The atmosphere is the key symbol of global interdependence.

1. The atmosphere is the key symbol of global interdependence. If we can’t solve some of our problems in the face of threats to this global commons, then I can’t be very optimistic about the future of the world. Margaret Mead

2. The Atmosphere (18) We live at the bottom of a thin envelope of gases surrounding the Earth, called the atmosphere. It is divided into several layers based on drastic changes in temperature caused by differences in the absorption of incoming solar energy. Two other factors that vary throughout the atmosphere are density and atmospheric pressure. Both properties are influenced by gravity, which pulls gas molecules in the atmosphere towards the Earth’s surface. Density is the mass per volume of a substance. The density of air varies with elevation. The air at sea level is far more dense than the air in the high mountains. Atmospheric pressure decreases with altitude because there are fewer gas molecules at higher altitudes. Atmospheric pressure is the force, or mass, per unit area of a column of air. (the weight of the air on your body). At sea level it is equal to 14.69 pounds per square inch. A barometer is used to measure atmospheric pressure.

3. Altitude Sickness Altitude sickness—also known as acute mountain sickness (AMS): is a pathological effect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at high altitude. It commonly occurs above 2,400 meters (8,000 feet). It presents as a collection of nonspecific symptoms, acquired at high altitude or in low air pressure, resembling a case of "flu, carbon monoxide poisoning, or a hangover". People have different susceptibilities to altitude sickness; for some otherwise healthy people, acute altitude sickness can begin to appear at around 2000 meters (6,500 ft.) above sea level, such as at many mountain ski resorts. This is the most frequent type of altitude sickness encountered. Symptoms often manifest themselves six to ten hours after ascent and generally subside in one to two days as acclimatization occurs, but they occasionally develop into the more serious conditions (can be fatal). Symptoms include headache, fatigue, stomach illness, dizziness, and sleep disturbance. Exertion aggravates the symptoms. The available amount of oxygen to sustain mental and physical alertness decreases with altitude. Available oxygen drops as the air density drops. Dehydration due to the higher rate of water vapor lost from the lungs at higher altitudes may contribute to the symptoms of altitude sickness. The rate of ascent, altitude attained, amount of physical activity at high altitude, as well as individual susceptibility, are contributing factors to the onset and severity of high-altitude illness.

4. Atmospheric pressure (millibars) Structure and Composition of the Atmosphere 1,000 200 0 400 600 800 120 75 The atmosphere consists of several layers with different temperatures, pressures, and compositions. Temperature 110 65 Thermosphere 100 75-80% of the Earth’s air mass (most of the molecules are here) is found in the troposphere (the layer closest to the Earth). The layer is 11 miles thick at the equator and 5 miles over the poles. Location of Earth’s weather. 90 55 Mesopause 80 Mesosphere 45 70 Altitude (kilometers) Altitude (miles) 60 Stratopause 35 Temperature decreases with altitude until the tropopause, where there is a sudden rise in temperature in the next layer. 50 Stratosphere 40 25 About 99% of the air we breath consist of two gases: Nitrogen 78% Oxygen 21% .01-4% (humid regions) water vapor. .038% Carbon dioxide. Trace amounts of argon, methane, ozone (O3) and nitrous oxide. 30 Tropopause 15 Ozone layer 20 10 Pressure Troposphere 5 (Sea level) 0 –80 80 40 120 –40 0 Temperature (˚C)

5. The Stratosphere and Ozone Layer The stratosphere is the second-lowest layer of Earth's atmosphere. It lies above the troposphere and is separated from it by the tropopause. This layer extends from the top of the troposphere at roughly 11 miles above Earth's surface to the stratopause at an altitude of about 30 miles. The stratosphere has less matter than the troposphere but the composition is almost the same. The atmospheric pressure at the top of the stratosphere is roughly 1/1000 the pressure at sea level. It contains the ozone layer, which is the part of Earth's atmosphere that contains relatively high concentrations of that gas. The stratosphere defines a layer in which temperatures rise with increasing altitude. This rise in temperature is caused by the absorption of ultraviolet radiation (UV) radiation from the Sun by the ozone layer. The stratospheric temperature profile creates very stable atmospheric conditions, so the stratosphere lacks the weather-producing air turbulence that is so prevalent in the troposphere. Consequently, the stratosphere is almost completely free of clouds and other forms of weather.

