Air Pollution Chapter 18.

Air Pollution Chapter 18

Core Case Study: South Asia’s Massive Brown Cloud
Asian Brown Cloud Causes clearing and burning forest for planting crops Burning of coal, diesel, and other fossil fuels in industries , vehicles and homes Chemical composition 1/3rd of it is dust, smoke, and ash Rest is acidic compounds, soot, toxic metals (mercury and lead), hundreds of organic compounds and fly ash Areas impacted much of India, Bangladesh, the industrial heart of China, the Open Sea east of this area Photosynthesis has been reduced by 7-10% Acid in the haze fall to the surface and damage crops, trees, and aquatic life

The Asian Brown Cloud Air pollution connects the world
On certain days 25% of particulate matter 77% of black carbon 33% of toxic mercury in the skies above LA can be traced to China Steps taken in China and India to reduce air pollution strict pollution controls standards for coal-burning industries shifting from coal to cleaner burning natural gas

Air Pollution in Shanghai, China, in 2004

18-1 The Atmosphere Consists of Several Layers
Atmosphere varies in Density The air we breathe at sea level is denser than the air on top of the world’s highest mountains. Atmospheric pressure Decreases with altitude because they are fewer gas molecules at higher levels

Earth’s Atmosphere Compared to the size of the Earth (12000 km)
Shuttle Images of the Atmosphere These images highlight the difference in the atmosphere before and after the. Showing the earth’s limb at sunset, first in September 1984, the atmosphere is relatively clear. The second image, taken in August of 1991, a little more than a month after the eruption, shows distinct layers of aerosols in the upper reaches of the atmosphere. These aerosols eventually made their way around the globe, contributing to a temporary worldwide cooling. Images Courtesy: NASA/ JSC June 15, 1991 the eruption of Mt. Pinatubo, one of the most destructive volcanic eruptions of the last century. Found on the Bataan Peninsula on the island of Luzon in the Philippines, the volcano had been dormant for 500 years when clouds of sulfur dioxide and tons of ash spewed from the crater. Ultimately over 600 lives were lost in the explosion and its aftermath. Compared to the size of the Earth (12000 km) The atmosphere is very thin (120 km) or (75 miles) After Mt. Pinatubo eruption 1991

Atmospheric Layers Aurora, caused by collisions between protons and electrons from the Sun and oxygen and nitrogen atoms in the atmosphere. Thermosphere This layer extends as high as 1000 km. Temperature increases rapidly after about 88 km. Meteor burning up The atmosphere consists of layers around the Earth, each one defined by the way temperature changes within its limits. The layer boundaries are: Tropopause Stratopause Mesopause The outermost, the thermosphere, thins slowly, fading into space with no boundary. Mesosphere Temperature is constant in the lower mesosphere, but decreases steadily with height above 56 km. Stratosphere Temperature is stable to 20 km, then increases due to absorption of UV by the thin layer of ozone. Troposphere Air mixes vertically and horizontally. All weather occurs in this layer.

Air Movements in the Troposphere Play a Key Role in Earth’s Weather and Climate
This is where we live 8 to 14.5 kilometers high (5 to 9 miles) the temperature drops from about 17 to -52 degrees Celsius 75–80% of the earth’s air mass most dense Closet to the earth's surface Rising and falling air currents: weather and climate Involved in chemical cycling

Composition Nitrogen (N2, 78%) Oxygen (O2, 21%) Argon (Ar, 1%)
myriad of other very influential components are also present which include the Water (H2O, 0 - 7%), "greenhouse" gases or Ozone (O3, %), Carbon Dioxide (CO2, %),

The Stratosphere Is Our Global Sunscreen
extends to 50 kilometers (31 miles) high dry and less dense temperature in this region increases gradually to -3 degrees Celsius, due to the absorption of ultraviolet radiation ozone layer absorbs and scatters the solar ultraviolet radiation ninety-nine percent of "air" is located in first two layers every 1000-m 11% less air pressure Similar composition to the troposphere, with 2 exceptions Much less water O3, ozone layer, filters UV

Natural Capital: The Earth’s Atmosphere Is a Dynamic System with Four Layers
Figure 18.3 Natural capital: The earth’s atmosphere is a dynamic system that includes four layers. The average temperature of the atmosphere varies with altitude (red line). Most UV radiation from the sun is absorbed by ozone (O3), found primarily in the stratosphere in the ozone layer 17–26 kilometers (10–16 miles) above sea level. Question: Why do you think the temperature falls and rises twice, going from lower to higher altitudes?

