learning set 3 - air quality unit

8/14/2019 Learning Set 3 - Air Quality Unit

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What is the Quality of Air in Our Community? Learning Set 3 - Page 65

LEARNINGS

ET3:

WHATDOESPOLLU

TEDAIR

O O

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LEARNING SET 3:

WHAT DOES POLLUTED AIR LOOK LIKE?

CONTENTSOverview and General Information Page 67

Science Understanding for Teachers Page 68

Lesson 10: What Are Pollutants and How Did They Get in the Air? Page 84

Lesson 11: What Do Pollutants Look Like? Page 87

Lesson 12: Investigating Pollutants Page 89

Investigation A - Particulate Matter Investigation (over time) Investigation B - Ozone Detection

Investigation C - Sulfur and Nitrogen Oxides and Acid Rain Investigation D - Particulate Matter from Combustion Engines



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LEARNING SET 3

OVERVIEW AND GENERAL RESOURCES

OverviewNow that students have a good understanding of what air is and what the components of air are,

students are going to explore the notion of air quality, and look at a variety of indicators of air

quality. Students will begin with an online investigation of a number of known air pollutants, using a

jigsaw activity to share basic research findings with each other to get a better understanding of the

different pollutants that can adversely affect air quality. Students revisit models and concept maps

illustrating their ideas about pollutants and their effect on air and air quality. Finally, they engage in

a number of investigations of different pollutants to determine the level of pollutant and air quality

in their school and community.

ResourcesThis learning set requires a number of resources for the investigations that students conduct during

these lessons. First, lesson 10 involves the use of the Internet as a research tool for students to

gather information about a particular pollutant. This lesson assumes the students have access to

computers for searching online information, and access to search engines and pages identified

through those searches. Additionally, it is recommended that students have access to a word

processor for notes taken during the internet research effort, and that they have access to a local or

network folder for storage of these notes.

This learning set also focuses on student designed and implemented investigations of various

pollutants that affect air quality. In particular, we are using the How Clean is the Air? kit from

The Science Source, which can be purchased directly from the producer, or through third-party

science suppliers, such as Carolina or Fisher. Alternately, teachers should review the items in lesson

12 investigations, which may be available from the schools stock supply. Also, Investigation B uses

the EcoBadge kit from Vistanomics, which measures ozone levels in ambient air.

A list of resource items from other teachers and project leaders is available on the Investigate the

State website (http://investigatethestate.org)

http://investigatethestate.org/http://investigatethestate.org/http://investigatethestate.org/


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SCIENCE UNDERSTANDING FOR

TEACHERS

The Clean Air Act and the Environmental Protection Agency

In response to growing scientific evidence concerning the ill effects of various air pollutants, the US

government passed the Clean Air Act if 1970. To enforce this act, the government also established

the Environmental Protection Agency (EPA) in the same year. The Clean Air Act required that air

quality standards be set up in order to protect the people most sensitive to polluted air, such as the

elderly, children, and people with medical conditions such as asthma. National Ambient Air Quality

Standards (NAAQS) were developed for common, widespread pollutants, which had been shown to be

dangerous to the public. These Standards are routinely evaluated and upgraded. The pollutants that

are regulated and monitored are termed criteria pollutants. The table below summarizes some of

these, and the following pages address details about each of the major airborne pollutants. These

pages are also formatted so that you can use them as a handout if needed.

Criteria Pollutant Description Major Sources Major Effects

Carbon Monoxide (CO) Colorless, odorless gas Burning of gasoline bycars Headaches,drowsiness, heart

damage

Sulfur Dioxide (SO2) Gas Coal burning factories

and power plants

Source of acid rain, eye

irritation, breathing

problems

Nitrogen Oxides (NOx) Gas Vehicle exhaust,

burning of fossil fuels

Source of acid rain,

component for ozone

formation, lung damage

Particulate Matter (PM) Small particles of soot,

dust, and ash

Diesel engines, burning

of fossil fuels,volcanoes, forest fires

Lung damage, eye

irritation, discoloring ofbuildings, causes

colorful red sunsets

Ozone (O3) Gas Formed by other air

pollutants in the

presence of sunlight

Smog, lung damage,

eye irritation, source of

acid rain

Lead (Pb) Metal element Leaded gasoline, metal

refineries, burning of

fossil fuels

Brain and kidney

damage, contaminates

crops and livestock

Chlorofluorocarbons

(CFCs)

Group of chemicals

containing Chlorine,Fluorine, and Carbon

Aerosol propellant and

refrigerator coolant

Destroys high level

ozone

Carbon Dioxide (CO2) Colorless, odorless gas Vehicle exhaust,

burning of fossil fuels

Global warming

Acid Rain Rain with pH less than

5.6

Nitrogen Dioxide, Sulfur

Oxides, Ground level

ozone

Damage to buildings,

plant damage, damage

to aquatic life



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Primary and Secondary Pollutants

When a pollutant is released directly in the air it is called a primary pollutant. When cars burn

gasoline, they release three primary pollutants: carbon dioxide, carbon monoxide, and nitrogen

dioxide. The primary pollutants listed above include the following criteria pollutants:

Carbon Monoxide Lead Particulate Matter Sulfur Dioxide Chlorofluorocarbons Nitrogen Oxides Other Toxins

When a pollutant is released into the air, it undergoes a chemical reaction that makes another

pollutant; this newly formed pollutant is called a secondary pollutant. For example, when nitrogen

dioxide (a primary pollutant) is released into the air, it reacts with sunlight and other pollutants in

the air to form ground level ozone. Ground level ozone is a secondary pollutant.

Some common secondary pollutants include:

Ground level ozone Acid rain

Ozone: The good and the bad

Depending upon where ozone is located it is either a substance that is beneficial or harmful to the

atmosphere. Ground level ozone is considered a pollutant. Ozone high in the atmosphere

(stratospheric ozone) is what shields the earth from harmful radiation. When people talk about the

hole in the ozone layer they are referring to stratospheric ozone. When the news issues an ozone

alert or talks about photochemical smog they are talking about ground level ozone. The ozone is a

necessary protective layer in the atmosphere that protects us from the harmful effects of the suns

ultra violet rays. This natural stratospheric ozone layer accounts for about 90% of all ozone gas. The

other 10% is bad ozone, which comes from sources such as car exhaust and air conditioners. The

bad ozone is located down near the earths surface where it can get trapped in air pockets and

cause smog in urban areas. When bad ozone levels are high it prevents people with breathing

problems from going outside and increases the rate of sunburn in all people.

Acid rain is rain, snow or fog that is polluted by acid in the atmosphere and damages the

environment. Two common air pollutants acidify rain: sulphur dioxide (SO2) and nitrogen oxide

(NO2). When the substances are released into the atmosphere, they can be carried over long

distances by prevailing winds before returning to earth as acidic rain, snow, fog or dust. When the

environment cannot neutralize the acid being deposited, damage occurs.



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Pollutant: Carbon Monoxide

Pollutant Name and PropertiesCarbon Monoxide (CO) is a colorless, odorless, tasteless, poisonous gas. Although it has no odor

itself, it is often mixed with other gases that may have an odor. The result is that CO is difficult to

detect and can be inhaled with other gases without an individuals knowledge.

Pollutant Chemical Formula and StructureCarbon Monoxide has a chemical formula of CO, and one carbon and one oxygen atom that share a

triple bond. [ C=O ] This deadly gas is produced by the incomplete burning of various fuels. Any

material containing carbon, when burned, will increase the level of CO.

Pollutant Testing and Air Level StandardsCO concentration is measured in parts per million (ppm). The Occupational Safety and Health

Administration (OSHA) sets a standard of 50 ppm averaged over the length of exposure. According to

the US Consumer Product Safety Commission (CPSC Document #466) most people will not

experience any symptoms from prolonged exposure to CO levels of approximately 1 to 70 ppm, with

the possible exception of some heart patients. If CO levels increase and remain above 70 ppm,

symptoms increase. Initially, these symptoms may include nausea, headache, fatigue, shortness of

breath and dizziness. Higher levels result in increasingly more severe symptoms including mental

confusion, vomiting, loss of muscular coordination, loss of consciousness and death.

How Pollutant is Produced

Some examples of ways in which this gas is produced include the burning of natural gas, gasoline,kerosene, oil, propane, coal, or wood. One of the most common sources of CO is the internal

combustion engine. The products and equipment that use this type of engine (power washers, cars,

lawn mowers, and portable generators) will produce CO. Natural sources of carbon monoxide include

emissions from vegetation and the worlds oceans.

How Pollutant is RemediatedRecommendations from the CDC, EPA, and other organizations suggest the best method of

decreasing the production of and harm from CO is by keeping all combustion applications in proper

working order. Water Heaters, furnaces, fireplaces, chimneys, generators and any other home

appliances operated with a combustion source should be checked yearly. Proper ventilation is key.