6. Ozone The stratosphere contains 1000x the ozone of the rest of the atmosphere; ozone forms in an equilibrium reaction when oxygen is converted to O3 by lightning and/or sunlight UV. 3O2 + UV 2O3 This photoprotective layer or “global sunscreen” of ozone keeps 95% of the sun’s harmful UV radiation from reaching the Earth’s surface. The UV filter of the ozone allows us and other forms of life to exist on land and helps to protect us from sunburn, skin and eye cancer, cataracts and damage to the immune system. The ozone layer also keeps oxygen from being converted into photochemical ozone that is harmful when found near the ground.

7. The Mesosphere The mesosphere is the third highest layer of Earth's atmosphere, occupying the region above the stratosphere and below the thermosphere. It extends from the stratopause at an altitude of about 30miles to the mesopause at 50 miles above sea level. Temperatures drop with increasing altitude to the mesopause that marks the top of this middle layer of the atmosphere. It is the coldest place on Earth and has an average temperature around −85 °C. The mesosphere is also the layer where most meteors burn up upon atmospheric entrance. These burning meteors give off a fiery tail that we see from Earth and call shooting stars. It is too high above Earth to be accessible to jet-powered aircraft, and too low to support satellites and orbital or sub-orbital spacecraft.

8. Thermosphere The thermosphereextends from the mesopause (at an altitude 50mi) up to the thermopauseat an altitude range 310–620mi. The temperature of this layer can rise as high as 1,500 °C (2,700 °F), though the gas molecules are so far apart that its temperature in the usual sense is not very meaningful. The air is so rarefied (thin) that an individual molecule travels an average of 1 kilometer between collisions with other molecules.The thermosphere would still feel extremely cold to a human, the few molecules are incapable of transferring an adequate amount of energy to the skin of a human. In other words, a person would not feel warm because of the thermosphere's extremely low pressure. This layer is completely cloudless and free of water vapor. However phenomena such as the aurora borealis and aurora australis are occasionally seen in the thermosphere. The International Space Station orbits in this layer, between 320 and 380 km (200 and 240 mi).

9. Exosphere The exosphereis a thin, atmosphere-like volume surrounding a planetary body where molecules are gravitationally bound to that body, but where the density is too low for them to behave as a gas by colliding with each other. In the case of bodies with substantial atmospheres, such as the Earth's atmosphere, the exosphere is the uppermost layer, where the atmosphere thins out and merges with interplanetary space. It is located directly above the thermosphere. Atmospheric pressure decreases The main gases within the Earth's exosphere are the lightest atmospheric gases, mainly hydrogen, with some helium, carbon dioxide, and atomic oxygen near the base of the exosphere. Since there is no clear boundary between outer space and the exosphere, the exosphere is sometimes considered a part of outer space.

10. Sources of Outdoor Air Pollution Air pollution: the presence of chemicals in the atmosphere in concentrations high enough to harm organisms, ecosystems or human made materials. The effects can range from annoying to lethal. Natural sources of air pollution: Dust blown by wind: Usually large areas of land with few or no vegetation Methane, emitted by the digestion of food by animals, for example cattle. Radon gas from radioactive decay within the Earth's crust. Radon gas from natural sources can accumulate in buildings, especially in confined areas such as the basement and it is the second most frequent cause of lung cancer, after cigarette smoking. Pollutants from wildfires and volcanoes. Smoke and carbon monoxide from wildfires. Volcanic activity, which produces sulfur, chlorine, and ash particulates. Volatile organics released by plants: Vegetation, in some regions, emits environmentally significant amounts of VOCs on warmer days to produce a seasonal haze of secondary pollutants. Most scents or odorsare of VOCs. VOCs play an important role in communication between plants, and messages from plants to animals.