O3 -The Good, the Bad, and the Ugly

O3 -The Good (15 - 40 km) blocks solar UV l<290 nm
Beneficial Ozone that forms in the stratosphere protects life on earth by filtering out most of the incoming harmful UV radiation emitted by the sun

O3 -The Bad 6-10 km : greenhouse gas absorbs IR emitted by Earth
O3 →O3 (v=1) Harmful or Photochemical ozone forms in the troposphere when various air pollutants undergo chemical reactions under the influence of sunlight. Ozone in the atmosphere near the earth’s surface damages plants, lung tissue, and some materials such as rubber. It is a strong oxidant and respiratory irritant. Ground level ozone results primarily from motor-vehicle exhaust

O3 -The Ugly part of smog (bad, too)

18-2 Air Pollution Comes from Natural and Human Sources
The presence of chemicals in the atmosphere in concentrations high enough to harm organisms, ecosystems, or human-made material. Natural sources Dust blown by wind Pollutants from wildfires and volcanoes Volatile organics released by plants Withdrawing groundwater

Air Pollution Comes from Natural and Human Sources
Human sources: mostly in industrialized and/or urban areas Stationary sources Mobile sources

Sources and Types of Air Pollutants

Most suspended particles H2O2 O3 PANs Most NO3− and SO42− salts
Primary Pollutants Secondary Pollutants CO CO2 SO2 NO NO2 Most hydrocarbons SO3 HNO3 H2SO4 Most suspended particles H2O2 O3 PANs Most NO3− and SO42− salts Sources Natural Stationary Figure 18.4 Sources and types of air pollutants. Human inputs of air pollutants come from mobile sources (such as cars) and stationary sources (such as industrial and power plants). Some primary air pollutants react with one another and with other chemicals in the air to form secondary air pollutants. Mobile Fig. 18-4, p. 472

Case Study: Air Pollution in the Past: The Bad Old Days
Discovery of fire Middle Ages 1700’s - Industrial Revolution London, England 1850s dense mixture of coal smoke and fog 1880- a prolonged coal fog killed an estimated 2,200 people 1952: yellow fog lasted for 5 days and killed 4, ,000 Londoners Clean Air Act of 1956

Case Study: Air Pollution in the Past: The Bad Old Days (2)
United States 1948: Donora, PA; first U.S. air pollution disaster 1963: New York City Global problem Urban areas in China, India and parts of Eastern Europe that depend on coal in industries and in some homes face air pollution levels similar to those in London and America in the 1950’s

Some Pollutants in the Atmosphere Combine to Form Other Pollutants
Primary pollutants Are harmful chemicals emitted directly into the air from natural processes and human activities. Secondary pollutants Primary pollutants react with one another and with the basic components of air to form new harmful chemicals Air quality improving in developed countries Much more needs to be done in developing countries Indoor pollution: big threat to the poor

Indoor Air Pollution These children are working in a plastic factory in an urban slum in Bangladesh.

