Suggestions for Teaching about Air Pollution

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  • Suggestions for Teaching about Air PollutionAlbert B. Carr

    Assistant Professor of Education and Consultant in Science,College of Education, University of Hawaii

    Early in 1963, former President Kennedy directed his attention tothe air pollution problem in a White House special message on theimprovement of American health. Mr. Kennedy pointed out that ^weare currently spending 10 cents per capita a year in fighting a problemwhich costs an estimated $65 per capita annually in economic lossesalone.?? The President further stated that ^economic damage from airpollution amounts to as much as $11 billion every year in the UnitedStates7 and that ^reports by leading scientists in the past year havestressed that there is overwhelming evidence linking air pollution tothe aggravation of heart conditions and to increases in susceptibilityto chronic respiratory diseases, particularly among older people."The story of air pollution and the campaign against it goes back

    quite far in the history of mankind. With a little imagination, one canalmost visualize Neanderthal man being chastised by his mate whenthe wind forced the smoke of their protective fire into the rear of theircave. The problem has been accentuated and compounded manytimes through the centuries. Today the needs and activities of ourever increasing population require that we disavow ourselves of thethought that air is an inexhaustible and immutable resource. Themost enlightened and efficient conservation practices must bebrought to bear on the air pollution problem.

    If any air pollution control program is to be successful, public edu-cation must not be overlooked. In fact, one of the recommendationsof a 3 day conference,1 jointly sponsored by the National ScienceTeachers Association and the Division of Air Pollution, U. S. PublicHealth Service, was that ^in view of its (air pollution) many new andchallenging aspects, it should be dealt with in the science curriculumof secondary schools." It was further recommended that air pollutionnot be taught as a separate unit, but included in those areas of thesecondary science curriculum where it logically fits. The followingareas were identified:Junior High Science: Biology:

    (Grade 10)RespirationConservation of ResourcesCauses of DiseasePlant Physiology

    ConservationAir and AtmosphereFire and CombustionCirculation and RespirationCommunity HealthEcology

    1 The Conference was held in Washington, D. C., 26-28 July 1961. Selected members of NSTA and the Di-vision of Air Pollution participated. A mimeographed "Report on Air Pollution Conference for Science Teachers"was prepared and distributed.


  • 230School Science and Mathematics

    Chemistry:(Grades 11 & 12)

    Composition of the AirChemical Effects of PollutantsCombustionFuelsOxygen and OzoneNitrogen and its CompoundsSulfur and its CompoundsCarbon and its CompoundsMetallurgical PropertiesCatalysis and EnzymesPhotochemical ReactionsCorrosion of MetalsColloidsSoaps and Detergents

    Physics:(Grades 11 & 12)

    HeatInternal CombustionMechanics of GasesNuclear EnergyProducts of CombustionPhysical Effects of Pollutants

    Physical Science (non-academic):(Grades 11 & 12)

    GeologyPrecipitationMeteorologyTransportationMining, Smelting, and MillingHousehold Science

    This article has been written to provide science teachers with thefollowing list of activities designed to help them begin a study of airpollution and related problems in the courses listed above.2

    1. Visit a plant or factory in your community using coal or oil as afuel. Observe the variety of activities that can lead to contamination of the atmosphere.a. Delivering the coal and moving it from place to place.b. Burning the fuel.c. Emission of solid and gaseous wastes into the atmosphere.d. Disposal of waste materials after the fuel has been burned.

    2. Draw up a list of all the human activities you can think of thatcontribute to air pollution.a. Can you think of ways and means to control any of these

    sources of contamination?b. Is it possible that in some of our cities, buildings could be

    heated by steam produced in plants on the lee side of thecity, so that contaminants might be carried away by thewind?

    2 For an excellent, understandable, scientific treatment of the air pollution problem request a copy of AirPollution (Power, A Special Report. December 1960. 45 pp.) from the Public Health Service; Washington 25,D. C.For an overall summary of the air pollution problem seeAlbert B. Carr. "Air Pollution: An Educational

    Problem," Science Education (April, 1961), 45: 245-248.More information is available from the following organizations:

    Air Pollution Control Association; 4400 Fifth Avenue, Pittsburgh 13, Pennsylvania,Air Pollution Control District; Public Information and Education Division; 434 S. San Pedro, Los Angeles13, California.Air Pollution Control Division; Municiple Department of Works, Toronto 12, Canada.Air Pollution Foundation; 2556 Mission Street, San Marino, California.Department of Air Pollution Control; 15 Park Row, New York 38, New York.Division of Air Pollution; U. S. Department of Health, Education and Welfare, Washington 25, D. C.Engineering and Technical Department; Automobile Manufacturers Association, Detroit, Michigan.New Jersey State Department of Health; Air Pollution Control Section, Trenton, New Jersey.

