United States
Environmental Protection
Agency
Office of Environmental
Processess and Effects Research
Washington, DC 20460
EPA/600/9-90/027
    July 1990
Acid Rain:
A Student's First Sourcebook

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This information guide was prepared under the direction of Jack Durham, Office of Environmental Processes
and Effects Research. The text was prepared by Beth Ann Kyle and Mary Deardorff of Environmental
Management Support, Inc., Silver Spring, Maryland, and Jeff Sabol of International Science and Technology
Sterling, Virginia.

Comments or questions regarding this report should be directed to:

       Jack L. Durham
       Office of Environmental Processes and Effects Research
       U.S. Environmental Protection Agency (RD-682)
       401 M Street, S.W.
       Washington, D.C. 20460


Copies of the report are available from:

       Office of Research and Development
       Distribution Unit
       U.S. Environmental Protection Agency
       Cincinnati, OH 45268
Cover: Hydrologist testing water samples from a test lake (photo courtesy of International Science and
Technology, Inc.)
     The information in  this document has been funded wholly or in part by the United States
     Environmental Protection Agency under contract number 68-03-3312 to PEER Consultants, PC. It
     has been subjected to the Agency's peer and administrative review, and it has been approved for
     publication as an EPA document. Mention of trade names, commercial products, or organizations is
     for illustrative purposes only and does not constitute endorsement or recommendation for use.

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           ACID RAIN
  A Student's First Sourcebook
                  U.S.
                JULY 1990

Office of Environmental Processes and Effects Research
      Office of Research and Development
   United States Environmental Protection Agency
            Washington, DC 20460

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                                         Acid Rain Sourcebook
             TABLE OF CONTENTS

Purpose	i
Introduction	1
Observations About Acidity	3
Defining Acid Rain	5
Effects of Acid Rain on Forests	11
Effects of Acid Rain on Water	15
Effects of Acid Rain on Human-Made Materials  ...   17
Effects of Acid Rain on People	18
What Can Be Done	19
Experiments	25
Activities	47
Bibliography	51
Glossary	55

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                                                      Acid Rain Sourcebook
                         PURPOSE
     The primary goal of the U. S. Environmental Protection
Agency (EPA) is to protect human health and the environment. One
of the ways in which EPA tries to achieve that goal is to educate the
public  on matters of local and national concern. Acid rain affects
both the health of humans and our environment and is an issue
with which the EPA is actively involved. EPA provides information
on research, regulation, and other issues associated with acid rain.
Because acid rain is of national and international concern, many
other government organizations are also responsible for working on
this problem.
      EPA frequently receives requests for information on acid rain
from school systems, teachers, and individuals. Some seek sugges-
tions for simple experiments to demonstrate concepts related to acid
rain science. Others want information on the latest research and
efforts to lessen the effects of acid rain. Still others want to know
how citizens can become involved in helping to reduce the potential
impact of acid rain. In response to these requests, EPA has devel-
oped this study guide. The purpose of the guide is to help students
better  understand the science, citizen action, and research issues
that are part of the  acid rain problem.
      This book is for students in grades 4-8 and their teachers.
After reading the concepts and definitions and doing some of the
experiments and activities in the guide, we hope that they will have
a better understanding of the acid rain problem and a greater
interest in its resolution.

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                                                      Acid Rain Sourcebook
                 INTRODUCTION
     Since the beginning of time, humans have learned to
make use of many things in nature such as fire and
electricity. From the early times through the Industrial
Revolution to the Space Age, humans have produced
inventions that use many of the earth's varied ENERGY
resources to make living easier. In many cases the energy
comes from burning FOSSIL FUELS—coal,  oil, and natural
gas.
     Some of the inventions that make our lives easier are
also causing POLLUTION. Pollution is the release of
harmful substances into the ENVIRONMENT. One form of
pollution is ACID RAIN. Acid rain can damage plants,
animals, soil, water, building materials, and people.
Scientists have discovered that burning fossil fuels creates
acid rain through air pollution. People burn fossil fuels
such as oil and coal to make electricity. Electricity heats
and lights buildings and runs appliances such as
televisions and video recorders. Fossil fuels power our cars,
buses, and airplanes. The air pollution created when these
fuels burn does not stay in the air forever. It can return to
the earth as acid rain. And when it does, it  may weaken the
plant and animal life it contacts. Acid rain is only one form
of pollution that results from burning fossil fuels. It is of
particlar interest, however, because it can be transported
over long distances. Scientists, engineers, and researchers
Words tfiat are explained in In*
glossary, which begins on page 65,
are printed in boldface type the first
time they appear.

