources in the home (e.g. gas cookers, paints and glues) Personal exposure to many common pollutants is driven by indoor exposure Especially important for susceptible groups – e.g. the sick, old and very young
37
Exposure Time spent in various environments in US and less-developed countries
38
House of Commons Select Committee Enquiry on Indoor Air Pollution (1991) “[There is] evidence that 3 million people have asthma in the UK… and this is increasing by 5% per annum.” “Overall there appears to be a worryingly large number of health problems which could be connected with indoor pollution and which affect very large numbers of the population.” [The Committee recommends that the Government] “develop guidelines and codes of practice for indoor air quality in buildings which specifically identify exposure limits for an extended list of pollutants…”
39
Sources of Indoor Air Pollutants Building materials Furniture Furnishings and fabrics Glues Cleaning products Other consumer products Combustion appliances (cookers and heaters) Open fires Tobacco smoking Cooking House dust mites, bacteria and moulds Outdoor air
40
Important Indoor Air pollutants Nitrogen dioxide Carbon monoxide Formaldehyde Volatile Organic Compounds (VOCs) House dust mites (and other allergens, e.g. from pets) Environmental tobacco smoke Fine particles Chlorinated organic compounds (e.g. pesticides) Asbestos and man-made mineral fibres Radon
41
Health Effects Nitrogen dioxide Respiratory irritant Elevated risk of respiratory illness in children, perhaps resulting from increased susceptibility to respiratory infection; inconsistent evidence for effects in adults Concentrations in kitchens can readily exceed WHO and EPA standards
42
Health Effects Carbon monoxide An asphyxiant and toxicant Hazard of acute intoxication, mostly from malfunctioning fuel-burning appliances and inadequate or blocked flues Possibility of chronic effects of long-term exposure to non- lethal concentrations, particularly amongst susceptible groups
43
Health Effects Formaldehyde Sensory and respiratory irritant and sensitizer Possible increased risk of asthma and chronic bronchitis in children at higher exposure levels Individual differences in sensory and other transient responses Caution over rising indoor concentrations
44
Health Effects Volatile Organic Compounds (VOCs) Occur in complex and variable mixtures Main health effects relate to comfort and well- being, but benzene (and other VOCs) are carcinogenic Concern about possible role of VOCs in the aetiology of multiple chemical sensitivity; also implicated in sick building syndrome
45
Health Effects House dust mites House dust mites produce Der p1 allergen, a potent sensitizer Good evidence of increased risk of sensitization with increasing allergen exposure, but this does not necessarily lead to asthma Small reductions in exposure will not necessarily lead to reduced incidence and/or symptoms Indoor humidity is important
46
Health Effects Fungi and bacteria Dampness and mould-growth linked to self- reported respiratory conditions, but little convincing evidence for association between measured airborne fungi and respiratory disease Insufficient data to relate exposure to (non- pathogenic) bacteria to health effects in the indoor environment
47
Health Effects Environmental tobacco smoke (ETS) Sudden infant death syndrome Lower respiratory tract illness Middle ear disease Asthma 12 million children exposed to secondhand smoke in homes
48
Health Effects Fine particles Consistent evidence that exposure to small airborne particles (e.g. PM10) in ambient air can impact on human health; mechanisms uncertain Chronic Obstructive Pulmonary Disease and Cardiovascular Disease patients and asthmatics probably at extra risk Relative importance of indoor sources is unknown
49
Health Effects Radon Can cause lung cancer Estimated that 7,000 to 30,000 Americans die each year from radon-induced lung cancer Only smoking causes more lung cancer deaths Smokers more at risk than non-smokers
50
Radon Risk: Non-Smoker Radon Level (pCI/L) If 1000 people who did not smoke were exposed to this level over a lifetime.. About X would get lung cancer This risk of cancer from radon exposure compares to … What to do: 208Being killed in a violent crime Fix your home 104Fix your home 8310x risk of dying in a plane crash Fix your home 42Risk of drowningFix your home 2<1Risk of dying in a home fire Fix your home 1.3<1Average indoor radon levelFix your home 0.4<1Average indoor radon levelFix your home If you are a former smoker, your risk may be higher
51
Radon Risk: Smoker Radon Level (pCI/L) If 1000 people who smoke were exposed to this level over a lifetime.. About X would get lung cancer This risk of cancer from radon exposure compares to … What to do: Stop smoking and … 20135100x risk of drowningFix your home 1071100x risk of dying in a home fire Fix your home 857Fix your home 429100x risk of dying in a plane crash Fix your home 2152x the risk of dying in a car crash Fix your home 1.39Average indoor radon levelFix your home 0.43Average indoor radon levelFix your home If you are a former smoker, your risk may be lower
52
Radon 55% of our exposure to radiation comes from radon colorless, tasteless, odorless gas formed from the decay of uranium found in nearly all soils levels vary