What Are the Major Outdoor Air Pollutants?
Carbon oxides Carbon monoxide (CO) Colorless and highly toxic that forms during the incomplete combustion of carbon-containing materials. Reacts with hemoglobin in blood cells reduces the ability to transport oxygen. Sources Motor vehicles exhaust, burning of forest and grasslands, tobacco smoke, and open fires and inefficient stoves used for cooking. Carbon dioxide (CO2) Colorless, odorless gas. 93% result of natural carbon cycle Rest from burning fossil fuels and clearing CO2 absorbing forest and grasslands. Emissions have been rising since the industrial revolution

Nitrogen oxides (NO) and nitric acid (HNO3) Sources- automobiles, coal-burning plants NO reacts with oxygen to form NO2 (reddish brown gas) NO and NO2 are collectively called NOx Acid deposition Photochemical smog Human health and environmental impact Nitrous oxide (N2O) a greenhouse gas that is emitted from fertilizers and animal waste and by burning fossil fuels

Major Outdoor Pollutants
Sulfur dioxide (SO2) and sulfuric acid (H2SO4) Description: Colorless, irritating; forms mostly from the combustion of sulfur containing fossil fuels such as coal and oil (S + O2 SO2); in the atmosphere can be converted to sulfuric acid (H2SO4), a major component of acid deposition. Major human sources: Coal burning in power plants (88%) and industrial processes (10%). Health effects: Breathing problems for healthy people; restriction of airways in people with asthma; chronic exposure can cause a permanent condition similar to bronchitis. According to the WHO, at least 625 million people are exposed to unsafe levels of sulfur dioxide from fossil fuel burning. Environmental effects: Reduces visibility; acid deposition of H2SO4 can damage trees, soils, and aquatic life in lakes. Property damage: SO2 and H2SO4 can corrode metals and eat away stone on buildings, statues, and monuments; SO2 can damage paint, paper, and leather.

Particulates Suspended particulate matter (SPM) Variety of particles and droplets (aerosols) small and light enough to remain suspended in atmosphere for short periods (large particles) to long periods cause smoke, dust, and haze. Sources Burning coal in power and industrial plants (40%), burning diesel and other fuels in vehicles (17%), agriculture (plowing, burning off fields), unpaved roads, construction. Human health and environmental impact Nose and throat irritation, lung damage, and bronchitis; aggravates bronchitis and asthma; shortens life; toxic particulates (such as lead, cadmium, PCBs, and dioxins) can cause mutations, reproductive problems, cancer. Reduces visibility; acid deposition of H2SO4 droplets can damage trees, soils, and aquatic life in lakes

Suspended particulate matter consists of particles of solid matter and droplets of liquid, that are small and light enough to remain suspended in the atmosphere for period (larger the particle, the sooner it falls to earth). Suspended particles are found in a wide variety of types and sizes, ranging in diameter from micrometer to 100 micrometers ( a micrometer, or micron, is one millionth of a meter, or about inch) Since 1987, the EPA has focused on fine particles smaller than 10 microns ( known as PM-10). In 1997, the agency began focusing on reducing emissions of ultra fine particles w/ diameters less than 2.5 microns ( known as PM-2.5) because these particles are small enough to reach the lower part of the human lungs and contribute to respiratory disease.

Ozone (O3) Highly reactive, irritating gas with an unpleasant odor that forms in the troposphere as a major component of photochemical smog Sources Chemical reaction with volatile organic compounds (VOCs, emitted mostly by cars and industries) and nitrogen oxides to form photochemical smog Human and environmental impact Breathing problems; coughing; eye, nose, and throat irritation; aggravates chronic diseases such as asthma, bronchitis, emphysema, and heart disease; reduces resistance to colds and pneumonia; may speed up lung tissue aging. Environmental effects: Ozone can damage plants and trees; smog can reduce visibility. Property damage: Damages rubber, fabrics, and paints.

Volatile organic compounds (VOCs) organic compounds (hydrocarbons) that evaporate easily, usually aromatic Hydrocarbons and terpenes Sources Methane, chlorofluorocarbon, benzene and proprane. vehicles (largest source), evaporation of solvents or fossil fuels, aerosols, paint thinners, dry cleaning Human and environmental impact eye and respiratory irritants; carcinogenic; liver, CNS, or kidney damage; damages plants; lowered visibility due to brown haze; global warming

Chemical Reactions That Form Major Outdoor Air Pollutants

Statue Corroded by Acid Deposition and Other Forms of Air Pollution, RI, U.S.