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Acid Rain Sourcebook
                           are learning how to measure the amount and effects of
                           pollution in the air, forests, water, and soil. They are
                           inventing ways to reduce the amount of pollution that
                           enters the  environment and to prevent new damage in the
                           future.
           Lemonade (2.2-3.0)
                                         Milk (6.4-7.6)
Ammonia (11.0-11.5)
                        Apple (2.9-3.3)
                    I    0
         0    1    2     3    4     5    6     7    8     9   10    11   12    13   14
Fish Affected
Buildings and Paint Affected
Trees and Plants 1
Affected I
4
fstrnnnari
1




die

Bas





/e(rnnnar\



                                              1
                                           Neutral
           This diagram shows the pH scale. On top are some common items and their pH. A pH stronger than around 5 can harm
           buildings, metals, paint, and other materials. What pH level can harm fish? How about plants? Are these levels of acidity
                 stronger or weaker than the level that affects materials? See the next page to learn more about pH.

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                                                        Acid Rain Sourcebook
       OBSERVATIONS ABOUT ACIDITY

      ACIDIC and BASIC are two extremes that describe
CHEMICALS, just like hot and cold are two extremes that
describe temperature. Mixing ACIDS and BASES can
cancel out their extreme effects, much like mixing hot and
cold water can even out the water temperature. A
substance that is neither acidic nor basic is NEUTRAL. The
pH scale measures how acidic or basic a substance is. The
pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH
less than 7 is acidic. A pH greater than 7 is basic.
      Pure water is neutral. But when chemicals are mixed
with water, the mixture can become either acidic or basic.
Examples of acid substances are vinegar and lemon juice.
Laundry detergents and ammonia are examples of basic
substances. Chemicals that are very basic or very acidic
are REACTIVE. These chemicals can cause severe burns.
Automobile battery acid is an acidic chemical that is
reactive. Automobile batteries contain a stronger form of
some of the same acid that is in acid rain. Household drain
cleaners often contain lye, a very ALKALINE (another way
to say basic) chemical that is reactive.
The pH Seote
The pH seals measures how bask;
or rtowaoWS&asub6lan<5& te. Her*
am some facts abwt pH.
 .aeadiCiOf how bssfelhs
 ih&t 7 is baste,
 Each wtwie.pH value above 7
 the next tower whole value, £er
 sxafRpfe* pH to isl Q toes
 more atkalittethatt pK 8 and
 1&> toss 0<3 times, to) more
 alteto than pH &,
* A solution wftfc a pH tess than ?
  10 traes rnore acidic than th6
  more actdc than ptt 5 and 100
  lim&s {to tiffies 10 ) more addic
Experimenf s on pH
The fotl&vwng are examples of
experiman^ section beginning
Tesi fte pH
               p-Test
               dd) HI
then again after adding baking
                                                           Measurin aH
                                                                  . Measure the pH of
                                                           common hous«hotd ftems such as
                                                                       IrtdJeatpr
                                                           walh the gricfi^ou q»f acids grid
                                                           base*,

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                                                    Acid Rain Sourcebook
             DEFINING ACID RAIN

     Acid rain is rain that is more acidic than normal.
Acid rain is a complicated problem. Caused by air
pollution, acid rain's spread and damage involves weather,
chemistry, soil, and the life cycles of plants and animals on
the land and from acid rain in the water.

Air Pollution Creates Acid Rain
     Scientists have discovered that air pollution from the
burning of fossil fuels is the major cause of acid rain.
Power plants and factories burn coal and oil. Power plants
use that coal and oil to produce the electricity we need to
heat and light our homes and to run our electric
appliances. We also burn natural gas, coal, and oil to heat
our homes. Cars, trucks, and airplanes use gasoline,
another fossil fuel.
     The smoke and fumes from burning fossil fuels rise
into the ATMOSPHERE and combine with the moisture in
the air to form acid rain. The main chemicals in air
pollution that create acid rain are SULFUR DIOXIDE and
NITROGEN OXIDES. Acid rain usually forms high in the
clouds where sulfur dioxide and nitrogen oxides react with
water,  oxygen, and OXIDANTS. This forms a mild solution
of SULFURIC ACID and NITRIC ACID. Sunlight increases
the rate of most of these reactions. Rainwater, snow, fog,
and other forms of PRECIPITATION containing those mild

