14 Atmospheric Science and Air Pollution © 2010 Pearson Education Canada PowerPoint ® Slides prepared by Stephen Turnbull Copyright © 2013 Pearson Canada.

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Housekeeping Items There is a film showing on campus next week that would definitely be worth catching called “Green Fire.” Malala, the 14-year old Pakistani advocate for girls’ education, continues to recover in a London hospital from the attempted assassination by Taliban gunmen. Maggie drew my attention to a speech given twenty years ago by Severn Suzuki, David’s daughter, at a UN global forum in Rio on sustainable development. It’s only 5 minutes long and it’s worth watching. She was only 13 at the time: http://www.youtube.com/watch?v=TQmz6Rbpnu0&feature=fvwrel http://www.youtube.com/watch?v=TQmz6Rbpnu0&feature=fvwrel Today we will focus on Chapter 14.

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Upon successfully completing this chapter, you will be able to Describe the composition, structure, and function of Earth’s atmosphere Outline the scope of outdoor air pollution and assess potential solutions Explain stratospheric ozone depletion and identify steps taken to address it Define acidic deposition and illustrate its consequences Characterize the scope of indoor air pollution and assess potential solutions 14-3

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Central Case: The Rain and the big Nickel Mining and refining in Sudbury, Ontario generates high SO 2 emissions, leading to acid rain 1972: Built a 380m superstack to disperse emissions 1980s: cleaned emissions prior to releasing them Acidification and remediation studied at the Experimental Lakes Area in northwestern Ontario (program recently abolished by Harper) Better ecological awareness today “Despite Canada’s success at reducing acid-causing emissions, acid deposition is still affecting our environment.” – Environment Canada 14-4

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. The atmosphere and weather Atmosphere = the thin layer of gases that surrounds Earth -Absorbs radiation and moderates climate -Transports and recycles water and nutrients -78% nitrogen gas, 21% oxygen gas, 1% other gases -Its four layers differ in temperature, density and composition Minute concentrations of permanent (remain at stable concentrations) and variable gases (varying concentrations) Human activity is changing the amounts of some gases 14-6

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. The atmosphere is layered Troposphere = bottommost layer -Air for breathing, weather -Temperature declines with altitude -Tropopause = limits mixing between troposphere and the layer above it Stratosphere = 11-50 km (7-31 mi) above sea level -Drier and less dense, with little vertical mixing -Colder in its lower regions -Contains UV radiation-blocking ozone, 17-30 km (10-19 mi) above sea level 14-8

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. The atmosphere is layered (cont’d) Mesosphere = 50-80 km (31-56 mi) above sea level -Extremely low air pressure -Temperatures decrease with altitude Thermosphere = atmosphere’s top layer -Extends upward to 500 m (300 mi) 14-10

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Atmospheric properties include temperature, pressure, and humidity Atmospheric pressure = measures the force per unit area produced by a column of air Relative humidity = the ratio of water vapor a given volume of air contains to the amount it could contain at a given temperature Microclimate = different weather pattern on side of hill sheltered from wind or direct sunlight (or, on a larger scale, the “rain shadow” effect) 14-11

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Solar energy heats the atmosphere, helps create seasons, and causes air to circulate The spatial relationship between the Earth and sun determines the amount of solar energy striking the Earth Energy from the sun -Heats air -Moves air -Creates seasons -Influences weather and climate Solar radiation is highest near the equator 14-12

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Solar energy heats the atmosphere, helps create seasons, and causes air to circulate (cont’d) Earth is titled on its axis by about 23.5% Northern and Southern Hemispheres each tilt toward the sun for half the year -Results in change of seasons -Regions near equator largely unaffected -Near poles the effect is strong 14-14

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Solar energy heats the atmosphere, helps create seasons, and causes air to circulate (cont’d) Convective circulation = less dense, warmer air rises and creates vertical currents -Rising air expands and cools -Cool air descends and becomes denser, replacing warm air -Influences both weather and climate 14-16