  • Teaching about Air Pollution 231

    c. Is smoke a necessary concomitant of the burning of fuels?d. How realistic is a suggestion that wind be produced artifi-

    cially to keep our urban areas free of air pollution?3. Vehicular exhaust is a major source of air pollution in many

    areas.a. Observe the effects of automobile exhaust on the rear end of

    some automobiles or on parking lot walls or vegetation.b. Visit a garage that uses an exhaust analyzer for tuning

    engines. Ask one of the mechanics to explain it to youand/or let you read the literature that came with the instru-ment.

    4. One of the basic problems in the utilization of fuel lies in burn-ing it properly. An understanding of some of the facets of thisproblem can be gained by working with a Bunsen burner. Lighta Bunsen burner and observe the flame. Vary the amount of airmixing with the fuel and note any changes in the flame and theamount of smoke produced. Discuss the burning of other fuelsin the light of your observations.

    5. Smoke is largely composed of unburned fuel. Certain under-standings about the combustion of fuels and the formation ofsmoke can be gotten by observing a candle burn.

    Light a candle and stand it on a metal or glass plate. Place aglass chimney over the burning candle and hold it at differentdistances above the plate.a. Is there a position where the candle burns with almost no

    smoke?b. What happens when you set the chimney on the plate?c. What are the implications of what you have observed for

    the use of fuels for heating purposes?6. The average person breathes in and out more than 20,000 times

    a day and takes in much more air, measured in pounds, than hedoes food. A class might be interested in determining the truthof this statement for themselves.a. Determine how many times a day the ^average person" in

    your class breathes.b. The vital capacity of the lungs is about 0.5 liters and the

    weight of one liter of air is 1.2 gm. Express this amount ofair in pounds and compare it to the number of pounds offood and water you take in every day.

    c. Determine the amount of air taken in during the day by the^average person" in your class.

    d. How long can a person do without water or food? How longcan he do without air?

  • 232 School Science and Mathematics

    7. Soot, dust, fly ash, and other aerosols in the atmosphere can becollected and studied. The materials needed are a container orsome other device for collection, a hand lens or microscope, anda fairly accurate balance.

    Set out on the roof of the school a wide-mouthed collectingjar, greased (vaseline) plate or sheet of sticky (^fly") paper.Leave the collecting device outside for a day, a week, or someother definite period of time and then examine what has beencollected.Comparisons can be made of the particulate matter present

    in the air in different parts of a city or between city air andcountry air by weighing the collected materials on a fairlyaccurate analytical balance and by examining them under ahand lens or microscope.

    8. It can be illustrated that the air contains dust. The materialsneeded are a projector or a beam of sunlight and a darkenedroom. Darken the room and observe the beam of light from asource such as a flashlight, a projector, or the sun. Dust par-ticles can be seen floating in the air in the beam of light.

    9. The high-volume sampler, in use in many air pollution sam-pling programs, can be illustrated in the classroom. It consistsbasically of an electro-lux type vacuum cleaner which draws inlarge volumes of air retaining any particulate matter in a filter-ing device placed over the intake opening.

    Using an old vacuum cleaner, this device can be set up byyoungsters and comparisons made of the particulate loadings ofthe atmosphere in different parts of the community.

    10. Meteorological conditions have an effect on air pollution. Ob-serve the weather maps for several days and then discussa. The effects of the vertical and horizontal movements of air

    masses on air pollution.b. The effects of a prolonged temperature inversion on the

    community.11. Cyclones and certain control devices work on the basic princi-

    ple of removing particulate matter by utilizing centrifugalforces. Understanding the working of these devices can beaided by observing a centrifuge in operation removing sus-pended materials from water.The action of centrifugal force on particles suspended in a

    gas can be observed by filling a test tube with smoke, corkingit, balancing it in the centrifuge and letting it spin for about ahalf minute. Another test tube should be filled with smoke,corked and left on the desk to act as a control.