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Acid Rain Sourcebook
       Volcanoes, vegetation, and
     marehland* emit sulfur and nitrogen
        oxides and hydrocarbons
                            Power plants, businesses,
                            Industry, and homes emit
                            sulfur and nitrogen oxides
                              and hydrocarbons
                                                 Emissions are mixed with oxygen,
                                                ozone, and water to form sulf uric and
                                                nitric adds In the presence of sunlight
                                                      Dry deposition of
                                                        acids and
                                                        precursors
                    .Wet acid precipitation falls .
                       ..  "to ground   . ,'
  Vehicles emit
nitrogen oxides and
  hydrocarbons
                Acidity adversely affects aquatic
                 and terrestrial ecosystems,
                human-made materials, visibility,
                   and human health
                                    Formation of Acid Rain
                            solutions of sulfuric and nitric acids fall to earth as acid
                            rain.
                            Acid Precipitation
                                  Water moves through every living plant and animal,
                            streams, lakes, and oceans in the HYDROLOGIC CYCLE.
                            In that cycle, water evaporates from the land and sea into
                            the atmosphere. Water in the atmosphere then
                            CONDENSES to form clouds. Clouds release the water
                            back to the earth as rain, snow, or fog. When water
                            droplets form and fall to the  earth they pick up
                            PARTICLES and chemicals that float in the air. Even
                            clean, unpolluted air has some particles such as dust or
                            pollen. Clean air also contains naturally occurring gases

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                                                     Acid Rain Sourcebook
such as CARBON DIOXIDE. The interaction between the
water droplets and the carbon dioxide in the atmosphere
gives rain a pH of 5.6, making even clean rain slightly
acidic. Other natural sources of acids and bases in the
atmosphere may lower or raise the pH of unpolluted rain.
However, when rain contains POLLUTANTS, especially
sulfur dioxide and nitrogen oxides, the rain water can
become very acidic.

Dry Deposition
      Acid rain does not account for all of the acidity that
falls back to earth from pollutants. About half of the acidity
in the atmosphere falls back to earth through DRY
DEPOSITION as gases and dry particles. The wind blows
these acidic particles and gases onto buildings, cars,
homes, and trees. In some instances, these gases and
particles can eat away the things on which they settle. Dry
deposited gases and particles are sometimes washed from
trees  and other surfaces by rainstorms. When that
happens, the RUNOFF water adds those acids to the acid
rain, making the combination more acidic than the falling
rain alone. The combination of acid rain plus dry deposited
acid is called acid deposition.

Acid Rain Is a Problem that Can Travel
      The chemical reactions that change air pollution to
acid rain can take from several hours to several days. Years
ago, when smokestacks were only a few stories high,

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Acid Rain Sourcebook
                        pollution from smokestacks usually stayed near the ground
                        and settled on the land nearby. This caused unhealthy
                        conditions for plants and animals near those smokestacks.
                        To reduce this pollution, the government passed a law
                        permitting the construction of very tall smokestacks. At
                        that time, people thought that if the pollution were sent
                        high into the air it would no longer be a problem. Scientists
                        now know that this is incorrect. Sending pollution high into
                        the sky increases the time that the pollution stays in the
                        air. The longer the pollution is in the air, the greater are
                        the chances that the pollutants will form acid rain. In
                        addition, the wind can carry these pollutants for hundreds
                        of miles before they become joined with water droplets to
                        form acid rain. For that reason, acid rain can also be a
                        problem in areas far from the polluting smokestacks. Dry
                                                                 deposition is
                                                                 usually more
                                                                 abundant near
                                                                 the cities and
                                                                 industrial
                                                                 areas where
                                                                 the pollutants

                                                                 are released.

 Eruption of the Mt. St. Helens volcano in Washington State (photo courtesy of the U.S. Fish and Wildlife Service)
 8

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                                                      Acid Rain Sourcebook
Natural Acids
     There are also natural sources of acids such as
volcanoes, natural geysers, and hot springs. Nature has
developed ways of recycling these acids by absorbing and
breaking them down. These natural acids contribute to
only a small portion of the acidic rainfall in the world
today. In small amounts, these acids actually help dissolve
nutrients and minerals from the soil so that trees and
other plants can use them for food. The large amounts of
acids produced by human activities overload this natural
acidity.

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                                                        Acid Rain Sourcebook
    EFFECTS OF ACID RAIN ON FORESTS

      Over the years, scientists, foresters, and others
have watched some forests grow more slowly without
knowing why. The trees in these forests do not grow as
quickly as usual. Leaves and needles turn brown and fall
off when they should be green and healthy.
      Researchers suspect that acid rain may cause the
slower growth of these forests. But acid rain is not the
only cause of such conditions. Other air pollutants,
insects, diseases, and drought are some other causes that
harm plants. Also, some areas that receive acid rain show
a lot of damage, while other areas that receive about the
same amount of acid rain do not appear to be harmed at
all. However, after many years of collecting information on
the chemistry and biology of forests, researchers are
beginning to understand how acid rain works on the forest
soil, trees, and other plants.
      ents on Acids In
Son
Oomptete Erections, for thess aftqt
fstlw experiments art! fisted to tfta
EXPERIMENTS section beginning
Determining Safl pH U&irtg a sei
          , wooded arsa,
Looking *» Soil Buifertag
Measure Ike pH of aliqw^ tfeat
   r, Pour an saefefic feivW
through, (ifeasure the pH agairt
first and 6«
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Acid Rain Sourcebook
                       in pH. Without buffering capacity, soil pH would change
                       rapidly. Midwestern states like Nebraska and Indiana have
                       soils that are well buffered. Places in the mountainous
                       northeast, like New York's Adirondack Mountains, have
                       soils that are less able to buffer acids. Since there are
                       many natural sources of acids in forest soils, soils in these
                       areas are more susceptible to effects from acid rain.