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. The atmosphere drives weather and climate Weather = specifies atmospheric conditions over short time periods and within a small geographic areas Climate = describes patterns of atmospheric conditions across large geographic regions over long periods of time “Climate is what we expect; weather is what we get.” - Mark Twain 14-18

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Air masses interact to produce weather Front = the boundary between air masses that differ in temperature, moisture, and density 14-19 Warm Front = the boundary where warm moist air replaces colder, drier air Cold Front = the boundary where colder, drier air displaces warmer, moister air

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Air masses interact to produce weather (cont’d) High-pressure system = air that moves away from a center of high pressure as it descends -Brings fair weather Low-pressure system = air moves toward the low atmospheric pressure at the center of the system and spirals upward -Clouds and precipitation 14-20

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Air masses interact to produce weather (cont’d) Normally there is vertical mixing Thermal inversion = a layer of cool air occurs beneath a layer of warmer air -Inversion layer = the band of air in which temperature rises with altitude -Denser, cooler air at the bottom of the layer resists mixing 14-21

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Large-scale circulation systems produce global climate patterns Hadley cells = a pair of convective air currents near the equator where surface air warms, rises, and expands Ferrel cells and polar cells = convective cells that lift air and create precipitation at 60 degrees latitude north and south These interact with Earth’s rotation to produce global wind patterns Coriolis effect = the north-south air currents of the convective cells appear to be deflected from a straight path 14-22

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Large-scale circulation systems produce global climate patterns (cont’d) Doldrums = near the equator -Few winds Trade winds = between the equator and 30 degrees latitude -Blow from east to west Westerlies = from 30 to 60 degrees latitude -Originate from the west and blow east 14-24

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Outdoor air pollution Air pollutants = gases and particulate material added to the atmosphere -Can affect climate or harm people (example of Atlanta during the Olympics) Air pollution = the release of pollutants Outdoor (ambient) air pollution = pollution outside -Has recently decreased due to government policy and improved technologies in developed countries -Developing countries and urban areas still have significant problems and, in some cases, it’s growing worse 14-26

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Dust storms = Hundreds of millions of tons of dust are blown westward across the Atlantic Ocean by trade winds every year -From Africa to the Americas -Unsustainable farming and grazing, erosion and desertification make these worse (Grapes of Wrath chronicles the migration of the ‘Okies’ in the 1930s) Natural sources can pollute 14-27

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Natural sources can pollute (cont’d) Volcanic eruptions = release large quantities of particulate matter, sulfur dioxide & other gases (impact of volvanic eruptions in Iceland on air travel) Can remain for months or years Aerosols = reflect sunlight back into space and cool the atmosphere and surface -Sulphur dioxide 14-28

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Natural sources can pollute (cont’d) Burning vegetation = pollutes atmosphere with soot and gases Over 60 million hectares of forests and grasslands burn per year Fires are made more severe by human action -Decades of fire suppression -Fires from “slash-and- burn” clearing of forests 14-29

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. We create various types of outdoor air pollution Point Sources = specific spots where large quantities of pollutants are discharged (power plants and factories) Nonpoint Sources = more diffuse, consisting of many small sources (automobiles) Primary Pollutants = directly harmful and can react to form harmful substances (soot and carbon dioxide) Secondary Pollutants = form when primary pollutants interact or react with constituents or components of the atmosphere (tropospheric ozone and sulfuric acid) 14-30

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. CEPA identifies harmful airborne substances 1999: Canadian Environmental Protection Act Environment Canada groups pollutants of greatest concern into four categories: -Criteria air contaminants -Persistent organic pollutants -Heavy metals -Toxic air pollutants 14-31

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. CEPA identifies harmful airborne substances (cont’d) Criteria air contaminants = pollutants judged to pose especially great threats to human health, produced by a number of processes (burning of fossil fuels) Sulphur dioxide (SO 2 ) Nitrogen dioxide (NO 2 ) Particulate matter (PM) Volatile organic compounds (VOC or VOX) Carbon monoxide (CO) Ammonia (NH 3 ) Tropospheric (or ground-level) ozone (O 3 ) 14-32

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Bad Air Days Are you sensitive to smog? Do you suffer from itchy eyes, burning lungs, or other symptoms on “bad air days”? Do you think there is a smog problem in your area? If you visit the website of the National Air Pollution Surveillance Network (NAPS), maintained by Environment Canada, you can watch animations of severe smog events in which ground-level ozone exceeded the accepted air quality standard levels over very large areas of both Canada and the United States (www.etc-te.ec.gc.ca/NAPS/naps_smog_e.html).www.etc-te.ec.gc.ca/NAPS/naps_smog_e.html weighing the issues 14-33 Air quality in Nanaimo?