Another means by which the risk of exposure can be minimized, or altogether eliminated, is by using

an oxidation catalyst, which will convert harmful Carbon Monoxide, to the much less harmful Carbon

Dioxide. These catalysts are mainly used by industry and can be utilized in enclosed workspaces or in

portable, individual units. The Carbon Monoxide catalyst reaction is CO + O2 = CO2. In the home,

carbon monoxide detectors should be used as a warning measure for the prevention of CO poisoning.



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Problems Associated with this PollutantThe CO level and length of exposure, as well as pre-existing health conditions, will determine the

health effects of CO poisoning. The health conditions above are caused by breathing CO. It is harmful

because it displaces oxygen in the blood and deprives vital organs of the oxygen needed for

functioning. Individuals most susceptible include young children, elderly people, people with lung or

heart disease, people at high altitudes, smokers and fetuses. If caught in time, the poisoning can be

reversed. However, sudden high exposure, or that which is prolonged, may lead to permanent

damage to organs that require high levels of oxygen such as the heart and brain. Carbon Monoxide is

especially dangerous in enclosed spaces. Beyond vehicles, contributors include malfunctioning or

improperly vented fuel-burning appliances such as water heaters, furnaces, ranges, room heaters,

portable generators, and fireplaces.

Although CO is a minor direct greenhouse gas, it has significant indirect effects on global warming.

Because CO reacts with hydroxyl (OH) radicals in the atmosphere, OH is reduced. Hydroxyl radicals

help decrease the lifetimes of major greenhouse gases like methane. Therefore, as the amount of

OH decreases, the global warming potential for these major greenhouse gases is increased.

Sources and Resources http://www.cpsc.gov/cpscpub/pubs/466.html http://www.osha.gov/OshDoc/data_General_Facts/carbonmonoxide-factsheet.pdf http://www.coheadquarters.com/CO1.htm

(Go about 2/3 of the way down to Answering Your Questions) http://www.ghgonline.org/otherco.htm http://ezinearticles.com/?Carbon-Monoxide-Removal&id=1168196

http://ezinearticles.com/?Carbon-Monoxide-Removal&id=1168196http://www.ghgonline.org/otherco.htmhttp://ezinearticles.com/?Carbon-Monoxide-Removal&id=1168196http://ezinearticles.com/?Carbon-Monoxide-Removal&id=1168196http://www.ghgonline.org/otherco.htmhttp://www.ghgonline.org/otherco.htmhttp://www.coheadquarters.com/CO1.htmhttp://www.coheadquarters.com/CO1.htmhttp://www.osha.gov/OshDoc/data_General_Facts/carbonmonoxide-factsheet.pdfhttp://www.osha.gov/OshDoc/data_General_Facts/carbonmonoxide-factsheet.pdfhttp://www.cpsc.gov/cpscpub/pubs/466.htmlhttp://www.cpsc.gov/cpscpub/pubs/466.html


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Pollutant: Carbon Dioxide

Pollutant Name and PropertiesCarbon Dioxide (CO) is emitted both naturally through the carbon cycle, and through a variety of

human activities including the burning of fossil fuels. CO is colorless, odorless, slightly acidic, and

non-flammable. It makes up 0.0314% of air, but is also found in water as part of the carbon cycle.

Although CO is generally a gas, it can become a liquid and water soluble when kept under pressure.

It becomes a solid at temperatures below -78C.

Pollutant Chemical Formula and StructureCarbon Dioxide has a chemical formula of CO, and consists of a carbon atom that shares a double

bond with two oxygen atoms. [O=C=O] This gas is vital to all life on earth. The process of plant

photosynthesis entails CO from the atmosphere being stored as carbon in plant biomass. Conversely,

oxygen and nutrients are converted into CO and energy through the process of respiration.

Pollutant Testing and Air Level StandardsGreenhouse gases, of which CO is a main component, are necessary for sustaining life on earth. It is

these gases regulation of temperature, within the troposphere, that maintain a climate warm

enough for life as we know it to exist. Since the Industrial Revolution began in 1850 greenhouse

gases have grown so extensively that climate is changing because temperatures are rising. Carbon

Dioxide emissions cause approximately 50 - 60% of global warming. These emissions rose from 280

ppm in 1850 to 364 ppm in the late 1990s. CO remains in the troposphere between 50 and 200

years.

How Pollutant is ProducedWithin the carbon cycle, billions of tons of CO are removed from the atmosphere by terrestrial

vegetation and oceans. These are known as sinks. CO is emitted back into the atmosphere each

year through natural processes such as respiration, also called sources. When balanced, these

processes lead to a roughly equal number of emissions and removals. Since the Industrial Revolution,

human activity has led to a 35% increase in the atmospheric levels of CO. This has occurred mainly

through deforestation and the burning of coal, gas and oil.

The greatest contributor of Carbon Dioxide emissions from human activity is the combustion of fossil

fuels. These represented 81% of the total U.S. greenhouse gas emissions in 2007. In the United States

the generation of electricity using natural gas, petroleum and coal is the greatest source of CO

emissions. These processes account for 41% of all CO emissions in our country. Transportation is the

second largest source of CO emissions in the U.S. and almost all of that is petroleum based. Industry

is another contributor with activities such as manufacturing, construction and mining. Within

manufacturing, petroleum refining, chemical production, metal production, paper, food, and

mineral production account for the majority of energy use and CO emissions. Commercial and



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residential energy usage also contribute a significant amount of CO due to their reliance on

electricity for meeting their energy needs, especially the heating and cooling of buildings.

Globally, deforestation is a significant contributor of CO emissions when not counter-balanced by

new tree growth. When trees are permanently removed, the carbon sequestered there is released

through either burning or gradual decomposition over time.

How Pollutant is RemediatedGeologic sequestration (GS) is a technology that is gaining increased use for stationary sources of

CO emissions. In this process, CO is captured and injected underground for long-term storage.

Because CO created through natural processes has been held in geologic formations for hundreds of

millions of years, there is growing confidence in these methods of reducing CO emissions.

Problems Associated with this PollutantCarbon Dioxide is essential to human health in the process of internal respiration where oxygen is

carried to bodily tissues and CO is carried away. Carbon Dioxide is also an essential buffer

(carbonate buffer) in the human system as it is the means by which the pH of blood is maintained at

the necessary level for survival. An increase or decrease in pH is life threatening. The primary

dangers of CO to human health are: asphyxiation (from CO release in a confined or unventilated

space), frostbite (from handling dry ice or contact with the gas released from a steel cylinder - e.g.

fire extinguisher), and kidney damage and coma (when the carbonate buffers equilibrium is

disturbed by an increase or decrease in CO).

Sources and Resources http://www.epa.gov/climatechange/emissions/co2.html

http://www.epa.gov/climatechange/emissions/co2_natural.html http://www.epa.gov/climatechange/emissions/co2_human.html http://www.lenntech.com/carbon-dioxide.htm http://tonto.eia.doe.gov/energyexplained/index.cfm?

page=environment_where_ghg_come_from

http://tonto.eia.doe.gov/energyexplained/index.cfm?page=environment_where_ghg_come_fromhttp://tonto.eia.doe.gov/energyexplained/index.cfm?page=environment_where_ghg_come_fromhttp://tonto.eia.doe.gov/energyexplained/index.cfm?page=environment_where_ghg_come_fromhttp://tonto.eia.doe.gov/energyexplained/index.cfm?page=environment_where_ghg_come_fromhttp://www.epa.gov/climatechange/emissions/co2_human.htmlhttp://www.epa.gov/climatechange/emissions/co2_natural.htmlhttp://tonto.eia.doe.gov/energyexplained/index.cfm?page=environment_where_ghg_come_fromhttp://tonto.eia.doe.gov/energyexplained/index.cfm?page=environment_where_ghg_come_fromhttp://tonto.eia.doe.gov/energyexplained/index.cfm?page=environment_where_ghg_come_fromhttp://tonto.eia.doe.gov/energyexplained/index.cfm?page=environment_where_ghg_come_fromhttp://www.lenntech.com/carbon-dioxide.htmhttp://www.lenntech.com/carbon-dioxide.htmhttp://www.epa.gov/climatechange/emissions/co2_human.htmlhttp://www.epa.gov/climatechange/emissions/co2_human.htmlhttp://www.epa.gov/climatechange/emissions/co2_natural.htmlhttp://www.epa.gov/climatechange/emissions/co2_natural.htmlhttp://www.epa.gov/climatechange/emissions/co2.htmlhttp://www.epa.gov/climatechange/emissions/co2.html


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Pollutant: Sulfur Oxides

Pollutant Name and PropertiesSulfur Dioxide (SO) is the most prevalent of the Sulfur Oxides (SOx). Sulfur Trioxide (SO3) is another

oxide of sulfur that is significant to air quality. SO is a dense, colorless, non-flammable, toxic gas

with a strong odor. It is a liquid under pressure and dissolves easily in water. SO3 , at normal

temperatures and pressures, is a liquid that is highly reactive and due to its abundance of oxygen,

combines with many substances.