                       How Acid Rain Harms Trees
                             Acid rain does not usually kill trees directly. Instead,
                       it is more likely to weaken the trees by damaging their
                       leaves, limiting the nutrients available to them, or
                       poisoning them with TOXIC substances slowly released
                       from the soil.
                             Scientists believe that acidic water dissolves the
                       NUTRIENTS and helpful minerals in the soil and then
                       washes them away before the trees and other plants can
                       use them to grow. At the same time, the acid rain causes
                       the release of toxic substances such as aluminum into the
                       soil. These are very harmful to trees and plants, even if
                       contact is limited. Toxic substances also wash away in the
                       runoff that carries the substances into streams, rivers, and
                       lakes. Less of these toxic substances are released when the
                       rainfall is cleaner.
                              Even if the soil is well buffered, there can be damage
                       from acid rain. Forests in high mountain regions receive
                        additional acid from the acidic clouds and fog that often
                        surround them. These clouds and fog are often more acidic
_

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                                                        Acid Rain Sourcebook
   Forest damage to which acid deposition may have been a contributing cause (photo courtesy of
               the National Acid Precipitation Assessment Program).
than rainfall. When leaves are frequently bathed in this acid
fog, their protective waxy coating can wear away. The loss of
the coating damages the leaves and creates brown spots.
Leaves turn the energy in sunlight into food for growth. This
process is called PHOTOSYNTHESIS. When leaves are
damaged, they cannot produce  enough food energy for the
tree to remain healthy.
      Once trees are weak, they can be more easily attacked
by diseases or insects that ultimately kill them. Weakened
trees may also become injured more easily by cold weather.
      Acid rain can harm other plants in the same way it
harms trees. Food crops are usually not seriously affected,
however, because farmers frequently add fertilizers to the
soil to replace nutrients washed away. They may also add
crushed limestone to the soil. Limestone is a basic material
and increases the ability of the soil to act as a buffer against
acidity.
                                                                             13

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                                                         Acid Rain Sourcebook
     EFFECTS OF ACID RAIN ON WATER

      The effects of acid rain are most clearly seen in the
AQUATIC, or water, environments, such as streams, lakes,
and marshes. Acid rain flows to streams, lakes, and
marshes after falling on forests, fields, buildings, and
roads. Acid rain also falls directly on aquatic HABITATS.
                  pH6.5
pH6.0
pH5.5
pH 5.0
pH4.5
pH4.0
     TROUT

      BASS

     PERCH

     FROGS

   SALAMANDERS

     CLAMS

    CRAYFISH

     SNAILS

     MAYFLY
  This chart shows that not all fish, shellfish, or their food insects can tolerate the same amount of acid. Fish like trout, bass, and perch are
  affected at different pH levels. Which type of fish are the most sensitive to acid? Generally, the young of most species are more sensitive
   than adults. Frogs may tolerate relatively high levels of acidity, but if they eat insects like the mayfly, they may be affected because part
                               of their food supply may disappear.
                                                                               15

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Acid Rain Sourcebook
                             Most lakes and streams have a pH between 6 and 8.
                        However, some lakes are naturally acidic even without the
                        effects of acid rain. Lakes and streams become acidic (pH
                        value goes down) when the water itself and its surrounding
                        soil cannot buffer the acid rain enough to neutralize it. In
                        areas like the northeastern United States where soil buf-
                        fering is poor, some lakes now have a pH value of less than
                        5. One of the most acidic lakes reported is Little Echo Pond
                        in Franklin, New York. Little Echo Pond has a pH of 4.2.
                        Lakes and streams in the western United States are
                        usually not acidic. Because of differences in emissions and
                        wind patterns, levels of acid deposition are generally lower
                        in the western United States than in the eastern United
                        States.
                             As lakes and streams become more acidic, the
                        numbers and types of fish and other aquatic plants and
                        animals that live in these waters decrease. Some types of
                        plants and animals are able to tolerate acidic waters.
                        Others, however, are acid-sensitive and will be lost as the
                        pH declines. Some acid lakes have no fish. At pH 5, most
                        fish eggs cannot hatch. At lower pH levels, some adult fish
                        die. Toxic substances like  aluminum that wash into the
                        water from the soil may also kill fish.
                             Together, biological organisms and the environment
                        in which they live are called an ECOSYSTEM. The plants
                        and animals living within an ecosystem are highly inter-
                        dependent. For example, fish eat other fish and also other
                        plants and animals that live in the lake or stream. If acid
                        rain causes the loss of acid-sensitive plants and animals,
                        then fish that rely on these organisms for food may also be
                        affected.
_             __                                               ——