Natural Capital: Lichen Species, Vulnerability to Air Pollutants
Red and yellow crustose lichens growing on slate rock in the foothills of the Sierra Nevada near Merced, California. 19th century coal miners took canaries w/ them into the mines- canaries stop singing when the air contained methane, which could ignite and explode. Lichens, which are not plants, consist of a fungus and an alga living together, usually in a mutually beneficial (mutualistic) partnership. These hardy pioneer species are are good biological indicators of air pollution because they are always absorbing air as a source of nourishment. A highly polluted area around an industrial plant may have no lichens or only gray-green crusty lichens. An area w/ moderate pollution may have orange crusty lichens on walls. Walls and trees in areas with fairly clean air may have leafy lichens. Because lichens are widespread, long lived, and anchored in place, they can also help track pollution to its source. Case Study: When is a Lichen Like a Canary

Case Study: Lead Is a Highly Toxic Pollutant
Does not break down in the environment Solid toxic metal and its compounds, emitted into the atmosphere as particulate matter. Sources Paint old houses), smelters (metal refineries), lead manufacture, storage batteries, leaded gasoline (being phased out in developed countries). Human health and environmental impact Accumulates in the body; brain and other nervous system damage and mental retardation (especially in children); digestive and other health problems; some lead-containing chemicals cause cancer in test animals. Can harm wildlife.

Case Study: Lead Is a Highly Toxic Pollutant
Reduction of lead (Pb) Unleaded gasoline Unleaded paint 1960 Still problems 2007: toys with Pb paint recalled 2007 2/3rd of red long-lasting lipstick manufactured in the US contained surprisingly high levels of lead. Global ban on lead in gasoline and paint

SOLUTIONS Lead Poisoning Prevention Control
Phase out leaded gasoline worldwide Replace lead pipes and plumbing fixtures containing lead solder Phase out waste incineration Remove leaded paint and lead dust from older houses and apartments Ban use of lead solder Sharply reduce lead emissions from incinerators Ban use of lead in computer and TV monitors Remove lead from TV sets and computer monitors before incineration or land disposal Ban lead glazing for ceramicware used to serve food Figure 18.7 Ways to help protect children from lead poisoning. Question: Which two of these solutions do you think are the most important? Why? Test for lead in existing ceramicware used to serve food Ban candles with lead cores Test existing candles for lead Test blood for lead by age 1 Wash fresh fruits and vegetables Fig. 18-7, p. 476

Burning Coal Produces Industrial Smog
Chemical composition of industrial smog mixture of SO2, droplets of sulfuric acid, and a variety of suspended solid particles emitted by burning coal Reduction of this smog in urban cities of the United States China and smog

How Pollutants Are Formed from Burning Coal and Oil, Leading to Industrial Smog

Carbon monoxide (CO) and
Ammonium sulfate [(NH4)2SO4] Ammonia (NH3) Sulfuric acid (H2SO4) Water vapor (H2O) Carbon monoxide (CO) and carbon dioxide (CO2) Sulfur trioxide (SO 3 ) Oxygen (O2) Sulfur dioxide (SO2) Burning coal and oil Oxygen (O2) Figure 18.8 How pollutants are formed from burning of coal and oil. The result is industrial smog (Concept 18-2). Sulfur (S) in coal and oil Carbon (C) in coal and oil Fig. 18-8, p. 476

Carbon monoxide (CO) and
Ammonium sulfate [(NH4)2SO4] Ammonia (NH3) Sulfuric acid (H2SO4) Water vapor (H2O) Sulfur trioxide (SO 3 ) Oxygen (O2) Sulfur dioxide (SO2) Sulfur (S) in coal and oil Carbon monoxide (CO) and carbon dioxide (CO2) Carbon (C) in coal and oil Burning coal and oil Oxygen (O2) Figure 18.8 How pollutants are formed from burning of coal and oil. The result is industrial smog (Concept 18-2). Stepped Art Fig. 18-8, p. 476