11. Stationary and Mobile Sources Anthropogenic (man-made) sources: These are mostly related to the burning of multiple types of fuel. Stationary Sources include smoke stacks of power plants, manufacturing facilities (factories) and waste incinerators, as well as furnaces and other types of fuel-burning heating devices. In developing and poor countries, traditional biomass burning is the major source of air pollutants; traditional biomass includes wood, crop waste and dung. Mobile Sources include motor vehicles, marine vessels, and aircraft. Waste deposition in landfills, which generate methane. Methane is highly flammable and may form explosive mixtures with air. Methane may displace oxygen in an enclosed space. Asphyxia or suffocation may result if the oxygen concentration is reduced to below 19.5% by displacement. Military resources, such as nuclear weapons, toxic gases, germ warfare and rocketry Fumes from paint, hair spray, varnish, aerosol sprays and other solvents

12. Primary and Secondary Pollution Primary pollution are harmful chemicals that are directly released into the air. While in the atmosphere some primary pollutants react with one another and the air to form secondary pollutants. Primary Pollutants Secondary Pollutants CO CO2 SO2 NO NO2 SO3 Most hydrocarbons HNO3 H2SO4 Most suspended particles H2O2 O3 PANs Most NO3− and SO42− salts Sources Natural Stationary Mobile

13. Types of Outdoor Air Pollutants Major primary pollutants produced by human activity include: 1. Carbon Oxides (Primary): Carbon monoxide (CO)- CO is a colorless, odorless, toxic yet non-irritating gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide. • Carbon dioxide (CO2)-CO2 is a colorless, odorless gas. 93% of carbon dioxide (CO2) in the troposphere occurs as a result of the carbon cycle. 7% of CO2 in the troposphere occurs as a result of human activities (mostly burning fossil fuels). Increasing levels have contributed to global warmingand climate change. Annual fluctuations in CO2 concentration is due to seasonal photosynthetic activity of primary producers like plants. Human health problems: CO stops RBC’s from transporting oxygen efficiently. Chronic exposure can cause heart attacks, lung disease (asthma and emphysema). Can cause headaches, nausea, drowsiness, mental impairment, coma and death. CO detectors are now being required in new homes, before selling a home and for insurance.

14. 2. Nitrogen oxides (primary) and nitric acid (secondary): • Nitrogen oxide (NO) forms when nitrogen and oxygen gas in air react at the high-combustion temperatures in automobile engines and coal-burning plants. NO can also form from lightening and certain soil bacteria (nitrogen fixation part of the nitrogen cycle). • NO reacts with air to form NO2. • Nitrogen dioxide (NO2)reacts with water vapor in the air to form nitric acid (HNO3) and nitrate salts (NO3-) which are components of acid deposition (rain). Both NO and NO2contribute to photochemical smog. Nitrous dioxide N2O is a greenhouse gas emitted from fertilizers and animal wastes. Historical statues also suffer from acid deposition, the Acropolis in Athens has shown great destruction. Human health and other problems : Irritate eyes, nose and throat. Aggravate lungs (asthma and bronchitis) and increase respiratory infections. They can suppress plant growth and reduce visibility. They can be seen as a brown haze dome above or a plume downwind of cities.

15. 3. Sulfur dioxide (SO2 primary) and sulfuric acid (secondary): • Sulfur dioxide (SO2): Colorless gas with a irritating odor. About one-third of SO2 in the troposphere occurs naturally through the sulfur cycle (volcanoes). Two-thirds come from human sources (Anthropogenic ), mostly combustion (S+ O2 SO2) of sulfur-containing coal (electricity) and from oil refining and smelting of sulfide ores. Sulfur dioxide emissions are feeding the Asian Brown Cloud. • SO2 in the atmosphere can be converted to sulfuric acid (H2SO4) and sulfate salts (SO42-) that return to earth as a component of acid deposition (rain). Human health and other problems: Reduce visibility, aggravate breathing problems, damage crops, trees, soils, and aquatic life in lakes. They corrode metals and damage paint, paper, leather and stone buildings and statues.