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. CEPA identifies harmful airborne substances (cont’d) Persistent organic pollutants = can last in the environment for long periods of time, they are volatile (evaporate readily) They can enter food supply Bioaccumulate in body tissues Significant impact on human health and environment Come primary from human activity Examples include industrial chemicals -PCBs -DDT -Contaminants from incomplete combustion processes 14-34

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. CEPA identifies harmful airborne substances (cont’d) Heavy metals = can be transported by air, water, and food supply, and can reside in the sediment for long periods of time Poisonous even in low concentrations Accumulate in body tissues Carried long distances from source Mercury and lead 14-35

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. CEPA identifies harmful airborne substances (cont’d) Toxic air pollutants = broad category of “other” pollutants as being harmful or toxic Cause cancer Cause developmental or neurological problems in various body systems. Overlaps with other types of air pollutants (lead, ozone), plus asbestos and CFCs Most are produced by human activities (smelting, sewage treatment, industrial processes) 14-36

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Investigating Your Region’s Air Quality How polluted is the air near where you live? Go to the National Pollutant Release Inventory (NPRI) website at www.ec.gc.ca/pdb/npri/npri_home_e.cfm. Use the Google Earth mapping tool to check on the amounts of pollutants released in your own province or local area. www.ec.gc.ca/pdb/npri/npri_home_e.cfm Are there any specific facilities in your area that are major emitters of atmospheric pollutants? Tip: look into Harmac weighing the issues 14-37

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Government agencies share in dealing with air pollution Federal -Managed through Environment Canada (primarily) -1999: Canadian Environmental Protection Act (CEPA) -Enters into international agreements (e.g. Montreal Protocol, Kyoto Protocol) -Canada was first developed country to withdraw from Kyoto in 2011 -Enters into transboundary agreements with the U.S. (e.g. Canada-United States Air Quality Agreement) 14-38

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Government agencies share in dealing with air pollution (cont’d) Provincial/territorial -Managed through each environment ministry -Canadian Council of Ministers of the Environment (CCME) -Harmonization Accord, Canada-Wide Standards Sub-Agreement, National Ambient Air Quality Objectives 14-39

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Government agencies share in dealing with air pollution (cont’d) Municipal -Only Montreal and Greater Vancouver regulate sources of air pollution -Most municipalities raise public awareness -Top concerns differ from one region to another -Mississauga, Ontario = air quality -Halifax, Nova Scotia = wastewater management 14-40

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Monitoring shows that many forms of air pollution have decreased Cleaner-burning vehicles and catalytic converters decrease carbon monoxide Permit-trading programs and clean coal technologies reduce SO 2 emissions Scrubbers = technologies that chemically convert or physically remove pollutants before they leave the smokestacks Phaseout of leaded gasoline Improved technologies and federal policies 14-41

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Smog is the most common, widespread air quality problem Smog = unhealthy mixtures of air pollutants over urban areas Industrial (gray air) smog = industries burn coal or oil -Occurs in cooler, hilly areas -Government regulations in developed countries reduced smog -Coal-burning industrializing countries face significant health risks 14-42

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Photochemical smog is produced by a complex series of reactions Light-driven reactions of primary pollutants and normal atmospheric compounds Morning traffic exhaust releases pollutants Irritates eyes, noses, and throats Vehicle inspection programs have decreased smog 14-44

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Air quality is a rural issue, too Airborne pesticides from farms Industrial pollutants drifting from cities, factories and powerplants Feedlots, where cattle, hogs, or chickens are raised in dense concentrations -Voluminous amounts of methane, hydrogen sulfide, and ammonia -People living or working nearby have high rates of respiratory problems 14-45