Pollutant Chemical Formula and StructureSulfur Dioxide has a chemical formula of SO, and consists of a sulfur atom that shares a double bond

with two oxygen atoms. [O=S=O] Sulfur Trioxides molecule has a double bond with all three of

OII

its oxygen atoms. [O=S=O] Both of these molecules are considered resonance hybrids with one of the

bonds actually fluctuating between a single and double bond.

Pollutant Testing and Air Level StandardsThe EPA has set an air quality standard of 0.03 ppm for long-term exposure averaged per year. Short-

term standards state that 24-hour air concentrations should not exceed 0.14 ppm more than once a

year. OSHA has set a limit of 2 ppm over an eight hour work day. The three types of SOx monitoring

systems used in industrial applications are continuous stack monitoring, spot sampling, and surrogate

monitoring. Continuous stack monitoring (CSM) involves sophisticated equipment that requires

trained operators and careful maintenance. Spot sampling is performed by drawing gas samples from

the stack at regular intervals. Surrogate monitoring uses operating parameters such as fuel sulfur

content.

How Pollutant is ProducedNatural sources of SO emissions include volcanoes, the oceans, biological decay, and forest fires.

These account for 35 - 65% of total sulfur dioxide emissions. Human generated sources of sulfur

oxides include electricity generation, fossil fuel combustion, industrial processes, non-road

equipment and vehicles. Of the human generated sulfur oxides, 75 - 80% are from fossil fuel

combustion. Thermal power plants burn high-sulfur coal or heating oil. These are the main source of

sulfur dioxide emissions worldwide. The next biggest sources are industrial boilers and nonferrous

metal smelters. Locally, emissions from vehicles and domestic coal burning contribute to high levelsof SO. It is estimated that natural sources release between 80 and 290 million tons of sulfur oxides

into the atmosphere each year. Another 70 to 100 tons is contributed annually by humans, with

approximately 20 tons of that total contributed by the United States.



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HowPollutant is RemediatedA variety of methods have been developed to remediate SOx in the industrial setting. One method is

to use a hydrocarbon to stimulate the growth of hydrocarbons utilizing bacteria. A second method

involves emission control technologies such as dry sorbent injection and flue gas desulfurization

(FGD) through wet scrubbing. Sorbent injection involves the introduction of dry sorbents such as

lime or limestone which, when reacting with SO2 in flue gases, forms solid calcium sulfate which can

then be removed and disposed of. Wet scrubbing occurs when flue gases are accelerated through a

nozzle, saturated with a scrubbing liquid that has been injected with sodium hydroxide (NaOH) and

after contact with SO2 is converted to sodium sulfate (Na2SO4). The sodium sulfate is then removed

from the liquid. Other changes that will help control sulfur oxides in the environment include

choosing fuels with a low sulfur content (natural gas) and the use of appropriate combustion

technologies.

Problems Associated with this PollutantThe health effects of SO are primarily linked to the respiratory system. As with NO, the severity is

dependent on length of exposure and underlying health conditions which may make some individualsmore susceptible. Some of the health effects associated with SO include irritation of the eyes, nose,

and throat, impaired lung function, and increased respiratory symptoms and diseases. Very high-

dose exposure to SO may cause most of the health problems associated with the sulfur oxides and

can even be life-threatening. The symptoms include burning of the nose and throat, breathing

difficulties, and severe airway obstruction. Lower, but consistent levels, over time, have been found

to also impair health. For those who have asthma, or other chronic respiratory difficulties, even low

level SO exposure may cause increased inflammation of the airways and decreased lung function. In

the atmosphere, sulfur oxides can combine with other compounds to form small particles. This

particulate matter can, in turn, penetrate the lungs and cause or worsen respiratory disease.

Sulfur oxidesare not considered a greenhouse gas, but instead they are criteria pollutants. These are

man-made pollutants that have an indirect effect on global warming. Sulfur Oxides are a large factor

in the production of acid rain. The process involves SO oxidizing to SO3. Sulfur Trioxide then

combines with water vapor or droplets to form sulfuric acid (H2SO4). Sulfuric acid is one of the acids

that make up acid rain. Acid depositions of this type are harmful to vegetation, freshwater lake and

stream ecosystems, and stone and metals in building structures.

Sources and Resources

http://www.epa.gov/air/sulfurdioxide/ http://www.windows.ucar.edu/tour/link=/physical_science/chemistry/

sulfur_oxides.html&edu=high&portal=cmmap http://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.html http://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_SulfurOxides/$FILE/

HandbookSulfurOxides.pdf http://www.atsdr.cdc.gov/tfacts116.html http://www.cleanairtrust.org/sulfurdioxide.html http://www.crwi.org/textfiles/so2.htm http://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_pguiSulfurOxides/$FILE/

HandbookSulfurOxidesPollutionPreventionAndControl.pdf

http://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_pguiSulfurOxides/$FILE/HandbookSulfurOxidesPollutionPreventionAndControl.pdfhttp://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_pguiSulfurOxides/$FILE/HandbookSulfurOxidesPollutionPreventionAndControl.pdfhttp://www.crwi.org/textfiles/so2.htmhttp://www.atsdr.cdc.gov/tfacts116.htmlhttp://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_SulfurOxides/$FILE/HandbookSulfurOxides.pdfhttp://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.htmlhttp://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.htmlhttp://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.htmlhttp://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.html&edu=high&portal=cmmaphttp://www.epa.gov/air/sulfurdioxide/http://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_pguiSulfurOxides/$FILE/HandbookSulfurOxidesPollutionPreventionAndControl.pdfhttp://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_pguiSulfurOxides/$FILE/HandbookSulfurOxidesPollutionPreventionAndControl.pdfhttp://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_pguiSulfurOxides/$FILE/HandbookSulfurOxidesPollutionPreventionAndControl.pdfhttp://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_pguiSulfurOxides/$FILE/HandbookSulfurOxidesPollutionPreventionAndControl.pdfhttp://www.crwi.org/textfiles/so2.htmhttp://www.crwi.org/textfiles/so2.htmhttp://www.cleanairtrust.org/sulfurdioxide.htmlhttp://www.cleanairtrust.org/sulfurdioxide.htmlhttp://www.atsdr.cdc.gov/tfacts116.htmlhttp://www.atsdr.cdc.gov/tfacts116.htmlhttp://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_SulfurOxides/$FILE/HandbookSulfurOxides.pdfhttp://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_SulfurOxides/$FILE/HandbookSulfurOxides.pdfhttp://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_SulfurOxides/$FILE/HandbookSulfurOxides.pdfhttp://www.ifc.org/ifcext/enviro.nsf/AttachmentsByTitle/p_ppah_SulfurOxides/$FILE/HandbookSulfurOxides.pdfhttp://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.htmlhttp://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.htmlhttp://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.html&edu=high&portal=cmmaphttp://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.html&edu=high&portal=cmmaphttp://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.html&edu=high&portal=cmmaphttp://www.windows.ucar.edu/tour/link=/physical_science/chemistry/sulfur_oxides.html&edu=high&portal=cmmaphttp://www.epa.gov/air/sulfurdioxide/http://www.epa.gov/air/sulfurdioxide/


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Problems Associated with this PollutantThe health effects of NO are dependent on length of exposure and underlying health conditions

which may make some individuals more susceptible. Some of the health effects associated with NO

include eye, nose, and throat irritation and possibly impaired lung function and increased respiratory

infections in young children. High-dose exposure, as may occur in a building fire, may lead to fluid

retention in the lungs and widespread lung injury. If exposure to high NO levels is continuous, it

may lead to acute or chronic bronchitis. For those who have asthma, chronic obstructive pulmonary

disease (COPD), or an increased risk of respiratory infection, even low level NO exposure may cause

increased bronchial reactions and decreased lung function.

In the atmosphere, nitrogen oxides can contribute to the formation of photochemical ozone (smog).

Nitrogen oxidesare also very important in the formation andloss of tropospheric ozone. They

continuously react and reform through catalytic cycles. Nitrogen dioxide (NO2) is broken down by

sunlight to form nitrogen monoxide (NO). This NO then re-reacts to form more NO2. Nitrogen oxides

also lead to acid rain and contribute to global warming. Nitrogen oxides react with water to form

nitric acid (HNO3).

Nitric acid is not only a major contributor to acid rain but is also the main way inwhich nitrogen oxides are removed from the air.