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                                                             Acid Rain Sourcebook
    EFFECTS OF ACID  RAIN  ON  HUMAN-
                  MADE  MATERIALS

      Acid rain eats away at stone, metal, paint—almost
any material exposed to the weather for a long period of
time. Human-made materials gradually deteriorate even
when exposed to unpolluted rain, but acid rain accelerates
the process. Acid rain can  cause marble statues carved
long ago to lose their features. Acid rain has the same
effect on buildings and monuments. Repairing acid rain
damage to houses, buildings, and monuments can cost
                                              billions of
                                              dollars.
                                              Ancient
                                              monuments
                                              and buildings,
                                              such as the
                                              Parthenon in
                                              Greece, can
                                              never be
                                              replaced.
Example of acid deposition effects on a monument (photo courtesy of
             the National Park Service).
  Acid Rain, EKects on Marble
  {Chalk)
  com;pounjtoecurring in rocks, ;
 ... and in animal bones, shells, and ::'*!
  teeth. Marble and limestone are  : • •!
  Aiding mat$rfateverntgrtf< The next day,,
 see if you cfin tell vyhtoh.jwece of
 cfialk is rfiore wsrn away.
1;, metate.Cortiplete instructions for;
^ th|s and o%ersxperttnents can .
 . flitnted before 1983;.
 :;: Place Bie other. : peiiny Jrt a cup :
 v.pf yinegajr or (emfiin ju fw. After 5
 :daj%, observe ttieeffeetaof the •
 different liquids i>n each.perir»y,.. ;:
 Observe again in two weeks,
                                                                                     17

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Acid Rain Sourcebook
                            EFFECTS OF ACID RAIN ON PEOPLE

                             Acid rain looks, feels, and tastes just like clean rain.
                       The harm to people from acid rain is not direct. Walking in
                       acid rain, or even swimming in an acid lake, is no more
                       dangerous than walking or swimming in clean water. The
                       air pollution that causes acid rain is more damaging to
                       human health. Sulfur dioxide and nitrogen oxides, the
                       major sources of acid rain, can irritate or even damage our
                       lungs.
                             The pollutants that cause acid rain can also reduce
                       visibility—limiting how far into the distance we can see.
                             The primary pollutants associated with acid rain and
                       poor visibility are human-made sulfur dioxide emissions.
                       These emissions form small sulfate particles, or aerosols, in
                       the atmosphere. These aerosols reduce visibility by
                       scattering light. Sulfate aerosols are the main cause of poor
                       visibility in the eastern United States.
                              Nitrogen oxide emissions are also associated with
                       the acid rain problem. They, too, can form  aerosols in the
                       atmosphere that significantly reduce visibility. Nitrate
                       aerosols are often the main cause for poor visibility in the
                       western United States where sulfur dioxide emissions and
                       humidity are lower than in the east.
 18

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                                                     Acid Rain Sourcebook
             WHAT CAN BE DONE

     To solve the acid rain problem, people need to
understand how acid rain causes damage to the
environment and what can be done to help stop acid rain.
More information on the problem will help leaders make
better decisions about how to control air pollution—the
cause of acid rain.

Scientific Research
     Experts from the United States Environmental
Protection Agency (EPA) have taken samples of pollution
and acidity from thousands of streams and lakes in the
United States. From these samples, they determine the
number of streams and lakes which are now acidic and
                             Scientists are collecting samples of plants and animals (photo courtesy of
                                       the U.S. Fish and Wildlife Service).
                                                                          —

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Acid Rain Sourcebook
                       which are in danger of becoming acidic. EPA and other
                       scientists are also studying the effects of acid rain on fish,
                       plants, humans, and materials such as marble, brick,
                       cement, and metal.
                            Until we reduce air pollution, acid rain will continue
                       to be a problem. Activities to resolve this problem include
                       cleaning up the smokestacks and exhaust pipes that pour
                       pollutants into the air, finding alternative sources of
                       energy, repairing the damage already done by acid rain,
                       and conserving our resources.