17. 4. Suspended particulate matter (SPM Primary): • SPM: Consists of a variety of solid particles and liquid droplets small and light enough to remain suspended in the air. Some particulates occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray. Human activities, such as the burning of fossil fuels in vehicles, power plants, various industrial processes, unpaved roads and smokingalso generate significant amounts of SPM. Anthropogenic sources account for 10 % of the atmosphere. Statue Corroded by Acid Deposition and Other Forms of Air Pollution, RI, U.S. • Human health and other problems: The most harmful forms of SPM are fine particles (PM-10, with an average diameter < 10 micrometers) and ultrafine particles (PM-2.5). SPM Irritates eyes, nose and throat. Aggravate lungs and reduce life expectancy. Particulates reduce visibility, corrode metal, discolor clothes and plants. According to the EPA, SPM is responsible for about 60,000 premature deaths a year in the U.S.

18. 5. Ozone (O3 Secondary): Ozone: a colorless, highly reactive gas and is the major cause of photochemical smog. • Human health and other problems: Cause and aggravate respiratory illnessand heart disease, reduce resistance to the common cold and pneumonia, irritate the eyes, nose and throat. Damage plants, rubber in tires, fabrics, and paints. • 6. Volatile organic compounds (VOCs Primary): Are organic compounds that exist as gases in the atmosphere. Most are hydrocarbons emitted by the leaves of many plants and methane. Methane (CH4) is an extremely efficient greenhouse gas which contributes to enhanced global warming. 1/3 of the methane comes from natural sources, plants, wetlands and termites. • About two thirds of global methane emissions comes from anthropogenic sources, primarily rice paddies, landfills, oil and natural gas wells and cows (mainly belching). • Human health and other problems: Long-term exposure to benzene can cause cancer, blood disorders, and immune system damage. 7. Chlorofluorocarbons (CFCs Primary) - harmful to the ozone layer. These are gases which are released from air conditioners, refrigerators, aerosol sprays, etc. CFC's on being released into the air rises to stratosphere. Here they come in contact with other gases and damage the ozone layer. This allows harmful ultraviolet rays to reach the earth's surface. Compounds like CFC, CCl2F2 are also greenhouse gases and are completely anthropogenic (human made). Human health and other problems: This can lead to skin cancer, disease to eye and can even cause damage to plants.

19. Lead in the Environment Because it is a chemical element, lead (Pb) does not break down in the environment. Lead is a potent neurotoxin that can harm the nervous system, is toxic to many organs and tissues including the heart, bones, intestines, kidneys, and reproductive systems especially in young children. Statistics: 12,000-16,000 American children are treated yearly for lead poising and 200 die. 30% of survivors suffer from palsy (refers to various types of paralysis often accompanied by loss of feeling and uncontrolled body movements such as shaking) partial paralysis, blindness, and mental retardation. Any amount of lead in the blood to fetuses and children under 6 can lower IQ by 7.4 points, shorten attention span, hyperactivity, and hearing damage. No level of lead in the blood is safe. The brains of adults who were exposed to lead as children. Areas of volume loss are shown in color.

20. Sources of Lead Past sources of lead in the U.S. Leaded gasoline: Banned in the U.S. in 1976 Lead based paint: Banned in the U.S. in 1970 Increased legislation reduced lead poisoning in children from 85% to 2.2%. Why are children still getting sick? Peeling lead based paint from before the ban and lead contaminated dust in deteriorating or destroyed buildings. In 2007, toy recall as China used lead paint on children’s toys. 2/3 of red lipstick in the U.S. contain high amounts of lead. None of them list lead as an ingredient. Leach from water pipes and faucets when old pipes are still lead. Metaphyseal growth arrest lines are seen in children who experience significant physical stress such as infection, lead poisoning or malnutrition over a sufficient period of time. An X ray demonstrating the characteristic finding of lead poisoning in humans—dense metaphyseal lines

21. The top 20 lead-containing lipsticks from the FDA's 2012 review of 400 lipstick shades

23. Industrial SMOG (Grey) Industrial smog is a mixture of sulfur dioxide, droplets of sulfuric acid, and a variety of suspended solid particles emitted mostly by burning coal and oil. Chemistry of industrial smog: Secondary Primary Some unburned coal ends up as soot in the atmosphere giving the smog a grey color.