Sources and Resources http://www.epa.gov/air/nitrogenoxides/ http://www.epa.gov/air/emissions/nox.htm http://www.epa.gov/iaq/no2.html http://www.apis.ac.uk/overview/pollutants/overview_NOx.htm http://www.greenfacts.org/en/nitrogen-dioxide-no2/index.htm http://www.atmosphere.mpg.de/enid/23b.html

http://www.atmosphere.mpg.de/enid/23b.htmlhttp://www.greenfacts.org/en/nitrogen-dioxide-no2/index.htmhttp://www.apis.ac.uk/overview/pollutants/overview_NOx.htmhttp://www.epa.gov/iaq/no2.htmlhttp://www.epa.gov/air/emissions/nox.htmhttp://www.epa.gov/air/nitrogenoxides/http://www.atmosphere.mpg.de/enid/23b.htmlhttp://www.atmosphere.mpg.de/enid/23b.htmlhttp://www.greenfacts.org/en/nitrogen-dioxide-no2/index.htmhttp://www.greenfacts.org/en/nitrogen-dioxide-no2/index.htmhttp://www.apis.ac.uk/overview/pollutants/overview_NOx.htmhttp://www.apis.ac.uk/overview/pollutants/overview_NOx.htmhttp://www.epa.gov/iaq/no2.htmlhttp://www.epa.gov/iaq/no2.htmlhttp://www.epa.gov/air/emissions/nox.htmhttp://www.epa.gov/air/emissions/nox.htmhttp://www.epa.gov/air/nitrogenoxides/http://www.epa.gov/air/nitrogenoxides/


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Pollutant: Ozone

Pollutant Name and PropertiesGround-Level Ozone is also known as bad ozone. At this layer of the atmosphere, the troposphere,

it is an air pollutant. It is harmful to health and the environment. At higher levels, the stratospheric

ozone, or good ozone, protects the earth from the suns harmful ultra-violet (UV) rays.

Pollutant Chemical Formula and StructureOzone (O3) is a gas composed of three oxygen atoms. It has the same chemical make-up in the

stratosphere as it does in the ground-level troposphere. The structure is a resonant one with the

double and single bond between oxygens being shared equally as shorter, stronger bonds. It is

written [O-O=O] [O=O-O].

Pollutant Testing and Air Level StandardsThe EPA has set standards for ozone to protect health and the environment. The current standard is

an 8 hour average of no more than 0.075 parts per million (ppm). This standard was set at that level

in March of 2008. Prior to that time, since 1997, the standard was set at 0.084 ppm for 8 an hour

average. On September 16, 2009, EPA announced the reconsideration of the 2008 ozone

standard. The agency will propose any revisions to the ozone standard by December 2009

and will issue a final decision by August 2010. (EPA)

How Pollutant is ProducedOzone occurs naturally in the stratosphere, but at ground-level is created, in the presence of

sunlight, by a chemical reaction between oxides of nitrogen (NOx) and volatile organic compounds

(VOC). Some of the major sources of NOx and VOC include chemical solvents, gasoline vapors,

emissions from industrial facilities and electric utilities, and motor vehicle exhaust. Hot weather and

sunlight cause ground-level ozone to form in harmful concentrations in the air and become a primary

component of smog.

How Pollutant is RemediatedCurrently, there is no process by which ozone can be directly removed from ground-level air.

However, because of the Clean Air Act, programs are being put into place to cut NOx and VOC

emissions from vehicles, industrial facilities, and electric utilities across the nation. Additional

means of reducing these pollutants are through programs that lead to the reformulation of fuels and

consumer/commercial products, such as paints and chemical solvents, that contain VOC. The

practice of carpooling is another measure that communities may encourage to reduce these harmful

emissions.



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Problems Associated with this PollutantThe health effects associated with ground-level ozone include coughing, congestion, throat irritation

and chest pain. Individuals with respiratory conditions such as emphysema, bronchitis, and asthma

may experience increased difficulties. Those who healthy and active outdoors, are also likely to

experience the effects of ozone on their respiratory health. Ground-level ozone can inflame thelining of the lungs and lead to reduced lung function. Being repeatedly exposed to ground-level

ozone over time may permanently scar lung tissue.

Ground-level ozone also has a negative impact on vegetation and ecosystems. Some of these effects

include decreasing the function of sensitive plants by decreasing their ability to produce and store

food, and making them more susceptible to other pollutants, insects, competition, certain diseases

and other environmental stresses. Ozone can also damage the leaves of plants and trees leading to a

reduction in forest growth and crop yields. In a meta-analysis of 52 studies of wheat, Feng et al.

(2008) reported that current ambient O3 concentrations may be decreasing yield by an average of

17.5%. In addition, the damage to vegetation may negatively impact the diversity of species inecosystems.

Sources and Resources http://www.epa.gov/air/ozonepollution/basic.html http://www.epa.gov/air/ozonepollution/health.html http://www.epa.gov/air/emissions/voc.html http://www.epa.gov/air/oaqps/gooduphigh/ http://scifun.chem.wisc.edu/CHEMWEEK/Ozone/ozone.html http://www.airnow.gov/

Feng ZZ, Kobayashi K, Ainsworth EA. Impact of elevated ozone concentration on growth, physiology, and yieldof wheat (Triticum aestivum L.): a meta-analysis. Global Change Biology. 2009; 14(11): 2696-2708.

http://scifun.chem.wisc.edu/CHEMWEEK/Ozone/ozone.htmlhttp://www.epa.gov/air/oaqps/gooduphigh/http://www.epa.gov/air/emissions/voc.htmlhttp://www.epa.gov/air/ozonepollution/health.htmlhttp://www.epa.gov/air/ozonepollution/basic.htmlhttp://www.airnow.gov/http://www.airnow.gov/http://scifun.chem.wisc.edu/CHEMWEEK/Ozone/ozone.htmlhttp://scifun.chem.wisc.edu/CHEMWEEK/Ozone/ozone.htmlhttp://www.epa.gov/air/oaqps/gooduphigh/http://www.epa.gov/air/oaqps/gooduphigh/http://www.epa.gov/air/emissions/voc.htmlhttp://www.epa.gov/air/emissions/voc.htmlhttp://www.epa.gov/air/ozonepollution/health.htmlhttp://www.epa.gov/air/ozonepollution/health.htmlhttp://www.epa.gov/air/ozonepollution/basic.htmlhttp://www.epa.gov/air/ozonepollution/basic.html


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Pollutant: Particulate Matter

Pollutant Name and PropertiesParticulate Matter (PM) is also known as particle pollution. PMs properties are classified by their

diameter, also called particle size. Coarse particles are measured between 2.5 micrometers and 10

micrometers. Fine particles measure 2.5 micrometers or smaller. (The average diameter of a single

human hair is approximately 70 micrometers.) The size of particles also determines how long they

remain in the air. Precipitation and sedimentation removes coarse PM from the atmosphere within a

few hours, while fine PM may remain in the air for days or weeks. Therefore, these fine particles

may be transported over great distances. Particles are further classified asprimaryor secondary.

Primary particles are emitted directly into the air by man-made and natural processes from a

particular source. These include combustion from vehicles, the burning of solid fuel, industrial

activity, household combustion, and fires. Secondary sources create most of the fine particle

pollution in the United States, and develop in the air through chemical reactions of gaseous

pollutants.

Pollutant Chemical Formula and StructureParticulate Matter, PM, is a mixture of airborne liquid droplets and solid particles made up of a

complex combination of organic and inorganic substances. These particles can be made up of

hundreds of different chemicals and occur in many sizes and shapes. Some particles are large or dark

enough to be seen with the naked eye (e.g. smoke, soot, dust, and dirt). Other particles can be so

small, that an electron microscope is needed to detect them. The coarse particles are referred to as

PM10, while the fine particles are labeled PM2.5. (See first paragraph)

Pollutant Testing and Air Level StandardsTheir are two national air quality standards for particle pollution. The Primary Standards were

developed to set limits that would protect public health including sensitive groups such as

children, the elderly, and asthmatics. Secondary Standards were developed to set limits to protect

the public against such hazards as visibility impairment, and damage to crops, vegetation, buildings

and animals. The first standards for PM were established in 1971 in the United States. They have

been changed over time with the latest revision occurring in 2006. These standards changed the 24-

hour fine particle standard from 65 micrograms per cubic meter (m3) to 35 micrograms per (m3), and

retained the annual fine particle standard at 15 micrograms per (m3), averaged over three years. The

1997 24-hour standard for PM10 of 150 micrograms per (m3) was retained at that time. The EPA must

review the latest scientific information and standards every five years. It is therefore possible that

standards will once again change in 2011.