                       Cleaning up Smokestacks and Exhaust Pipes
                            Right now, burning FOSSIL FUELS is one of the
                       most inexpensive ways to produce electricity for the daily
                       activities of modern life and to power  cars, buses, and
                       airplanes. In the United States, sulfur in coal makes up the
                       greatest part of the sulfur dioxide that becomes acid rain.
                       When coal is burned to make electricity or heat, the sulfur
                       goes up the smokestacks and into the atmosphere to
                       become air pollution.
                            There are several ways to reduce the amount of
                       sulfur entering the air. One way is to  wash the sulfur out of
                       the coal before it is burned. Another is to wash the sulfur
                       out of the smoke before it goes up the smokestacks.
                       SCRUBBERS remove sulfur from the  smoke by spraying a
                       mixture of water and powdered limestone into the
                       smokestack. This mixture traps the sulfur before it can
                       escape into the air above.
20

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                                                     Acid Rain Sourcebook
     Scientists and engineers are also discovering new
ways to burn fossil fuels that produce much lower amounts
of pollution.
     Nitrogen oxides from burning coal and from vehicles
also contribute to acid rain. Vehicles give off nitrogen
oxides and other pollutants in their exhaust fumes. Devices
such as CATALYTIC CONVERTERS reduce the pollution
from those exhaust fumes. All new cars sold in the United
States are required to have catalytic converters.

Alternative Ways of Producing Energy
     There are other sources of energy besides fossil fuels.
These include HYDROELECTRIC POWER and NUCLEAR
POWER. Dams use the power of water to turn TURBINES
and make electricity. People have been using this form of
energy for most of this century. Nuclear power plants make
electricity from the energy released by splitting atoms. A
small amount of nuclear fuel can make a very large
amount of electricity.
     There are problems with using hydroelectric and
nuclear power. Hydroelectric plants require a constant
source of water. Because rainfall is not always predictable,
hydroelectric plants are not as reliable as those using coal
or oil. Hydroelectric plants can also harm the environment.
Thousands of acres of land often have to be flooded to
create a RESERVOIR, a holding place for the great
amounts  of water needed to power these plants. Sometimes
the land that would be flooded is home to rare types of
                                                                         2?

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Acid Rain Sourcebook
                       plants or animals. Nuclear power plants produce electricity
                       cheaply. But the nuclear waste they leave remains
                       dangerous for thousands of years.
                             Scientists are looking at other energy sources, such
                       as windmills and SOLAR ENERGY, using the power of the
                       sun itself. In several states, there are modern windmills
                       like airplane propellers that make electricity from the wind.
                       In other places, wind power pumps water from the ground.
                       In Arizona and New Mexico, solar energy is at work making
                       electric power. Each of these sources has drawbacks as
                       well. Windmills and solar panels are reliable only where it
                       is windy or sunny most of the time.
                             All sources of energy have benefits and limitations,
                       including the cost of producing the energy. All of these
                       factors must be weighed when deciding which energy
                       source to use.

                       Restoring a Damaged Environment
                             It can take years for an acidic lake or stream to
                       recover naturally, even if the acid rain stops. People have
                       brought some lakes and streams back to neutral or basic
                       conditions more quickly than nature could alone. They
                       have added powdered limestone (a natural base) to the
                       water in a process called LIMING. The people of Norway
                       and Sweden have successfully restored hundreds of lakes
                       and streams with liming. Few lakes and streams have been
                       limed in the United States.
22

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                                                        Acid Rain Sourcebook
      Liming is expensive and the effects are only
temporary. As long as acid rain continues to fall, limestone
must be reapplied or the water will become acidic again.
Liming may be the only way to make sure that life in acid
lakes or streams survives until the amount of acid rain
falling on the surrounding land can be reduced.

Conserving Resources
      It may seem like there is not much that individuals
can do to stop acid rain.  However, environmental
problems—including acid rain—are caused by the
combined actions of individual people. Individuals can take
part in solving those problems as well. One of the first
              Scientists are adding an alkaline material to a lake to neutralize acids in the water (photo courtesy of
                              International Science and Technology, Inc.)-
                                                                              23

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Acid Rain Sourcebook
steps is to assume responsibility for the problem by finding
out what can be done.
     Each person who turns off lights when no one is using
them and uses energy-saving appliances reduces the amount
of electricity a power plant needs to produce. When less
power needs to be produced, pollution from power plants
decreases. Car-pooling, using public transportation, and
walking reduce the pollutants that come from vehicles. The
sum total of all of these individual actions can be very great
indeed.
     The more informed people are about acid rain and
other environmental problems, the more they can do to make
the earth a cleaner, healthier place. Books, pamphlets, films,
and other resource materials are listed in the Bibliography of
this guide, beginning on page 51.
 24