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Industrializing nations are suffering increasing air pollution Outdoor pollution is increasing China has the world’s worst air pollution -Four out of five Chinese cities had emissions above the threshold set by WHO Southern Asian brown cloud = a 3 km-thick layer of pollution that reduces sunlight by 10-15%, affects climate, decreases productivity, and kills thousands each year 14-46

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Synthetic chemicals deplete stratospheric ozone Ozone layer = ozone in the lower stratosphere -12 ppm concentrations effectively block incoming damaging ultraviolet radiation Chlorofluorocarbons (CFCs) = chemicals that attack ozone -1 million metric tons/year were produced in early 1970s -Releases chlorine atoms that split ozone 14-47

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Synthetic chemicals deplete stratospheric ozone (cont’d) Ozone hole = ozone levels over Antarctica had declined by 40-60% Global ozone depletion causes skin cancer, harms crops and decreases ocean productivity 14-48

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. There are still many questions to be resolved about ozone depletion Will ozone depletion spread from the polar regions to encompass mid-latitude regions? What is the actual relationship between ozone depletion and human health impacts? What are the other potential impacts of ozone depletion (e.g. on ecosystems)? Are the substitute chemicals that are being proposed in international agreements definitely less damaging to the stratospheric ozone layer? 14-49

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. The Montreal Protocol addressed ozone depletion 1987: Montreal Protocol = 197 nations agreed to cut CFC production in half -Follow-up agreements deepened cuts, advanced timetables and addresses other ozone-depleting chemicals -Today, production and use of ozone-depleting chemicals has decreased 95% -The ozone layer is beginning to recover Challenges still face us -CFCs will remain in the stratosphere for a long time -Nations can ask for exemptions to the ban -United States to use methyl bromide to control pests on strawberries 14-50

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. The Montreal Protocol addressed ozone depletion (cont’d) Considered the biggest environmental success story -Policymakers included industry in helping solve the problem -Adaptive management strategy allowed changes in response to new scientific data, technological advances, and economic figures The Montreal Protocol can serve as a model for international environmental cooperation 14-51

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Acid deposition is another transboundary pollution problem Acidic deposition = the deposition of acid, or acid- forming pollutants, from the atmosphere onto Earth’s surface -Acid rain = precipitation of acid -Atmospheric deposition = the wet or dry deposition on land of pollutants Originates from burning fossil fuels -release sulfur dioxide and nitrogen oxides -react with water to form sulfuric and nitric acids 14-52

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Acid deposition is another transboundary pollution problem (cont’d) Rain and other forms of precipitation with pH of less than 5.1 are considered acidified Acidic deposition can have wide-ranging, cumulative detrimental effects on ecosystems and on our built environment -Acids leach nutrients from the topsoil -Alters soil chemistry harming plants -Mobilizes toxic metal ions -Run-off into surface waters -Erodes and corrodes built structures 14-54

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Acid deposition has not been reduced as much as scientists had hoped New technologies such as scrubbers have helped SO 2 emissions are lower NO x emissions are higher Acid deposition’s effects are worse than predicted 14-55

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Indoor air pollution Indoor air contains higher concentrations of pollutants than outdoor air -6,000 people die per day from indoor air pollution The average person in North America is indoors at least 90% of the time -Exposed to synthetic materials (insecticides, cleaning fluids, plastics, and chemically treated wood) -1973-74: ventilation systems were sealed off and windows put in that did not open, trapping pollutants inside 14-57

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Indoor air pollution in the developing world arises from fuelwood burning Burning wood, charcoal, dung, crop wastes for cooking and eating Kills 1.6 million people each year Causes pneumonia, bronchitis, allergies, cataracts, asthma, heart disease, cancer and premature death 14-58