24. Industrial SMOG’s Impact • In most developed countries where coal and heavy oil is burned, industrial smog is not a problem due to reasonably good pollution control or with tall smokestacks that transfer the pollutant to rural areas. China relies heavily on coal and has some of the highest levels of industrial smog and 16 of the 20 most polluted cities (Beijing leading the way). In China industrial smog prematurely kills 350,000 people a year (981 per day). Another 250,000 a year die form indoor pollution by burring coal for heating and cooking.

25. Photochemical SMOG (Brown) Sunlight plus Cars Equals Photochemical Smog. A photochemical reaction is any chemical reaction activated by light. Photochemical smog is a mixture of air pollutants formed by the reaction of nitrogen oxides and volatile organic hydrocarbons under the influence of sunlight. Photochemical smog begins as the exhausts from morning commuters release NOx and VOCs (and CO2 but not part of photochemical smog) into the air. The nitrogen containing pollutants give the air a reddish-brown colored smog. Ozone in the troposphere is a greenhouse gas and is formed directly from these photochemical reactions.

26. Photochemical smog is a mixture of ozone, nitric acid, aldehydes, and peroxyacyl nitrates (PANs). NO2, O3 and PANs are photochemical oxidants because these chemicals can react with compounds in your lungs. Contributing factors: Sunny, warm, dry cities with a lot of motor vehicles. Top polluted cities: Los Angeles Salt lake city Denver Sydney Bangkok Jakarta Mexico city

27. Decreasing Outdoor Air Pollution 5 natural factors help reduce outdoor air pollution. Particles heavier than air settle out naturally as a result of gravitational pull. Rain and snow help cleanse the air as particles fall to the Earth with the precipitation. Salty sea spray from the oceans wash out much of the particulates from the air over the oceans. Winds sweep particles away, dilute them with cleaner air, and bring in fresh air. Some pollutants are removed thorough chemical reactions: (SO2 + O2 = SO3 + H20 = H2SO4 Acid deposition).

28. Factors that Increase Air Pollution Six factors that increase outdoor air pollution Urban buildings can slow wind speed and reduce dilution of particles. Hills and mountains can reduce air flow of air in valleys below and allow pollutant levels to build up at ground level. (San Fernando Valley). High temperatures promote the chemical reactions that lead to photochemical smog. Emissions of VOCs from plants like, oaks, poplars, and kudzu in urban areas lead to photochemical smog. Thegrasshopper effect or Global distillation: Pollutants (especially persistent organic compounds POPs) from the lower latitudes hop to the poles where they are deposited. This occurs in the winter and explains why top predators in these areas have high levels of pollutants in their bodies even though most of these chemicals are not used there.

29. 6. Temperature inversions are situations where warmer air traps cooler air and all of the pollution below. (remember warm air rises). Occur in two types of topography: A. Cold, cloudy weather in a valley surrounded by mountains can trap air pollutants. B. Areas with sunny climate, light winds, mountains on three sides and an ocean on the other. Temperature inversion stops atmospheric convection (which is normally present) from happening in the affected area and can lead to the air becoming stiller and murky from the collection of dust and pollutants that are no longer able to be lifted from the surface. This can become a problem in cities where many pollutants exist. Inversion effects occur frequently in big cities such as:Los Angeles, California, Mexico City, Mexico, Mumbai, India, Chengdu, China, Santiago, Chile, São Paulo, Brazil, Tehran, Iran, Vienna, Austria, Milan, Italy, Budapest, Hungary. Descending warm air mass Warmer air Inversion layer Inversion layer Sea breeze Increasing altitude Decreasing temperature In fact, the Chumash tribe of Native Americans actually named Los Angeles the “valley of smoke”.