How Pollutant is ProducedCourse particle pollution, PM10, is produced from multiple sources such as construction sites, fields,

smokestacks, unpaved roads, fires, combustion from vehicle engines, industrial activities such as

mining, manufacturing and smelting, and the erosion of pavement by traffic. Fine particle pollution,

PM2.5, is most often produced when Nitrogen Oxides, NOx, and Sulfur Dioxide, SO2, are transformed



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in the atmosphere. These pollutants are usually a result of automobile, industry and power plant

emissions.

How Pollutant is RemediatedThe EPA and other agencies world wide are working to set emission standards for PM that will reduce

its incidence and consequently its effects. Some methods that are being developed and/or used

include exhaust filters on vehicles, cleaner burning fuels (especially diesel), and stricter regulationson industrial processes. Through a nationwide network of monitoring sites, the EPA has recorded an

average decrease of PM2.5 between 2000 and 2008 of 19%. (PM2.5 monitoring began in 1999.) The

national average decrease in PM10 between 1990 and 2008 was recorded at 31%.

Problems Associated with this PollutantThe health effects associated with particulate matter are related to a decrease in respiratory and

cardiac functions. Fine particles, PM2.5, are the greatest problem as they are easily inhaled deep into

the lungs and may even be absorbed into the bloodstream. Difficulty breathing, aggravated asthma,

the development of chronic bronchitis, and irritation of the airways are a few of the significant

health problems associated with PMs effects on the lungs. The most significant cardiac effects are

irregular heartbeat and heart attacks. According to the EPA and some European studies, PM can lead

to premature death in people with heart or lung disease. As with other pollutants, children and the

elderly are most susceptible to the effects of particulate matter.

Unlike ground-level ozone which peaks in summer months, particle pollution occurs year-round.

Particulate matter can harm the environment by changing the nutrient and chemical balance when it

settles on soil and water. The effects of this settling include: making lakes and streams acidic;

changing the nutrient balance in coastal waters and large river basins; depleting the nutrients in soil;

damaging sensitive forests and farm crops; and affecting the diversity of ecosystems. Prior to fallingto the earth, sulfur dioxide (SO2) and nitrogen oxide (NOx) gases and their particulate matter

derivativessulfates and nitratescontribute to visibility degradation and harm public health. Fine

particles have been determined to be the major cause of haze (reduced visibility) in parts of the

United States. This reduced visibility affects not only our cities, but also our national parks and

wilderness areas. Particle pollution can stain and damage stone and other materials, including

culturally important objects such as statues and monuments.

Sources and Resources http://www.epa.gov/oar/particlepollution/

http://www.epa.gov/air/emissions/pm.htm http://www.epa.gov/OMS/invntory/overview/pollutants/pm.htm http://www.epa.gov/airtrends/pm.html http://www.arvinmeritor.com/media_room/pdfs/gp0441.pdf http://www.epa.gov/airtrends/pm.html

http://www.epa.gov/airtrends/pm.htmlhttp://www.epa.gov/airtrends/pm.htmlhttp://www.epa.gov/OMS/invntory/overview/pollutants/pm.htmhttp://www.epa.gov/oar/particlepollution/http://www.epa.gov/oar/particlepollution/http://www.epa.gov/oar/particlepollution/http://www.epa.gov/airtrends/pm.htmlhttp://www.epa.gov/airtrends/pm.htmlhttp://www.arvinmeritor.com/media_room/pdfs/gp0441.pdfhttp://www.arvinmeritor.com/media_room/pdfs/gp0441.pdfhttp://www.epa.gov/airtrends/pm.htmlhttp://www.epa.gov/airtrends/pm.htmlhttp://www.epa.gov/OMS/invntory/overview/pollutants/pm.htmhttp://www.epa.gov/OMS/invntory/overview/pollutants/pm.htmhttp://www.epa.gov/air/emissions/pm.htmhttp://www.epa.gov/air/emissions/pm.htmhttp://www.epa.gov/oar/particlepollution/http://www.epa.gov/oar/particlepollution/


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Pollutant: Chlorofluorocarbons (CFCs)

Pollutant Name and PropertiesChlorofluorocarbons (CFCs) are a series of hydrocarbons containing both chlorine and fluorine. CFCs

are nontoxic, nonflammable, but highly volatile compounds. Unlike most pollutants, they do not

break down in the lower atmosphere. At that level, they are inert and safe to use in most instances.

Pollutant Chemical Formula and StructureChemically, CFCs are a subset of the more general class of compounds known as halocarbons

(carbon- and halogen-containing compounds). CFCs are halocarbons that contain carbon and some

combination of fluorine and chlorine atoms. The most common CFCs are small molecules containing

only one or two carbon atoms. For example, a common refrigerant has the chemical formula of

CCl2F2, also known as CFC-12 (Dichlorodifluoromethane). Each kind of CFC has a different

formulation: CFC 11: CCl3F (Trichlorofluoromethane), CFC 113: C2Cl3F3 (Trichlorotrifluoromethane).

These three CFCs are the most harmful of the group. CFCs (11, 12, and 113) are long-lived in the

stratosphere, inflicting damage on ozone for decades. CFC 12 is able to survive in the stratospherefor more than 100 years.

Pollutant Testing and Air Level StandardsThe ban on production and import of Class 1 Ozone Depleting substances (ODS) took effect on

January 1, 1996 as agreed to under the Montreal Protocol. CFCs are a Class 1 ODS.

Hydrochlorofluorocarbons (HCFCs), are less destructive to the ozone and have been used as a

substitute for CFCs since their phaseout. As a Party to the Montreal Protocol, the U.S. must

incrementally decrease HCFC consumption and production, culminating in a complete HCFC phaseout

in 2030. The major milestones that are upcoming for developed countries are a reduction in 2010 to

at least 75 percent below baseline HCFC levels and a reduction in 2015 to at least 90 percent below

baseline. (EPA Regulatory Programs)

How Pollutant is ProducedChlorofluorocarbons are a class of man-made chemicals. They are known by trade names such as

Freon, Genetron, and Isotron. The first patent for the formula of CFCs was granted in 1928 to

the Frigidaire Corporation. CFCs had been developed to replace the toxic gases that were used in

refrigerants in the late 1800s and early 1900s. After World War ll, CFCs were used as propellants for

bug sprays, paints, hair conditioning and health care products. In the 1950s and 1960s the CFCs

provided an inexpensive solution to the desire for air conditioning in homes, cars and offices. CFCshave been used as refrigerants, air-conditioning systems, blowing agents and packing materials,

cleaning fluids, solvents, and fire-extinguishing agents. The growth of CFC use took off worldwide

after the 1960s with peak production of more than one million metric tons of CFCs per year.

CFCs rise slowly through the troposphere taking 6 to 8 years to reach the stratosphere. It is at this

upper level of the atmosphere that CFCs undergo significant reactions. They are decomposed by UV

radiation there and are a major source of inorganic chlorine. The chlorine that CFCs release destroys



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ozone in catalytic reactions. During these reactions, 100,000 molecules of ozone can be destroyed by

each atom of chlorine.

HowPollutant is RemediatedThrough reductions in CFCs, made possible by global agreements, the EPA states that CFCs are no

longer accumulating at an accelerating rate. Some CFC levels are decreasing and others have slowed

in their rate of accumulation. The NOAA site listed below has a nice graph on the last page thatillustrates this leveling off of one particular CFC molecule type. CFCs are stable enough in the

troposphere that remediation is difficult.

According to the EPA, slurrying soils contaminated with CFCs at ambient temperature in CaNH3

solutions should result in near quantitative dehalogenation and halide mineralization in minutes. No

reference was found to indicate if this technology is currently in use.

Problems Associated with this PollutantThe health effects of CFCs are primarily linked to the depletion of stratospheric ozone. A loss of

ozone at this level of the atmosphere results in more harmful UV-B radiation reaching the Earthssurface. Human health is affected by the increased likelihood of developing skin cancer and

cataracts, and depression of the immune system. Another risk to human health involves the use of

inhalants by individuals. High concentrations of CFCs, when inhaled, affect the nervous and

respiratory systems. Symptoms include a reduced ability to concentrate, dizziness, headaches, and

bronchial constriction which may lead to sudden death.

Chlorofluorocarbons pose two major threats to the global environment. The first is the greenhouse

effect, and the second is reduction of the ozone layer. CFCs contribute to the greenhouse effect by

warming the atmosphere and trapping heat which is then radiated back into the atmosphere. CFCs

are 10,000 times more effective at trapping this radiated heat than carbon dioxide. The protectivelayer of ozone in the atmosphere is also depleted by CFCs. As discussed above, this is accomplished

through the release of chlorine and the resulting catalytic reactions. With ozone depletion those

health effects referred to in the above paragraph increase. Increased ultraviolet radiation reaching

the earth also affects plant and animal life. Some of the results from this increase include reduced

crop yields and depletion of marine fisheries. Damage to construction materials and an increase in

smog are additional effects. Because CFCs have been shown to cause stratospheric ozone depletion,

they have been banned for many uses.