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Tobacco smoke and radon are the most dangerous indoor pollutants in the developed world Secondhand smoke from cigarettes is especially dangerous -Containing over 4000 dangerous chemicals -Causes eye, nose, and throat irritation -Smoking has declined in developed nations After cigarette smoke, radon gas is the second-leading cause of lung cancer in the developed world -Colourless, odourless gas that can seep into buildings 14-59

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Many VOCs pollute indoor air VOCs = volatile organic compounds Released by everything from plastics and oils to perfumes and paints Most VOCs are released in very small amounts Unclear health implications due to low concentrations Also include pesticides, which are found indoors more often than outdoors due to seepage Formaldehyde, which leaks from pressed wood and insulation, irritates mucous membranes and induces skin allergies 14-60

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Living organisms can pollute indoors Tiny living organisms can also pollute Includes dust mites and animal dander worsen asthma Fungi, mold, mildew, airborne bacteria cause severe allergies, asthma, and other respiratory ailments Sick building syndrome = a sickness produced by indoor pollution with general and nonspecific symptoms -Solved by using low-toxicity building materials and good ventilation 14-62

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. How Safe Is Your Indoor Environment? Think about the amount of time you spend indoors. Name the potential indoor air quality hazards in your home, work, or school environment. What could you do to make the indoor spaces you use safer? weighing the issues 14-63

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Living organisms can pollute indoor spaces Dust mites and animal dander Fungi, mould, and mildew Airborne bacteria (Legionnaire’s disease) Microbes that induce allergic responses are thought to be a major cause of sickness produced by indoor pollution -Sick-building syndrome 14-64

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. We can reduce indoor air pollution In developed countries: -Use low-toxicity material -Monitor air quality -Keep rooms clean -Limit exposure to chemicals In developing countries: -Dry wood before burning -Cook outside -Use less-polluting fuels (natural gas) 14-65

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. Conclusion Indoor air pollution is a potentially serious health threat Outdoor air pollution has been addressed by government legislation and regulation in developed countries Improvement is required in reducing acidic deposition, photochemical smog Avoiding unhealthy pollutants in developing world will pose a challenge as less-wealthy nations industrialize 14-66

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. QUESTION: Review Ozone in the _________ is a pollutant, but in the ______ is vital for life a)Stratosphere, troposphere b)Troposphere, stratosphere c)Troposphere, tropopause d)Stratosphere, thermosphere 14-68

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. QUESTION: Review _____ is defined as the ratio of water vapor in the atmosphere compared to the amount the atmosphere could contain a)Atmospheric pressure b)Ozonification c)Temperature d)Relative humidity 14-69

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. QUESTION: Review If you were on a sailing ship going from Europe to Canada, you would want to be in the ________ a)Doldrums b)Trade winds c)Westerlies d)Polar cell 14-70

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. QUESTION: Review Which criteria pollutant is colorless, odorless, and poses a risk to humans, even in small amounts? a)Sulfur dioxide b)Nitrogen dioxide c)Tropospheric ozone d)Carbon monoxide 14-71

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. QUESTION: Review The Montreal Protocol addressed _______ a)Global warming, and was not successful b)Criteria pollutants, and was successful c)Ozone depletion, and was successful d)Acid deposition, and was successful 14-72

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. QUESTION: Interpreting Graphs and Data What does this graph show about the mesosphere? a)It contains the most ozone b)It is a very thin layer c)Temperature decreases with increasing altitude d)Temperature increases with increasing altitude 14-73

© 2010 Pearson Education Canada Copyright © 2013 Pearson Canada Inc. QUESTION: Viewpoints Should the government be able to prevent restaurants from allowing smoking, to protect people from secondhand smoke? a)Yes; I don’t want to be exposed to this form of pollution b)Yes, only if the restaurant agrees c)No, let the restaurant owner decide d)No; I want to be able to smoke in a restaurant 14-74

14 Atmospheric Science and Air Pollution © 2010 Pearson Education Canada PowerPoint ® Slides prepared by Stephen Turnbull Copyright © 2013 Pearson Canada.

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14 Atmospheric Science and Air Pollution © 2010 Pearson Education Canada PowerPoint ® Slides prepared by Stephen Turnbull Copyright © 2013 Pearson Canada.

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