seasons

Air Pollution

Review Name the bottom two layers of the atmosphere –Troposphere, stratosphere 75-80% of atmosphere’s mass is in the __ –Troposphere Distinguish between good and bad ozone –good: stratosphere, UV; bad: troposphere, lungs

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 97annual.html

Salt Lake City on a smoggy day

Killer London smog, 1952 December Very cold for several days People burned more coal Sulfur dioxide, particulates

Deaths during ’52 killer smog

London smogs Picadilly circus, London, winter, 1955 NOON

1948: Air pollution inversion (cool air trapped by warm air above it keeps pollution from dispersing) in Donora, Pennsylvania, kills 20 people and makes 40 percent of the town's 14,000 inhabitants ill. 1952: Sulfur-laden smog covers London and is responsible for 4,000 deaths over a two-week period. 1967: Air Quality Control Act passed by Congress, setting timetables for states to establish their own air quality standards. 1970: Congress passes the Clean Air Act, allowing the newly created Environmental Protection Agency to set national air quality standards. Also allowed states to establish their own stricter standards, which California did.

Clean Air Act 1970 Amendments to an earlier act ``To put the 1970 amendments in proper context, one needs to look back at Congress' prior efforts to control air pollution, particularly the Air Quality Act of That statute authorized the Secretary of Health, Education, and Welfare (who then had chief responsibility for federal environmental protection programs) to designate so-called air quality regions throughout the country; the states were given primary responsibility for adopting and enforcing pollution control standards within those regions. Some of us involved in the enactment of the 1967 statute had significant doubts as to the viability of the regional approach to air pollution control; after all, air contamination does not stop at neatly defined regional boundaries. Nevertheless, Congress as a whole and American industry were not yet convinced of the need for a national strategy for pollution control; therefore, as a first step, the 1967 statute's regional approach became the law of the land.’’ Paul Rogers, chair of House subcommittee on Health and the environment

Debate on Clean Air Act, 1970 During House floor debate: –A representative quote a mayor: ``If you want this town to grow, it has got to stink.’’ –A common view then –Similar arguments continue to be made with respect to efforts to control global warming

Clean Air Act Requires EPA to set National Ambient Air Quality Standards (NAAQS) for six ``criteria’’ air pollutants Ozone Sulfur dioxide Lead Carbon monoxide Nitrogen dioxide Particulate matter

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 –

Kinds of sources Stationary sources: have a fixed location –Point: source can be named individually –Nonpoint: diffuse sources, such as agriculture Mobile sources: Do not have a fixed location –Onroad: highway vehicles –Nonroad: not for highway use, including construction equipment, boats, planes Also, small diesel engines, such as lawn mowers

Emissions of hydrocarbons: molecules of carbon and hydrogen resulting from (i) incomplete fuel combustion and (ii) fuel evaporation

–Mt. Saint Helens – 100 tons SO 2 /day –Etna – 10,000 tons/day

Mediaseed - The Effects of Particle Pollution Go to lungusa.org for 4/29 Mediaseed - The Effects of ozoneMediaseed - The Effects of ozone

Is air quality getting better or worse in the U.S.?

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

Natural air pollution Who said the following: "I have flown twice over Mount St. Helens out on our west coast. I'm not a scientist and I don't know the figures, but I have a suspicion that that one little mountain has probably released more sulfur dioxide into the atmosphere of the world than has been released in the last ten years of automobile driving or things of that kind that people are so concerned about.’’ "Trees cause more pollution than automobiles do." –RONALD REAGAN

Natural sources The facts: –Volcanoes DO emit SO 2. Kilauea much worse than Mount St Helens. MSH probably emits less than cars; Kilauea more (largest SO 2 point-source emitter in the US). Volcanoes also put out particles and can cause health and climate effects –Some air pollution does come from trees, decay. Typically, spread out and not a health risk, unlike anthropogenic sources Wind, dustparticulates VolcanoesParticulates, SO2, CO2 Forest firesCO2, unburned HC VegetationVOCs, pollen Oceansalt

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 air/products.html

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

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: ppm

Mobile Source Emissions: Nitrogen Oxides

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

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

Mobile Source Emissions: Hydrocarbons – Precursors to Ozone

Carbon Monoxide (CO) Properties: colorless, odorless, heavier than air, % 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 % from auto exhaust Class: carbon oxides (CO 2, CO) EPA Standard: 9 ppm 5.5 billion tons enter atmosphere/year

Mobile Source Emissions - CO

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

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)

Mobile Source Emissions: Fine Particulate Matter (PM 2.5 )

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

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

Temperature inversion Makes effects of air pollutants worse Usually: sun warms air at Earth’s surface, which rises and mixes, dispersing pollutants Sometimes: layer of warm air above cooler, denser air, which does not rise and mix

Ordinarily, warm air rises, carrying pollutants with it If colder air is under warmer air, the air is stable, and pollution can be trapped

Another kind of temperature inversion Air warms up by compression as it flows downslope. Forms a ``lid’’ over colder air. This type of inversion common in Denver, which is to right of the mountains

Acid rain Sulfur dioxide and nitrogen oxides react in atmosphere  acidic chemicals that can travel long distances and return to earth Tall stacks reduce local pollution, but increase regional

Sudbury, Ont. superstack

SEE TEXTBOOK, P. 445Note: coal-burning plants in AZ, plume to NE

Acid rain impacts Erode metal and stone Acidifies lakes, leading to fish deaths Acidifies soil, leaching plant nutrients

The future of acid rain For better –Clean Air Act amendments of 1990 led to reductions in SO2 and Nox –Cap-and-trade program For worse –U.S. and China have huge coal reserves

Smog Photochemical smog –Air pollutants (VOCs, NOx) react under influence of sunlight and heat –Form: ground level ozone and other chemicals that together = smog Industrial smog –A mixture of sulfur dioxide, sulfuric acid and particulates –Often in winter, with coal burning (eg: London)

Industrial smog in China Bejing China is home to 20 of the world’s top 30 most smog-plagued cities

Factors influencing smog formation DECREASE Local climate: rain and snow wash pollutants out; dry areas more prone Winds: mix pollutants or blow them away Salt spray from ocean: can remove particulates INCREASE Tall buildings reduce wind Hills and mountains High temperatures

Indoor air pollution Often: a GREATER threat to health than outdoor air pollution EPA studies: –11 common pollutants often 2-5x higher indoors –May be higher in cars in urban areas –People spend more time indoors

Indoor air pollution Biggest problems –Formaldehyde: low levels emitted from many household products Furniture, paneling and plywood, insulation –Radon: natural radioactive gas found in soil Outdoors, disperses; indoors, may concentrate and contribute to lung cancer –Lead, asbestos, carbon monoxide, chloroform