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                                                       Acid Rain Sourcebook
                   EXPERIMENTS
      For most of the following experiments, you will need
a pH indicator, such as wide-range litmus or pH paper, a
garden soil pH testing kit, or a pH indicator that you can
make yourself (see "Making a Natural pH Indicator", Ex-
periment #3). These pH indicators contain a chemical that
changes color when it comes in contact with acids or
bases. For example, litmus and pH paper turn red in
strong acids and blue in strong bases. Because only a few
pH indicators measure pH over a wide range of pH values,
you will need to find out the pH range of the indicator you
use. Typically, the color chart provided with each pH indi-
cator kit will show the pH range of that indicator. Color pH
indicators provide only an approximate measure of the pH,
or the strength of the acid or base. They are not as accu-
rate as the expensive instruments scientists use to meas-
ure pH, but they are adequate for the following experi-
ments.
   List of Experiments
1, Measuring pH
2, Determining pH of Common
3. MaklogaMaturaipHindicator
4 Measuring tfie pHo* NatoralWatef
5. Measuring Soil pH
>$
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Acid Rain Sourcebook
 Experiment Supplies
 For the names of supply companias,
 you can consult the yeJJow pages of
 your telephone directory under a
 heading such as "laboratory
 Equipment and supplies.' If your local
 directory does not have such a
 from a larger city, telephone
 '&w$8fc» are available ?ft nwny
Measuring Liquids with a Garden Soil pH Test Kit
      Soil pH test kits are designed to measure the pH of
soil, but they may also be used to measure the pH of liq-
uids, such as water and water mixtures. Most of these kits
contain a test solution (liquid pH indicator), color chart,
and clear plastic test container, such as a test tube.
   To measure pH, pour 1 /4 teaspoon of the mixture you
want to test into the test container, and add  1 /4 teaspoon
of the test solution provided in the kit. Cover the container
and shake once or twice to mix, or stir if necessary.
Compare with the color chart provided with the kit and
write down the result.
                         Tips
                            Except for wide-range pH test paper, all the materials
                            called for in these experiments, including distilled water
                            and borax, can be obtained at grocery stores or from
                            local lawn and garden stores or nurseries.
                            Wide-range pH test paper is inexpensive, but not easily
                            obtained. A school science laboratory will probably have
                            it or can order it, or you may order it through a biologi-
                            cal supply company.  Litmus pH paper is usually in-
                            cluded in chemical sets sold at toy stores for children
                            over 8 years old.
                            Inexpensive garden soil pH testing kits are available at
                            most lawn and garden stores  or nurseries. These testing
                            kits usually contain a pH indicator solution that covers
                            a range of at least pH 4 to 10, which is wide enough for
 26

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                                                      Acid Rain Sourcebook
   most of the following experiments.
•  You may substitute baking soda for household ammonia
   in the experiments. If you do, be sure to stir well
   because baking soda does not dissolve easily in water
   unless heated. The pH of undissolved baking soda will
   not be the same as dissolved baking soda.
»  You may substitute fresh-squeezed lemon juice for white
   vinegar. Lemon juice is slightly more acidic than the
   vinegar sold in grocery stores. White vinegar is preferred
   over cider vinegar or lemon juice because it is colorless
   and relatively free of impurities.
•  Use clean, dry containers and utensils.
                                                                           27

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Acid Rain Sourcebook
                       Safety in the Laboratory
                       A science or chemistry laboratory can and should be a safe
                       place to perform experiments. Accidents can be prevented if
                       you think about what you are doing at all times, use good
                       judgement, observe safety rules, and follow directions.
                       Each experiment will include comments to alert you to
                       probable hazards, including how to protect yourself and
                       others against injury.

                       •  Eye protection (goggles or safety glasses) must be worn
                          when working on experiments. Make a habit of putting
                          them on before the experiment begins and keeping them
                          on until all clean-up is finished.
                       •  Do not eat, drink, or smoke while in the laboratory.
                       •  Do not taste  any chemical.
                       •  Long-sleeved shirts and leather-topped shoes must be
                          worn at all times.
                       •  Long hair must be tied back, so it will not fall into
                          chemicals  or flames.
                       •  Do not work  alone; work with an adult.
                       •  Never perform any unauthorized experiment.
                       •  All glassware must be washed and cleaned. Wipe all
                          counter surfaces  and hands with soap and water.
                       •  All experiments that produce or use chemicals that
                          release poisonous, harmful,  or objectionable fumes or
                          vapors must be done in a well-ventilated area.
                       •  Never point the open end of a test tube at yourself or
                          another person.
                       •  If you want to smell a substance, do not hold it directly
                          to your nose. Instead, hold the container a few
28

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                                                      Acid Rain Sourcebook
   centimeters away and use your hand to fan vapors
   toward you.
•  When diluting acids, always add the acid to the water;
   never water to acid. Add the acid slowly.
•  Flush with large quantities of water when disposing of
   liquid chemicals or solutions in the sink.
•  If you spill any acid or base material on you, wash the
   exposed area with large amounts of cold water. If skin
   becomes irritated, see a physician.