Sunlight Plus Cars Equals Photochemical Smog
Chemical composition is a mixture of air pollutants formed by the reaction of nitrogen oxides and volatile organic hydrocarbon compounds under the influence of light VOCs + NO2 + Heat + Sunlight yields Ground level O3 and other photochemical oxidants Aldehydes Other secondary pollutants

A Model of How Pollutants That Make Up Photochemicals Are Formed

Nitric oxide (NO) + Oxygen atom (O)
PANS and other pollutants Volatile organic compounds (VOCs) Ozone (O3) Oxygen (O2) Nitric oxide (NO) + Oxygen atom (O) Water vapor (H2O) Hydrocarbons UV radiation Peroxyacyl nitrates (PANs) Nitrogen dioxide (NO2) Oxygen (O2) Nitric oxide (NO) Figure 18.9 A greatly simplified model of how pollutants that make up photochemical smog are formed. Oxygen (O2) Burning fossil fuels Nitrogen (N) in fossil fuel Fig. 18-9, p. 477

Global Outlook: Photochemical Smog in Santiago, Chile

How can trees Contribute to Photochemical Smog?
Trees certainly have environmental benefits Emit oxygen, absorb CO2, provide shade, and help absorb and remove various pollutants from the air. Some trees (some oak species, sweet gums, Poplars, and Kudzu) in and around urban areas play a large role in smog formation They emit VOCs (like isoprene) that are ingredients in the development of photochemical smog. Plants in urban areas should be trees that emit low levels of VOCs.

Several Factors Can Decrease or Increase Outdoor Air Pollution
Outdoor air pollution may be decreased by Settling of particles due to gravity Rain and snow Salty sea spray from the ocean Winds Chemical reactions

Several Factors Can Decrease or Increase Outdoor Air Pollution
Outdoor air pollution may be increased by Urban buildings Hills and mountains High temperatures Emissions of VOCs from certain trees and plants Grasshopper effect Temperature inversions

A Temperature Inversion

Descending warm air mass
Warmer air Descending warm air mass Inversion layer Inversion layer Sea breeze Increasing altitude Figure 18.11 A temperature inversion, in which a warm air layer sits atop a cooler air layer, can take place in either of two sets of topography and weather conditions. Air pollutants can build to harmful levels during an inversion, which can occur during cold, cloudy weather in a valley surrounded by mountains (left). Frequent and prolonged temperature inversions can also occur in an area with a sunny climate, light winds, mountains on three sides, and the ocean on the other (right). A layer of descending warm air from a high-pressure system prevents ocean-cooled air near the ground from ascending enough to disperse and dilute pollutants. Because of their topography, Los Angeles, California (USA), and Mexico City, Mexico, have frequent temperature inversions, many of them prolonged, during the summer and fall. Decreasing temperature Fig , p. 478

Animation: Formation of photochemical smog

Animation: Thermal inversion and smog

18-3 Acid Disposition Is a Serious Regional Air Pollution Problem
Acid deposition, acid rain Local versus regional problems Tall smokestacks reduce local air pollution by increases region air pollution downwind Effects of prevailing winds Where is the worst acid deposition?

Acid Deposition Formation
When gas pollutants e.g. carbon dioxide, sulfur dioxide, nitrogen dioxide dissolve in rain water, various acids are formed. CO2 + H2O  H2CO3 (carbonic acid) SO2 + H2O  H2SO3 (sulfurous acid) NO2 + H2O  HNO2 (nitrous acid) HNO3 (nitric acid) Sulfuric acid is responsible for about two-thirds of the acid deposition damage in the world and nitric acid the remaining one-third. In urban areas where NOx are released by the numerous vehicles, the damage from each type is nearly equal.

Causes of Acid Rain Sulfur dioxide (SO2) and nitrogen oxides (NOx) are the primary causes of acid rain. In the US, About 2/3 of all SO2 and 1/4 of all NOx comes from electric power generation that relies on burning fossil fuels like coal.