Sources and Resources http://www.theozonehole.com/cfc.htm http://www.purdue.edu/envirosoft/housewaste/house/chlorofl.htm http://www.epa.gov/ebtpages/airairpochlorofluorocarbonscfcs.html http://www.esrl.noaa.gov/gmd/hats/publictn/elkins/cfcs.html http://www.pollutionissues.com/Br-Co/CFCs-Chlorofluorocarbons.html http://www.epa.gov/ozone/title6/phaseout/classtwo.html http://www.epa.gov/ozone/title6/phaseout/classone.html

http://www.epa.gov/ozone/title6/phaseout/classone.htmlhttp://www.pollutionissues.com/Br-Co/CFCs-Chlorofluorocarbons.htmlhttp://www.esrl.noaa.gov/gmd/hats/publictn/elkins/cfcs.htmlhttp://www.purdue.edu/envirosoft/housewaste/house/chlorofl.htmhttp://www.theozonehole.com/cfc.htmhttp://www.epa.gov/ozone/title6/phaseout/classone.htmlhttp://www.epa.gov/ozone/title6/phaseout/classone.htmlhttp://www.epa.gov/ozone/title6/phaseout/classtwo.htmlhttp://www.epa.gov/ozone/title6/phaseout/classtwo.htmlhttp://www.pollutionissues.com/Br-Co/CFCs-Chlorofluorocarbons.htmlhttp://www.pollutionissues.com/Br-Co/CFCs-Chlorofluorocarbons.htmlhttp://www.esrl.noaa.gov/gmd/hats/publictn/elkins/cfcs.htmlhttp://www.esrl.noaa.gov/gmd/hats/publictn/elkins/cfcs.htmlhttp://www.epa.gov/ebtpages/airairpochlorofluorocarbonscfcs.htmlhttp://www.epa.gov/ebtpages/airairpochlorofluorocarbonscfcs.htmlhttp://www.purdue.edu/envirosoft/housewaste/house/chlorofl.htmhttp://www.purdue.edu/envirosoft/housewaste/house/chlorofl.htmhttp://www.theozonehole.com/cfc.htmhttp://www.theozonehole.com/cfc.htm


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LESSON 10:

WHAT ARE POLLUTANTS AND HOW DID

THEY GET IN THE AIR?

OVERVIEW AND OBJECTIVES

Learning ObjectivesStudents will learn strategies for using online search engines to conduct research on known air

pollutants. Students will learn proper strategies for focusing on content, evaluating web sites,

documenting sources, and effectively using information from Internet searches to find quality

information for their pollutant presentations (in Lesson 13)

Assessment CriteriaStudents are able to name and identify a particular pollutant that they have been assigned, identify

its sources, health effects, other effects, and possible strategies being considered for remediation of

the issues caused by excessing amounts of the pollutant.

PurposeThis lesson focuses on three separate goals. First, students learn effective strategies for searching

for reference content about scientific concepts or phenomena. If students havent been provided

some specific information about how to use and cite information they find (and avoid plagiarism),

and about how to use custom functionality of a search engine and web browser, these strategies are

provided in this lesson. Second, students will learn about a specific pollutant that affects air

quality, so that they can not only use this information on their own, but can also teach others about

the considerations related to that pollutant. Finally, this lesson, conducted as independent research

by individual students or groups, allows a wide range of content to be addressed through

specialization and sharing techniques among students, thereby making a more efficient use of

instructional time in class.

PREPARATION

Materials: Student Worksheet/Online Investigation of Pollutants

Set-upStudents will need to be assigned to a particular pollutant for this lesson. Because this will later

lead to a hands-on investigation of many of the pollutants listed here, and because students may

have significant prior knowledge (or confidence) in their internet search strategies, it is important to



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remember that the pollutants you assign here will also be used later by the same students, and so

you should consider this when assigning pollutants for study to students.

This lesson also involves a considerable amount of time with students on computers conducting

searches and reviewing content. You will need to make arrangements for students to have computer

access, and should check some of the common web tools to see if searches using common terms

related to the pollutants bring up inappropriate content. Ideally, your school also has a policy /

strategy for students to take notes for later use in creating their presentations and synthesizing

content.

TimeTwo-three fifty-minute periods.

INSTRUCTIONAL SEQUENCE

Introducing the LessonReview the driving question with students. Discuss how they have, to date, discussed a number of

issues related to what is in the air, including the many components of air that have always been

present, and are not considered to be serious health hazards. These include nitrogen gas, oxygen

gas, water vapor, carbon dioxide (in relatively small amounts as occurs naturally) and other trace

gases.

Explain that this lesson, along with the next two, will focus more on the components of air that ARE

harmful, and for the most part, are the product of human activity or efforts.

Ask students to brainstorm items that they know or consider to be airborne pollutants. Write items

from the list, so that they can be reviewed later. Ask the students, How do they know these items

are pollutants? Tell students that you are going to create a list of considerations that relate to allpollutants. Ask students to now brainstorm a list of qualities that they might say about pollutants.

Examples might include that they are not typically present in nature, or that they can cause health

issues in people or other living organisms. While these are not definitive, they will help you identify

possible misconceptions that students may have.

Conducting the LessonInform students that they are going to do some research on what people already know about

pollutants in order to better understand the problems and issues with air quality. Explain that

scientists go through a similar process, often called library research or literature review (even

though more of this now takes place on-line, and the literature mentioned is simply written, peer-

reviewed research findings. When scientists are investigating a particular question, before they try

generating a specific hypothesis to test, they need to find out what others have found on the same

issue or topic. Researching the work of other scientists to see if others have explored the same or

similar questions is helpful to the scientist to determine if a study is worth doing, or to see if there

are aspects of the research from other scientists that can inform their own investigation.



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To do this, students will either work individually or in small groups (this is your choice as a teacher,

though we would recommend small groups for efficiency and peer feedback for this process) on

investigating a particular pollutant that is known to affect air quality in some way. While there are

literally thousands of airborne pollutants that are the process of various industrial, commercial, or

mining efforts around the world, we have identified six primary pollutants that are more abundant,

and factor into the quality of air in most communities.

Student groups will be assigned a particular pollutant from the following list. Note that the last two

are optional, as they do not have easy follow-up activities in the next two lessons to investigate their

impact using a scientific experiment. While such experiments are possible, they can either be

dangerous, expensive (or equipment intensive, requiring specialized equipment or supplies), or

require a more complex understanding of the science before a proper investigation could be done.

Particulate matter Carbon Dioxide Sulfur dioxide Nitrogen oxides Ozone

Chlorofluorocarbons (CFCs) Carbon monoxide

Student groups will need to research these pollutants online, with a goal of creating a body of

knowledge that will be shared with other students during the presentations in Lesson 13.

Tell students that they should keep a word processor document open to paste content and reference

materials from their investigations. Students will need to make sure to keep track of what

information they find, where they find it, and to get appropriate information about the source of

information.

If using a lab or mobile computer lab environment, set up a set of expectations for what the students

should accomplish during the course of their research, and what types of sites or information is

appropriate to review for finding this background information. For instance, unless your school

already limits the types of content that can be viewed on the internet, you may want to suggest that

students first seek out documents and textual information about their pollutant, rather than videos

or other content.

Tell students they will need to be able to identify the source of any information they include in their

presentations, so it will be important for them to note not only the URL (web address) of the site

that they are on to find a certain bit of information, but that they also know a bit about who created

the site, and what it is used for.

Develop a set of guidelines that is specific to your schools access to resources and information

through the Internet, and discuss these with students before beginning the research, and revisit this

with students each day that you are doing internet research. Such guidelines might include requiring

students to visit a minimum number of sites, to visit sites that mention specific research on a

particular pollutant (and cite that information within footnotes or links on the site), and to visit sites

that not only address the pollutant itself with basic facts, but sites that also provide regional or



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location specific information about the pollutant. Some possible examples of these requirements

include the following.

Content Requirements:

Name of the pollutant Chemical composition of the pollutant Basic properties about the pollutant

How is the pollutant produced? How is the pollutant detected? What are the possible effects on human health from the pollutant? What are the possible effects on ecosystems and non-human organisms from the pollutant? Where does the pollutant typically exist (or where is it commonly produced)? How is the pollutant remediated? What affect does the pollutant have in Michigan? How is the level of pollutant detected? What are the acceptable levels of the pollutant?

Research Requirements Cite all sources for information gathered. Cite specific quotes that are used with the author information for the quote. Cite the URL of any site that is used.

If conflicting information is found, state this and note the differences. Find sites that contain data collected on the pollutant in question.