  • Teaching about Air Pollution 233

    12. Chromatographic methods of analysis can be demonstratedand used in the science classroom. With the equipment avail-able in the junior or senior high school it would be rather diffi-cult to work in the area of gas chromatography. However,understandings, applicable to gas chromatography, can begained by chromatographically separating complex liquids.

    In the May, 1958 issue of the Science Teacher, two demon-strations on chromatography for use in the junior high schoolare described in detail. The first one deals with the use of paperchromatography in separating various colored inks and thesecond one deals with the separation of leaf pigments by col-umnar chromatography. Single copies of these demonstrationsmay be obtained by writing to Public Inquiries, U. S. PublicHealth Service, Washington 25, D. C.

    13. A working model of the Cottrell precipitator can be con-structed quite easily. The procedure is described in a free book-let entitled Superstition to Supersonics available from theManufacturing Chemists Association; 1825 Connecticut Ave-nue N.W., Washington 9, D. C.

    14. There have been occasions when nylon stockings have seem-ingly been spontaneously destroyed. Sulfuric acid from vehicu-lar exhaust is thought to be responsible.The effects of H2S04 can be observed by spraying some

    dilute acid on nylon stockings and other materials placed in abeaker or some other suitable container.

    15. Hydrogen sulfide discolors lead base paints. This can be ob-served in the laboratory.

    Paint something with a light-colored lead base paint. Put itunder the fume hood with an HsS generator in operation andobserve the results.

    16. A number of controlled experiments can be set up to determinethe effects of many gaseous contaminants on plants.

    Prepare gases3 such as C02, CO, S02, Cl2, and 03. Place aplant in a closed system, such as underneath a large bell jarsealed around its edge with a suitable sealing compound. Intro-duce a very small amount of the gas to be observed into the belljar using a hypodermic syringe or similar device. A bell jar openat the top or with a hole put in its side should be used andsealed immediately after introducing the gas. Keep the systemclosed for several hours and then observe what effects, if any,are produced on the plants used.

    The preparation of most of these gases can be found in any standard chemistry text. The preparation o fozone is outlined by Thomas P. Whalley in **A Small Compact Ozonizer for Laboratory Use," Journal of Chemi-cal Education, (February 1957), 34: 94.

  • 234 School Science and Mathematics

    17. Controlled experiments can also be set up to determine theeffects of varying doses of soluble arsenic, fluorine, and leadcompounds on laboratory animals.Mix small amounts (varying from 0.1 gm to 1.0 gm) of the

    compound to be tested in the feed of some of the animals everyday. Feed the other animals the same diet minus the test com-pound. Note any effects such as loss of weight, depression, andthe like in the animals.What conclusions can be drawn from this experimental

    work?18. The effects of dust on the growth and development of plants

    may be observed. Compare plants growing close to a dustyroad with plants growing farther away from the road. Markeddifferences may be observed. The proximity to vehicular ex-haust gases may be a factor but the clogging of stomata by dustdoes affect the normal growth and development of a plant.

    19. Atmospheric contamination many times affects visibility. Avisibility scale can be devised which may be roughly equated tothe degree of air pollution on different days. One way to do thisis to pick out stationary objects on the horizon and use themfor your scale. Perhaps you can see a nearby tree; then a lamppost a little farther away; a building still farther away fromyou, and so on. The scale that you set up need not be in termsof exact distances. Visibility will be relative to what you canobserve on your scale and may be expressed as being higher orlower than it was yesterday or on the same date the previousmonth. In order to standardize your procedure all observationsshould be made at noon on days when it is not raining.

    20. Odors and their effects on people is a very interesting subject.A discussion in this area may be precipitated by opening a jarof an aromatic compound such as pyridine (C5HgN) in thefront of the room.a. Each person in the room should write down the time the

    odor was first noted and a description of it.b. The psychological and possible physiological effects of odors

    can then be discussed.21. Have your class visit areas in the community affected by air

    pollution and/or an industrial plant using control measures toabate atmospheric contamination. Study the sources and na-ture of the contaminants and their effects on living things,structures, and other materials.a. Photograph instances of atmospheric contamination in your

    communityindustrial operations, power plants, motor

  • Teaching about Air Pollution 235

    vehicles, home heating plants, and refuse burning. Displaythem on posters or on the bulletin board.

    b. Ask...


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