Natural Capital Degradation: Acid Deposition, Acid Rain

pH measurements in relation to major coal-burning and industrial plants. (Normal rain has a pH of 5.6)

Current and Possible Future Acid Rain Problem Areas

Figure 18.13 Regions where acid deposition is now a problem and regions with the potential to develop this problem (Concept 18-3). Such regions have large inputs of air pollution (mostly from power plants, industrial plants, and ore smelters) or are sensitive areas with soils and bedrock that cannot neutralize (buffer) inputs of acidic compounds. Question: Do you live in or near an area that is affected by acid deposition or any area that is likely to be affected by acid deposition in the future? (Data from World Resources Institute and U.S. Environmental Protection Agency) Potential problem areas because of sensitive soils Potential problem areas because of air pollution: emissions leading to acid deposition Current problem areas (including lakes and rivers) Fig , p. 480

Increased Acidity Dry deposited gases and particles can also be washed from trees and other surfaces by rainstorms. The runoff water adds those acids to the acid rain, making the combination more acidic than the falling rain alone.

Effects of Acid Rain Has a variety of effects, including damage to forests and soils, fish and other living things, materials, and human health. Also reduces how far and how clearly we can see through the air, an effect called visibility reduction. Effects of acid rain are most clearly seen in the aquatic environments Most lakes and streams have a pH between 6 and 8

Buffering Capacity Acid rain primarily affects sensitive bodies of water, which are located in watersheds whose soils have a limited “buffering capacity” Lakes and streams become acidic when the water itself and its surrounding soil cannot buffer the acid rain enough to neutralize it.

In areas where buffering capacity is low, acid rain also releases aluminum ions from soils into lakes and streams; aluminum is highly toxic to many species of aquatic organisms referred to as acid shock.

Effects on Wildlife Generally, the young of most species are more sensitive to environmental conditions than adults. At pH 5, most fish eggs cannot hatch. At lower pH levels, some adult fish die. Some acid lakes have no fish. The eggs and juveniles of sensitive species are susceptible to a pH of 5, thus interfering w/ reproduction. The acids therefore decrease biodiversity by reducing food available at lower trophic levels, which may have a resultant reduction of biomass. Sensitive fish species include trout and salmon. Trash fish species, such as gar, and carp, are more pollutant tolerant.

Acid Rain and Forests Acid rain does not usually kill trees directly.
Instead, it is more likely to weaken trees by damaging their leaves, limiting the nutrients available to them, or exposing them to toxic substances slowly released from the soil. Vegetation is impacted by acid deposition. Acid directly damages cuticles (the waxy coat on leaves) on plant leaves, which makes the plants more susceptible to infections from bacteria, nematodes, and fungi. As a result, not only are forest damaged, but crop yields are reduced in acidified ecosytesms. .

Mongolia Germany Forest damage is exemplified by the devastation in the Black forest in Germany.

Great Smoky Mountains, NC
Effects of Acid Rain Forest damage is exemplified by the devastation in the Great Smokey Mountains in the U.S. Great Smoky Mountains, NC

Nutrients Acidic water dissolves the nutrients and helpful minerals in the soil and then washes them away before trees and other plants can use them to grow. Acid rain also causes the release of substances that are toxic to trees and plants, such as aluminum, into the soil.

Acid Deposition Has a Number of Harmful Effects
Human respiratory disorders Aquatic ecosystems affected Release of toxic metal Toxic lead and mercury Leaching of soil nutrients Loss of crops and trees Damage to buildings, statues, and monuments

Natural Capital Degradation: Air Pollution Damage to Trees in North Carolina, U.S.

Solutions: Acid Deposition, Prevention and Cleanup

Active Figure: Acid deposition

Video: Air pollution in China

Active Figure: Effect of air pollution in forests

18-4 Indoor Air Pollution Is a Serious Problem
Developing countries Indoor burning of wood, charcoal, dung, crop residues, coal in open fires or unvented or poorly vented stoves Poor suffer the greatest risk Developed countries Indoor air pollution is greater than outdoor air pollution

Exposure Time spent in various environments in US and less-developed countries

Indoor Air Pollution Is a Serious Problem
Why? 11 of the common air pollutants higher inside than outside Greater in vehicles than outside Health risks magnified: people spend 70–98% of their time is indoors