Use the student worksheet / Online Investigation of Pollutants to document information (or analternate electronic document that students can keep as a notebook for their findings.



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LESSON 11:

WHAT DO POLLUTANTS LOOK LIKE?

OVERVIEW AND OBJECTIVESLearning ObjectivesStudents model and compare the structure of pollutants through constructions of gumdrop models.

Assessment CriteriaAssess students models and discussions for the correct usage of the terms atoms, molecules,

compounds, elements and mixtures.

Purpose

Students will apply their online research to revisit the molecular models

PREPARATION

Make sure gumdrops kits are in working order after use in the last learning set.

TimeOne or two 50-minute class periods (depending on how organized).

Materials Gumdrop kit from Learning Set 2 Worksheet: What Does Air Look Like? Worksheet: Model of Pollutants Reader: How Do Pollutants Look?

INSTRUCTIONAL SEQUENCE

Introducing the LessonAsk students to share what they know about air and what is in air. Students should mention that

oxygen, nitrogen, and other materials are in air. They may also state that air is matter (mass and

volume) and air is a gas.

Draw an oxygen molecule (O2) on the board and remind students that oxygen is 21% of our air. Draw

a nitrogen molecule (N2) and ask students: What percentage of our air is nitrogen? A lot, some, or a

little? What else is in our air? (Students should say water, and other gases) We know what water

looks like. Draw a water molecule (H2O) on the board and remind students that there are 2 atoms of

hydrogen and 1 atom of oxygen in water. Now ask students about the other 1%...What do those

items look like in terms of their atoms and molecules?



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Have students review the definition of the following terms, atoms, elements, molecules, compounds,

and mixtures. Use the drawings as examples of these items.

Point out the periodic table and ask the class if the know what the symbols represent. Remind the

students that the table is a tool used by scientists to organize the types of atoms that make up

matter.

Students are going to build gum drop models again of these particles (compounds and molecules)found in air, but this time they will include the pollutants they investigated online in the previous

lesson. In the last lesson, one of the bits of information that students collected was the chemical

composition and structure of the pollutant. They are going to use this to create a model of their

pollutant for use in their presentation in Lesson 13.

Conducting the LessonDistribute one gumdrop kit to each group and remind the students that these kits will be reused

throughout the day, so they should not eat them because others have handled them. Review the

directions on the worksheet: What does air look like? and Models of Pollutants. Introduce the color

chart that functions as a key to show which elements are represented by certain colors.

Model the first gumdrop so students remember and are clear on the activitys objective.

Student models may use different colors to represent atoms. As long as the students build their

model according to their color key, it is an acceptable model.

Students should complete a model of their specific pollutant, and should explore how the pollutant

might be created from its constituent parts, or through a breakdown of some other substance.

Students who were assigned Chlorofluorocarbons (CFCs) for their pollutant in Lesson 10 should NOT

be expected to create this pollutant, as it is far more complex than the other pollutants, and, while

it could be done, would likely not result in the building of much conceptual knowledge about how

the pollutant came to be. Instead, because of the links between that pollutant and ozone, you may

wish to have those students focus on creating an example of the ozone molecule.

Students build the models indicated on the worksheet: Models of pollutants. If students run out of

gumdrops, they may need to take apart previous molecules and re-use the elements.

After students construct the models, bring the class together to share their models. Students can

hold up their models as you call out the various molecules that were been built, emphasizing how

two different models can use two different color keys. Reinforce that each used the proper type and

number of atoms according to their key, so both models are correct. Alternately, have students get a

picture of their models that they can use later in the presentations of their pollutants that will be

presented in Lesson 13.

Concluding the LessonWhen students complete the questions from their student sheet, ask them to share their answers

aloud. Hold up the models or draw them on the board to clarify the terms atoms, elements,

molecules, and compounds.



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Students should also review the reader section How Do Pollutants Look? to better understand how

the pollutant is actually created through human activity. For instance, students should see how the

interaction of the models of water and sulfur dioxide could produce an acid (H2SO4).

HOMEWORK

Have students complete the Student Reader / How Do Pollutants Look.



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LESSON 12:

INVESTIGATING POLLUTANTS

OVERVIEW AND OBJECTIVESLearning ObjectiveStudents will design elements of a set of investigations based on the pollutant they were assigned,

and will conduct the investigations to determine a number of factors related to the production of or

potential impact of their pollutant.

Assessment CriteriaStudents investigations will meet the various guidelines of the investigation framework, and

students will be able to report their process and findings in the next lesson.

PurposeThe purpose of this lesson is to have your students collect evidence about the various pollutants that

can affect air quality. Students will develop and conduct one (or multiple) investigations to explore

the production of various pollutants, including particulate matter, ozone, and sulfur and nitrogen

dioxide, with optional suggestions for additional pollution detection. This lesson is not only to help

students organize thoughts about air quality factors, but also to address basic concepts and practices

about the design and implementation of scientific investigations that explore variables in indirect

ways.

PREPARATION

This lesson is also broken up into four distinct investigations, with the notion that students would not

conduct every single investigation on their own. Rather, these are presented to encourage students

to investigate the pollutants they were researching in Lesson 10, so that they can each specialize

their efforts and develop an effective means to communicate their findings to their peers in the

following lesson (13). This is done for efficiency of time and materials, as it would take a long time

(and many more supplies) to conduct all of the investigations with all students, and to better

replicate the approach to investigation that many scientists engage in - specialization on particularissues and variables within an investigation. Scientists use such methods for efficiency as well, and

need to communicate their results in ways that allow others to try to replicate the results, or to

modify the variables or procedures of the investigation to explore other variables or phenomena.

It is important for you to read through the procedures of all four investigations to determine how you

are going to implement these effectively with students. One alternative, mentioned in Lesson 8, is

to have all students conduct the indoor implementation of Investigation A - Particulate Matter in the

Air, and then have students explore the other investigations as groups in smaller groups, focusing on



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one particular investigation. Another option would be to have students conduct one of the four and

separate these completely (though investigation A, and to a lesser extent, B, take less time and

understanding than C and D), or have students do one of the first two (A or B), which require a time

period for data collection, and one of the next two (C or D), which both take place outside using

vehicle exhaust in their study. Optional supplemental lessons may also be submitted online at the

Investigate the State web site.

For any of the investigations, note the setup and special considerations in your planning, especially

since Investigation A should be started in advance of the other investigations due to the time

required for particulate matter buildup. Also note the materials for each investigation, and that you

may need to identify 3-5 adult colleagues in your school with different vehicles to aid in

investigations C and D.

Documentation of Investigations (for later presentations)

Just as with the air walk activity in lesson 2, it is recommended that, if possible, you record the

procedures of the investigations using a digital camera or video camera. This allows you to revisit

the investigation to address techniques of experimentation, review observations, and provide sampleresources that students could use in their presentations in Lesson 13. It is only recommended that

you use discretion in taking pictures or recording such activities, both in who you have collect this

(whether you, an assistant, or a student would operate the camera), and how you might show the

images or recording (generally, for classroom use only, unless using a permission form to allow for

online posting or sharing).

INVESTIGATION A - PARTICULATE MATTER COLLECTION

Set-upThere are three procedures described for this investigation, each of which relies on different

materials and circumstances (such as the time you have to collect the matter, the materials you

have access to, and the level of detail you want to have students use in collecting data from this

investigation. If you wish to have students vary the focus of their investigations, multiple options

could be done all at once to compare procedures and data gathered. The options are described here:

1. Petri Dish: Uses petroleum jelly in a petri dish as a collector. Requires significant time for

collection and care in placing jelly in the dish (cant be messy or data will be skewed). Allows for

easy counting of particulates afterward. Good for seeing how many particulates settle in one

location over time.

2. Fan and Filter Paper: Uses filter paper with petroleum jelly, and a fan to pull air through the

paper. Better for little or no advance time (collection occurs during class period rather than over

days). More appropriate for finding particulates in air at a given time, but not for investigating

location as a factor for particulates. Harder to count particulates at the end.



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3. Mailing Labels: Uses adhesive side of mailing labels to collect particulate matter over time.

Similar to Petri Dish, but harder to count particulates at the end, and more susceptible to

pulling in non-airborne particulates if handled incorrectly by students. Best option for outdoor

placement.

You will want to carry out this investigation on your own before having students do it, so that you

are familiar with the findings, and so that you can find possible locations that will give strong

evidence leading to conclusions.

Special Considerations Consult with colleagues, administrators, and janitorial staff to allow students to place

collectors in locations outside of the classroom, and to make sure, if using adhesive labels oncardboard, that the collectors are not collected and removed as trash by janitors.

Make sure that you know where the locators for each student or group are located, and thatthey are not to be moved during the collection period.