30. Acid Deposition • Most coal burning power plants, ore smelters, and other industrial plants in developed countries use tall smokestacks to emit sulfur dioxides, nitrogen oxides, and particulates into the atmosphere to produce acidic chemicals that can travel long distances before returning to the earth’s surface. Tall smokestacks reduce local air pollution but can increase regional air pollution. Sulfur dioxide is the number one contributing factor to acid deposition. Wind Acid Rain pH less than5.6 Transformation to sulfuric acid (H2SO4) and nitric acid (HNO3) Windborne ammonia gas and some soil particles partially neutralize acids and form dry sulfate and nitrate salts Wet acid deposition (droplets of H2SO4 and HNO3 dissolved in rain and snow) Nitric oxide (NO) Sulfur dioxide (SO2) and NO Dry acid deposition (sulfur dioxide gas and particles of sulfate and nitrate salts) Acid fog Lakes in shallow soil low in limestone become acidic Lakes in deep soil high in limestone are buffered

31. Harmful Effects of Acid Deposition Human respiratory disease. Damages statues, monuments and buildings, metal and car finishes. Leach toxic metals (lead and mercury) out of soil and rock and deposit them into water used for drinking. In lakes and ponds, biomagnification causes animals to accumulate these metals in their bodies making some fish inedible for humans especially pregnant women and young children. Harms aquatic systems. Most fish cannot live in a pH less than 4.5. Aluminum leached into water can asphyxiate fish as mucus clogs their lungs or cause acid shock. Harm crops (soil pH drops below 5.1). Productivity (photosynthesis) decreases. Harms forests by leaching essential plant nutrients like calcium, and magnesium and depositing mercury, lead, aluminum that weaken the trees and make them vulnerable to disease, insects and drought.

32. Most of the world’s forests are not being destroyed or seriously harmed by acid deposition, rather it is a regional problem harming forests and lakes that lie downwind from large car dominated cities and coal burning facilities without good pollution control.

34. Indoor Air Pollution The most threatening indoor air pollutants are smoke and soot from wood and coal cooking fires (a hazard found mostly in developing countries) and chemicals used in building materials and products. Indoor air pollution usually is a greater threat to human health than outdoor air pollution. If you are reading this lecture inside you are probably inhaling more air pollutant than you would outside. According to the WHO, indoor pollution is, for poor people, the world’s most serious pollution problem. • According to the EPA, the four most dangerous indoor air pollutants in developed countries are: • Tobacco smoke. • Formaldehyde. • Radioactive radon-222 gas. • Very small fine and ultrafine particles.

35. Indoor Pollutants 1. Levels of 11 common pollutants are 2-5 times greater indoors. 2. Pollution inside your car when stuck in traffic can become 18 times greater than outside the car. 3. The health risks is magnified in developed contrives because people spend 70-98% of their time indoors. Household dust mites that feed on human skin and dust, live in materials such as bedding and furniture fabrics. Along with dust mites, cockroach droppings Can cause asthma attacks and allergic reactions in some people. Airborne spores of molds, fungal growths and mildew can aggravate asthma, allergies, cause headaches and grows in walls and under houses where it is damp. It is the single greatest cause of allergic reactions to indoor air. Radon-222, a radioactive gas found in some soils and rocks, can seep into some houses and increase the risk of lung cancer. Comes from natural radioactive decay that seeps into homes.

36. Sources and Paths of Entry for Indoor Radon-222 Gas The best way to protect your home from radon gas is to seal areas where radon enters or ventilate the area with window or vents. Most radon that enters homes comes from the decay of underlying bedrock.