Who are at greatest risk from indoor air pollution? Children under 5 and the elderly Sick Pregnant women People with respiratory disorders or heart problems Smokers Factory workers

Four most dangerous indoor air pollutants Tobacco smoke- most preventable Formaldehyde Found in many building material, and household products (plywood, particle board, paneling, high-gloss wood, drapes, furniture, carpets, wallpaper, wrinkle- free coating on permanent –press clothing) The chemical that causes most people in developed countries difficulty Colorless extremely irritating chemical Causes chronic breathing problems, dizziness, skin, eye, sinus irritation, rash, headaches, sore throats, wheezing and nausea EPA estimates that 1 of every 5,000 people who live in manufactured homes for more than 10 years will develop cancer from formaldehyde exposure.

Four most dangerous indoor air pollutants (cont)
Radioactive radon-222 gas Seep into houses from underground rock deposits Colorless odorless radioactive gas produced by the natural decay of uranium-238. lung tissue damage, 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 Very small particles Asbestos Irritate the nose and throat, damage the lungs, aggravate asthma and bronchitis, and shorten life.

Science: Sources and Paths of Entry for Indoor Radon-222 Gas

(From: http://www.epa.gov/iaq/radon/zonemap.html)
Zone pCi/L >4 <2

Other possible indoor air pollutants Pesticide residue Pb particles Living organisms and their excrements E.g., Dust mites and cockroach droppings Airborne spores of molds and mildews

Science: Magnified View of a Household Dust Mite in a Dust Ball

Some Important Indoor Air Pollutants

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 Figure 18.16 Some important indoor air pollutants (Concept 18-4). Question: Which of these pollutants are you exposed to? (Data from U.S. Environmental Protection Agency) Tobacco smoke Source: Cigarettes Threat: Lung cancer, respiratory ailments, heart disease Asbestos Carbon monoxide Methylene chloride 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 Fig , p. 484

Sick Building Syndrome (SBS) vs Building Related Illness (BRI)

Sick Building Syndrome
A persistent set of symptoms in > 20% population Causes(s) not known or recognizable Complaints/Symptoms relieved after exiting building Linked to inadequate ventilation, new buildings that contain chemicals such as formaldehyde from building products, or biological contaminants like mold or pollen.

Complaints/Symptoms Headaches Fatigue Reduced Mentation Irritability
Eye, nose or throat irritation Dry Skin Nasal Congestion Difficulty Breathing Nose Bleeds Nausea

Building Related Illness
Clinically Recognized Disease Exposure to indoor air pollutants Recognizable Causes

Clinically Recognized Diseases
Pontiac Fever – Legionella spp. Legionnaire's Disease Hypersensitivity Pneumonitis Humidifier Fever Asthma Allergy Respiratory Disease Chronic Obstructive Pulmonary Disease

Respiratory system protection from air pollutants
18-5 Your Body’s Natural Defenses against Air Pollution Can Be Overwhelmed Respiratory system protection from air pollutants Hair in nose, cilia, mucus, sneezing, and coughing Effect of smoking and prolonged air pollution exposure Chronic bronchitis Emphysema- irreversible damage to the air sacs in the lungs

Major Components of the Human Respiratory System

Normal Human Lungs and the Lungs of a Person Who Died of Emphysema

Air Pollution Is a Big Killer
3 Million deaths per year world-wide Mostly in Asia Main causes Heart attacks, respiratory diseases, and lung cancer EPA: proposed stricter emission standards for diesel-powered vehicles Link between international trade and air pollution Cargo ships and pollution

Premature Deaths from Air Pollution in the U.S.