Make sure that students label their collectors appropriately. Do not use the sticky side of tape of any sort as the collector surface, as particulate matter in

the adhesive might be mistaken as an airborne particulate.

Materials Student Worksheet: Investigation Considerations Student Worksheet: Investigation Procedures, Data, and Conclusions Petri dishes (option 1) Petroleum jelly (options 1 and 2) Ultra-bright White paper (option 1) Filter paper (option 2) While Adhesive-backed mailing labels (option 3) Scotch tape (option 3) Cardboard sheets - approximately 3 x 3 or larger (option

3) Metric Ruler Magnifying glass (3 to 5x magnification or more

preferred)

TimePreparation and distribution of collectors (25-30 minutes)

Collection of particulate matter (4-7 days for options 1 and 3, 20

minutes for option 2)

Analysis and data collection (10 - 15 minutes)

Option 2 is the only option that can be completed in a typical 50

minute class period. Options 1 and 3 should be started up to a week

prior to the day you want collection and analysis to take place.

Introducing the Investigation

Revisit the driving question and discuss key ideas learned. These

include:

Air is matterAir contains oxygen, nitrogen, and small amounts of other substances

Engage students in thinking about what else might be in the air. PossibleWhat is the Quality of Air in Our Community? Learning Set 3 - Page 93

Petri Dish

petroleum jelly

Air flowAir flow

Fan

Filter

paper


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questions: Is there anything we can see in the air? When can we see stuff in the air? What might cause this stuff? Cars? Buses? Dust? Smog? If there is visible stuff in the air, how can we prove there is visible matter in the air? Is there the same amount everywhere? Are there days with more or less visible matter in the air?

Scientists call some of this solid stuff particulate matter. It may include dust, pollen, orpollutants created by human activity.

Conducting the InvestigationInform the students who are doing this investigation that they will be designing and conducting

investigations to explore if there is visible matter in our air, where that might be located, and

whether there are different amounts of such objects in different locations (and what possible

reasons might be).

Hand out Student Worksheet - Investigation Criteria. Discuss the importance of investigations to

science in discovering new information and testing information that other have uncovered. If

investigations are new to your students, you may want to go through the criteria sheet for

investigations step by step and model a simple investigation. This is done on a basic level in the

smoke investigation in Lesson 8.

Remind students of their discussion that cars and busses produce stuff that goes into the air. Ask

students, what other visible stuff might be in the air. Ask if any students have allergies, and what

might cause these allergies.

Describe this investigation as a way to recognize some of that stuff in the air, and to decide what

factors might be related to that stuff. Explain the basic procedures that you will use for the

investigation from the options below:

1. Petri Dish option. Students can apply a thin layer of petroleum jelly to the inside surface of aPetri dish. Cotton swab applicators can be helpful for doing this, so that there isnt too much jelly

at any point. If using ones finger to apply this, make sure hands are clean. The dishes should be

clearly labeled with the name of the student(s), and may also have a circle of bright white paper

taped to the bottom of the petri dish, so that it is easier to see any particulate matter that gets

stuck in the jelly. If you plan to have students count the particulate objects they can see at the

time of collection, you should have students measure and draw a grid that is two centimeters on a

side, with each quadrant clearly identified (see diagram at right).

2. Fan / Filter Paper option. Students should make 2-3 squares on the back of the filter paper that

are 1cm x 1cm in size at random locations (not all together). Have students place stripes orpatches of petroleum jelly on the front side of the filter paper to cover over the squares. Putting

these stripes of jelly on, rather than across the whole paper, allows the fan to pull air through the

paper, but allows the particulate matter to stick to the stripes of jelly. Position the filter paper

next to the fan as shown in the diagram and allow the fan to pull air through for a minimum of 5

minutes. Depending on the type of fan you have, you may want to create an outside bracket that

you could affix the filter paper onto, just to reduce the risk due to the fans moving blades.



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3. Adhesive labels. Students should cut out sections of cardboard that are at least 3 by 3 in size,

and label them with their name(s). Using masking tape, have the students affix a white mailing

label - ADHESIVE SIDE OUT - onto the cardboard. (Note, masking tape is used instead of Scotch or

Clear tape or other tapes, because the static electricity buildup on the plastic of the tape can

actually affect the collection of electrostatically charged particulates in the air.)

For options 1 and 3, have students create 2-4 such detectors per student or group (however you are

organizing the students in your class for this activity). Have students brainstorm questions they

could investigate using these procedures, thinking about what variables they might be identifying to

study (based, in part, on the procedure used). Possible considerations include:

What kinds of things might affect the amount of trapped Particulate Matter in the air? Where is the most stuff in the air? Are there more particulates inside or outside? Are there more particulates by the street than in our class? Is there enough stuff in the air to see? Are there more particulates in one room than another?

Are there more particulates that we can pull out of the air than those that might settle on acollector?

Not all questions need to have an independent and dependent variable. If students choose to

investigate a simple question, do not have them answer the independent/dependent question.

Example questions might include:

How does location affect the amount of particulate matter? How does the speed of the wind from the fan affect the amount of particulate matter?

Students should complete the Investigation Considerations worksheet.

In order to determine how much stuff they collect, students should remove the collectors after

the designated period of particle collection and attempt to measure how much stuff was

collected. If quantitative measurements are desired and appropriate to the material collected,

students should use a magnifying glass to count the number of observable particles in the jelly within

a square centimeter (using the grid or square markings from the back, or by creating a 1 x 1 cm

square hole in a sheet of paper, and holding this over the adhesive label-based collector) that are

discernible. They should have at least two people count the particulates to reduce human error (and

discuss any discrepancies), and should average the number of particulates per square centimeter.

Alternately, students might find it difficult to measure and count the number of particulates,

depending on what they collectively decide a particulate to be in size. In this case, you may suggest

they come up with a set of qualitative or general descriptors, such as none, a little, some, and a lot.

Students should use these to complete the Procedure, Data, and Conclusion worksheet.

Concluding the InvestigationReview the term particulate matter. Particulate Matter (PM) is solid particles or liquid droplets

suspended in the air, such as soot, dust, fumes, or mist. Discuss where PM might come from.

Students results will be discussed more after the presentations in Lesson 13.



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INVESTIGATION B - OZONE DETECTORS

Set-upMake sure to order the EcoBadge materials well in advance of this lesson, as there is only one

supplier and they are prone to back-orders.

Special Considerations Consult with colleagues, administrators, and janitorial staff to allow students to place

collectors in locations outside of the classroom, and to make sure, if using adhesive labels oncardboard, that the collectors are not collected and removed as trash by janitors.

Make sure that you know where the locators for each student or group are located, and thatthey are not to be moved during the collection period.

Make sure that students label their collectors appropriately. Do not use the sticky side of tape of any sort as the collector surface, as particulate matter in

the adhesive might be mistaken as an airborne particulate.

Materials Student Worksheet: Investigation Considerations Student Worksheet: Investigation Procedures, Data, and Conclusions Ecobadge Ozone Detection Badge and Color Indicator Ecobadge Ozone Detection Sheet Enough EcoBadge test cards so that the students investigations wont be limited by the

number of test cards.

TimePreparation and distribution of collectors (15-20 minutes)

Collection of ozone (1 hour for option 1, 6-8 hours for option 2, 1-3 days for option 3)

Analysis and data collection (5 minutes)

Because of the requirement for ozone collection time, you will either need to stagger observation

and recording of the indicators, or find ways for students to come back to collect the badges later inthe day, and record their findings. They can work on conclusions and analysis on their own as

homework, or the following day in the classroom.

Introducing the Investigation

Revisit the driving question and discuss key ideas learned. These include:

Air is matter Air contains oxygen, nitrogen, and small amounts of other substances

Engage students in thinking about what else might be in the air. Possible questions:

Is there anything we can see in the air? When can we see stuff in the air? What might cause this stuff? Cars? Buses? Dust? Smog? Have they ever heard warnings on television or radio about air quality problems in their

community? If so, but they cannot be specific in their examples, ask if any have heard of ozone action

days or similar warnings? If so, do they know what these warnings suggest that they do (or NOT do)?

One of the known pollutants that students can investigate when exploring air quality is ozone.

Ozone is known as affecting the environment and air quality in two ways. Surface level ozone, which

exists in the air at the levels of the atmosphere where we live, is a problematic pollutant. At theWhat is the Quality of Air in Our Community? Learning Set 3 - Page 96


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same time, ozone also exists naturally in the upper atmosphere (stratosphere) where it is incredibly

helpful to humans in that it reflects significant amounts of ultraviolet radiation back into space,

helping us prevent the damage to our skin, eyes, and immune system that would otherwise take

place. At this level, the problem with ozone is that other pollutants (CFCs) break down this layer of

ozone, causing more damaging radiation to get through. Students who resear

learning set 3 - air quality unit

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