37. Chloroform Para-dichlorobenzene Tetrachloroethylene Source: Chlorine-treated water in hot showers Possible threat: Cancer Source: Air fresheners, mothball crystals Threat: Cancer Source: Dry-cleaning fluid fumes on clothes Threat: Nerve disorders, damage to liver and kidneys, possible cancer Formaldehyde Source: Furniture stuffing, paneling, particleboard, foam insulation Threat: Irritation of eyes, throat, skin, and lungs; nausea; dizziness 1,1,1-Trichloroethane Source: Aerosol sprays Threat: Dizziness, irregular breathing Styrene Nitrogen oxides Source: Carpets, plastic products Threat: Kidney and liver damage Source: Unvented gas stoves and kerosene heaters, woodstoves Threat: Irritated lungs, children's colds, headaches Benzo- α -pyrene Source: Tobacco smoke, woodstoves Threat: Lung cancer Particulates Source: Pollen, pet dander, dust mites, cooking smoke particles Threat: Irritated lungs, asthma attacks, itchy eyes, runny nose, lung disease Radon-222 Source: Radioactive soil and rock surrounding foundation, water supply Threat: Lung cancer Tobacco smoke Source: Cigarettes Threat: Lung cancer, respiratory ailments, heart disease Asbestos Methylene chloride Carbon monoxide Source: Pipe insulation, vinyl ceiling and floor tiles Threat: Lung disease, lung cancer Source: Faulty furnaces, unvented gas stoves and kerosene heaters, woodstoves Threat: Headaches, drowsiness, irregular heartbeat, death Source: Paint strippers and thinners Threat: Nerve disorders, diabetes

38. Health Effects of Air Pollution Air pollution can contribute to asthma, chronic bronchitis, emphysema, lung cancer, heart attack, and stroke. The respiratorysystem’s defenses against air pollution: Hairs in your nose filter out large particles. Mucous lining in the upper respiratory tract captures small particles. Sneezing and coughing help expel the trapped particles. The respiratory tract is lined with tiny hairs called cilia that move particles and mucous to the throat to be swallowed or expelled. Prolonged exposure to fine and ultrafine air pollutants (including tobacco smoke) can overload our defenses. In the U.S. 17 million people suffer from asthma and 14 die from it each day.

39. Lung Diseases Chronic obstructive pulmonary disease (COPD), among others, is a type of obstructive lung disease characterized by chronically poor airflow. It typically worsens over time. The main symptoms include shortness of breath, cough, and sputum production. Tobacco smoking is the most common cause of COPD, with a number of other factors such as air pollution and genetics playing a smaller role. Normal lungs Long-term exposure to irritants causes an inflammatory response in the lungs resulting in narrowing of the small airways and breakdown of lung tissue known as emphysema. The diagnosis is based on poor airflow as measured by lung function tests. In contrast to asthma, the airflow reduction does not improve significantly with the administration of medication. Lungs of a person who died of emphysema

40. Sick Buildings Americans spend more than 90 percent of their time indoors. Sick building syndrome (SBS) is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. A 1984 World Health Organization report suggested up to 20-30% of new and remodeled buildings worldwide may be subject of complaints related to poor indoor air quality. Sick building causes are frequently pinned down to flaws in the heating, ventilation, and air conditioning (HVAC) systems. Other causes have been attributed to contaminants produced by outgassing of some types of building materials, volatile organic compounds (VOC), molds, improper exhaust ventilation of ozone (byproduct of some office machinery), light industrial chemicals used within, or lack of adequate fresh-air intake/air filtration Human exposure to bioaerosols has been documented to give rise to a variety of adverse health effects.Building occupants complain of symptoms such as sensory irritation of the eyes, nose, throat; neurotoxic or general health problems; skin irritation; nonspecific hypersensitivityreactions; headache, depression, dizziness; infectious diseases; and odor and taste sensations.

41. Air Pollution is a Big Killer Each year, air pollution prematurely kills about 3 million people, mostly from indoor air pollution in developing countries. • In the U.S., the EPA estimates that annual deaths related to indoor and outdoor air pollution range from 150,000 to 350,000. • According to the EPA, each year more than 125,000 Americans get cancer from breathing diesel fumes. These are related to concentrations of coal burning plants.