18-6 Laws and Regulations Can Reduce Outdoor Air Pollution (1)
United States Clean Air Acts: 1970, 1977, and 1990 EPA National ambient air quality standards (NAAQs) for 6 outdoor criteria pollutants National emission standards for 188 hazardous air pollutants (HAPs) Toxic Release Inventory (TRI)

1970 – Uniform Standards by Federal Govt.
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

Clean Air Act 1990 version 1997 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

PREVENTING AND REDUCING AIR POLLUTION
The Clean Air Acts in the United States have greatly reduced outdoor air pollution from six major pollutants: Carbon monoxide Nitrogen oxides Sulfur dioxides Suspended particulate matter (less than PM-10) Tropospheric Ozone

Laws and Regulations Can Reduce Outdoor Air Pollution (2)
Good news in U.S. Decrease in emissions Use of low-sulfur diesel fuel Cuts pollution Developing countries More air pollution

Case Study: U.S. Air Pollution Can Be Improved
Rely on cleanup more than prevention of pollution Raise fuel-efficiency for cars, SUVs, and light trucks Better regulation of emissions of motorcycles and two-cycle gasoline engines Regulate air pollution for oceangoing ships in American ports

Case Study: U.S. Air Pollution Can Be Improved (2)
Why are airports exempt from many regulations? Regulate greenhouse gas emissions Ultrafine particles are not regulated Urban O3 levels too high

Case Study: U.S. Air Pollution Can Be Improved (3)
What about indoor air pollution? Better enforcement of the Clean Air Acts Intense pressure needed from citizens to make improvements

We Can Use the Marketplace to Reduce Outdoor Air Pollution
Emission trading or cap-and-trade program Mixed reactions to program SO2 emissions down significantly NO2 will be tried in the future

There Are Many Ways to Reduce Outdoor Air Pollution
1980 –2006 SO2 emissions from U.S. electric power plants decreased by 66% NOx emissions by 41% Particulate emissions by 28% Older plants not governed by the same regulations New cars have better emissions

Solutions: Stationary Source Air Pollution

Prevention of Air pollution
Post combustion method Catalytic converter to oxidize the sulfur to yield sulfur compounds. A lime scrubber in a smokestack may be used In a wet scrubber, a slurry of lime mixed w/ water is sprayed across the exiting gases. The sulfur mixes w/ the calcium, forming the calcium sulfate, which falls to the bottom of the smokestack as bottom ash. Most particulates are removed post combustion

Electrostatic Precipitator
Cleaned gas Electrodes Four commonly used output or control methods for removing particulates and SO2 from the exhaust gases of electrical power plants. All of these methods produce hazardous materials that must be disposed of safely, and except for cyclone separators, all of them are expensive. Electrostatic precipitators remove 99 percent of the particulates in coal emissions. They function by passing the coal emissions past a series of charged plates, thus charging the particulates, which then bind to an oppositely charged plate. Dust discharge Dirty gas Electrostatic Precipitator

Bags Cleaned gas Dirty gas Baghouse Filter Dust discharge
Bag filters are a series if bags, somewhat like a bag in a vacuum cleaner, which catch the particulates as they rise in the smoke. The bags are periodically emptied of their ash. Baghouse Filter Dust discharge

Cleaned gas Dirty gas Cyclone Separator Dust discharge
Cyclone collectors create a vortex in a smokestack, causing the particles to collide and fall to the bottom of the stack as bottom ash. Cyclone Separator Dust discharge

Dirty gas Cleaned gas Clean water Wet gas Wet Scrubber Dirty water
Modern wet scrubbers remove 98% of the SO2 and 98% of the particulate matter in smokestack emissions, but they are expensive to install and maintain. Wet Scrubber Dirty water

Solutions: Motor Vehicle Air Pollution, Prevention and Cleanup

Reducing Indoor Air Pollution Should Be a Priority
Greater threat to human health than outdoor pollution What can be done? Prevention Cleanup

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

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

Solutions: Indoor Pollution, Prevention and Cleanup or Dilution

What Can You Do? Indoor Pollution: Ways to Reduce Your Exposure

Solutions: Air Pollution, Ways to Prevent It Over the Next 30–40 Years

ABC Video: Clean Air Act

Air Pollution Chapter 18.

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Air Pollution Chapter 18.

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Presentation on theme: "Air Pollution Chapter 18."— Presentation transcript:

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About project

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