53
(From: http://www.epa.gov/iaq/radon/zonemap.html) Zone pCi/L 1 >4 2 2 - 4 3 <2
54
Radon: How it Enters Buildings Cracks in solid floors Construction joints Cracks in walls Gaps in suspended floors Gaps around service pipes Cavities inside walls The water supply http://www.epa.gov/iaq/radon/pubs/citguide.html#howdoes
55
Radon: Reducing the Risks Sealing cracks in floors and walls Simple systems using pipes and fans More information: http://www.epa.gov/iaq/radon/pubs/consguid.html#reductiont ech
56
Sick Building Syndrome (SBS) vs Building Related Illness (BRI)
57
Sick Building Syndrome A persistent set of symptoms in > 20% population Causes(s) not known or recognizable Complaints/Symptoms relieved after exiting building
58
Complaints/Symptoms Headaches Fatigue Reduced Mentation Irritability Eye, nose or throat irritation Dry Skin Nasal Congestion Difficulty Breathing Nose Bleeds Nausea
59
Building Related Illness Clinically Recognized Disease Exposure to indoor air pollutants Recognizable Causes
60
Clinically Recognized Diseases –Pontiac Fever – Legionella spp. –Legionnaire's Disease –Hypersensitivity Pneumonitis –Humidifier Fever –Asthma –Allergy –Respiratory Disease Chronic Obstructive Pulmonary Disease
61
Ventilation
62
Movement of Air Into / Out of Homes Amount of air available to dilute pollutants –important indicator of the likely contaminant concentration Indoor air can mix with outside air by three mechanisms –infiltration –natural ventilation –forced ventilation
63
Movement of Air Into / Out of Homes Infiltration –natural air exchange that occurs between a building and its environment when the doors and windows are closed –leakage through holes or openings in the building envelope –pressure induced due to pressure differentials inside and outside of the building especially important with cracks and other openings in wall
64
Movement of Air Into / Out of Homes Infiltration –Temperature induced (stack effect) driven by air movement through holes in floors, ceilings in winter, warm air in a building wants to rise, exits through cracks in ceiling and draws in
65
Movement of Air Into / Out of Homes Natural ventilation –air exchange that occurs when windows or doors are opened to increase air circulation Forced ventilation –mechanical air handling systems used to induce air exchange using fans and blowers Trade-offs –cut infiltration to decrease heating and cooling costs vs. indoor air quality problems
66
Movement of Air Into / Out of Homes Infiltration rates –Influenced by how fast wind is blowing, pressure differentials temperature differential between inside and outside of house location of leaks in building envelope
67
Air Pollution Prevention
68
Specific Air Pollution Treatment Technology Traditional –Move factory to remote location –Build taller smokestack so wind blows pollution elsewhere New –Biofiltration : vapors pumped through soil where microbes degrade –High-energy destruction: high-voltage electricity –Membrane separation: diffusion of organic vapors through membrane –Oxidation: High temperature combustor
69
Absorption
70
Adsorption
71
Combustion
72
Cyclone
73
Filtration
74
Electrostatic Precipitator
75
Liquid Scrubber
76
Sulfur Dioxide Control http://www.apt.lanl.gov/projects/cctc/factsheets/puair/adflugasdemo.html
77
Air Pollution Results
79
Comparison of 1970 and 1999 Emissions
83
Number of People Living in Counties with Air Quality Concentrations Above the Level of the National Ambient Air Quality Standards (NAAQS) in 1999
84
Trends in Sulfur Dioxide Emissions Following Implementation of Phase I of the Acid Rain Program: Total State-level Utility SO2 (1980, 1990, 1999)
85
Fifty Years of Air Pollution Figures are in millions of metric tons per year
86
Mobile Sources: The Last Ten Years -10% -29% -8% -85% -3% -24% VOCs CO NO x PM 10 SO x Lead Percent reductions shown are based on estimates of tons/year from mobile sources over the 1981 - 1990 time period
87
Who is Affected by Air Pollution? 63 22 9 19 1 5 Ozone CO NO 2 PM 10 SO 2 Lead Millions of people living in counties with air quality that exceeds each NAAQS (1990 data) Over 74 million people are subjected to high levels of at least one of these pollutants
88
Milestones in the Control of Automotive Emissions 1952 - Autos linked to air pollution 1963 - Original CAA, PCV valves 1968 - HC & CO exhaust controls 1970 - CAA amendments, EPA formed 1971 - Evaporative controls 1972 - First I/M Program 1973 - NOx exhaust controls 1975 - First catalytic converters 1981 - New cars meet statutory limits 1989 - Volatility limits on gasoline 1990 - New CAA Amendments
89
1987 Montreal Protocol: CFC emissions should be reduced by 50% by the year 2000 (they had been increasing 3% per year.) 1990 London amendments: production of CFCs, CCl4, and halons should cease entirely by 2000. 1992 Copenhagen agreements: phase- out accelerated to 1996.
90
Goals of Kyoto Protocol Reduction of greenhouse gases to below 1990 levels: 5.2% world wide reduction on average by 2008- 2012 6% for Canada by 2008-2012 When sufficient countries ratify the Protocol (at least 55 countries comprising at least 55% of emissions), Protocol comes into effect USA - 25% of emissions
91
Kyoto Emissions Agreement
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.