42. Air Quality Laws and Regulations Legal, economic, and technological tools can help to clean up air pollution, but much greater emphasis should be focused on preventing air pollution. The Clean Air Act(1970, 1977, 1990) is a United States federal law designed to control air pollution on a national level. It requires the Environmental Protection Agency (EPA) to develop and enforce regulations to protect the public from airborne contaminants known to be hazardous to human health. The National Ambient Air Quality Standards (NAAQS) are standards established by the United StatesEnvironmental Protection Agency under authority of the Clean Air Actthat apply for outdoor air throughout the country. Primary standards are designed to protect human health especially sensitive populations such as children, the elderly, and individuals suffering from respiratory diseases. Accomplishment of the CAA since 1970: Particulate Matter (PM)- down 78% Carbon Dioxide (CO2)- down 23% Nitrogen Dioxide (Nox)- up 14% Lead (Pb)- down 98% Sulfur Dioxide (SO2)- down 32% Air quality is worse in developing countries: Mexico City & Beijing: air exceeds WHO standards 350 days/year • Focus of the CAA and NAAQS • Carbon monoxide • Nitrogen oxides • Sulfur dioxides • Suspended particulate matter • (less than PM-10) • Ozone • Lead

43. Clean Air Act Emission Trading To help reduce SO2 emissions, the Clean Air Act authorized an emission trading (cap-and-trade) program. • Enables the 110 most polluting power plants to buy and sell SO2 pollution rights. • Each year these coal burning plants are given a set number of pollution credits. Each year extra pollution credits can be: Given to other of the companies plants. Keep for future plant expansions Sell them to other companies, private citizens or environmental groups. • Between 1990-2006, the emission trading system reduced emissions. However, the EPA reported the cap-and-trade system produced less emission reductions than were projected.

44. Reducing Outdoor Air Pollution There are a number of ways to prevent and control air pollution from coal-burning facilities. • Electrostatic precipitator: are used to attract negatively charged particles in a smokestack into a collector. Used to keep particulates from being emitted into the air. • Wet scrubber: fine mists of water vapor trap particulates and convert them to a sludge that is collected and disposed of usually in a landfill. Used to reduce SO2 emissions.

45. There are a number of ways to prevent and control air pollution from motor vehicles. • Because of the Clean Air Act, a new car today in the U.S. emits 75% less pollution than did pre-1970 cars. • There is and increase in motor vehicle use in developing countries and many have no pollution control devices and burn leaded gasoline.

46. Reducing Indoor Air Pollution

47. Little effort has been devoted to reducing indoor air pollution even though it poses a much greater threat to human health than outdoor air pollution. Environmental and health scientists call for us to focus on preventing air pollution (especially indoor) in developing countries.

48. Need to be more Emphasis on Prevention

49. I thought I saw a blue jay this morning. But the smog was so bad that it turned out to be a cardinal holding its breath. Michael J Cohen

50. Climate Change (19) The overwhelming scientific consensus is that the earth’s atmosphere is warming rapidly, mostly because of human activities, and that this will lead to significant climate change during this century. Global warming and cooling are not new. Changes in the Earth’s climate over the past 4.5 billion years is not unusual. The planets climate has been altered by: Volcanic emissions Changes in solar input Continents slowly moving Impacts of meteors When volcanoes erupt, they emit a mixture of gases and particles into the air. Some of them, such as ash and sulfur dioxide, have a cooling effect, because they (or the substances they cause) reflect sunlight away from the earth. Others, such as CO2, cause warming by adding to the greenhouse effect. Although volcanoes emit carbon dioxide they have a greater cooling effect on the Earth. The cooling influence is particularly marked in the case of large eruptions able to blast sun-blocking particles all the way up to the stratosphere – such as Mount Pinatubo in 1991, which caused a significant dip in global temperatures in the following year or two.