Recording Observations
   Writing your observations on these experiments will help
you to keep better track of the progress of the experiment.
Written data are not forgotten. Record keeping can be very
simple and still be a help. These hints can help you organ-
ize and record your thoughts.
•  Use a bound notebook so that pages are not lost.
•  Write complete sentences for all written entries.
•  Use drawings as needed.
•  Date each entry (even drawings).
•  Use the title of the experiment as your first entry.
•  When your observation entries have been completed,
   write your answers to the questions that follow each ex-
   periment.
•  Write your own thoughts about the experiment as the
   conclusion.
                                                                           29

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Acid Rain Sourcebook
 Materials:
 •   pH paper and color chart (pf-J
    range 3 to 12) or garden soit
    grocery stores and drag stores)
    white vinegar
    household amm onia {or baking
    soda)     :
    3 small, clear cwps or glasses
    3 stirrtng spoons
    measuring cups and epoons
    (t/2cup, 1/4 and 1/2 teaspoon)
                  EXPERIMENTS!
                    Measuring pH

This experiment will illustrate how to measure the approxi-
mate pH of chemicals in water using a pH indicator. A pH
indicator is a chemical that changes color when it comes in
contact with acids or bases.

Instructions:

1. Rinse each cup with distilled water, shake out excess
   water, and label one cup vinegar, the second cup ammo-
   nia, and the third cup water.
2. Pour 1/2 cup distilled water into each of the 3 cups.
3. Add 1/2 teaspoon white vinegar to the vinegar cup and
   stir with a clean spoon.
4. Add 1 /2 teaspoon ammonia to the ammonia cup and
   stir with a clean spoon.
5. Do not add anything to the water cup.
6. Dip an unused, clean strip of pH paper in the vinegar
   cup for about 2 seconds and immediately compare with
   the color chart. Write down the approximate pH value
   and set the cup aside. (If using a garden soil pH tester
   kit, pour 1/4 teaspoon of the contents of the vinegar
   cup into the test container, and add 1/4 teaspoon of the
   test solution.) Cover the test tube and shake once or
   twice to mix, or stir if necessary. Compare with the color
   chart provided in the kit, and  record the result.
30

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                                                                Acid Rain Sourcebook
7. Dip an unused, clean strip of pH paper in the ammonia
   cup for about 2 seconds and immediately compare with
   the color chart. Write down the approximate pH value
   and set the cup aside. (If using a garden soil pH tester
   kit, repeat the same process in step 6 using the con-
   tents of the ammonia cup instead of the vinegar cup.)
8. Dip an unused, clean strip of pH paper into the water
   cup for about 2 seconds and immediately compare with
   the color chart. Write down the approximate pH value.
   (If using a garden soil pH tester kit, repeat the same
   process above using the contents of the water cup in-
   stead of the ammonia cup.)
Questions:
1,. Is vinegar an acid or a base.?-:
   (Vinegar is an acid, and in this
   experiment it will display a pH of
   about 4. Vinegar at pH 4 turns pH
   paper yeflQW andrna$ lo&er pH;:;
   indicatorsred.)
Z,  Is ammonia an aolef or a bass?
   (Ammonia is a base and in this
   experiment it will display a pH of
   about 10. Bases turn mostpH
   indicatorabiue.)
3.  Were you surprised to find that the
   distilled water did not have a
   neutral f>H?
   (Pure distilled wafer would have
   fc^ec" neutral, but parediistille:d
   water fs not easily obtained
   because carbon dioxide m foe air
   around us mixes, or dissolves, in
   the water, fliaking K somewhat
   acidic. The pH of distilled water is
   between 5.6 and 7. To neutralize
   distilled water, add about 1/8 tea-
   $ppon baking $0da, Pr a dreg of
                                                                     pH of tie water wifli a ptt
                                                                     inoloator,. I
                                                                     repeat the process until pH ? is
                                                                     reached. Should you accidentally
                                                                     add too .rnueh.baklng soda or ani-
                                                                     monia, either start over or add a.
                                                                     drop or two of vinegar, stir, and
                                                                                         31

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Acid Rain Sourcebook
 Materials:
 »   pH pspersnd cgfor chart fangs
    pH £jo 12J or garden soil ptt
   : testing Mt
 »   & fresh whole frutte (lemon,
    time, orange, of melon)
 •   3 beverages (cola, carbonated
 ••••'•••  non-cote, milk) •••-.  .    7.
 •f. ••.•  1/8 teaspoon borax	>••'  ;.'"••••
 •j;  distilled.water|y""' ..    :.;.
 '• .. ftieasurirtgspoons(t/4and:|.... •
 "'••'  Wteaspoons).    .  .:.'•"  :
 •   4 srnall, clear 
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                                                              Acid Rain Sourcebook
5. Pour each liquid into an appropriately labeled cup.
6. Dip an unused strip of pH paper into the cola, compare
   with the color chart, and record the result. Repeat the
   same process for the remaining beverages. Be sure to
   use a clean, unused strip of pH paper for each one. (If
   using a garden soil pH tester kit, pour 1/4 teaspoon of
   cola into the test container, and add 1/4 teaspoon of the
   test solution. Tightly press your finger over the top of
   the test container and shake once or twice to mix, or stir
   if necessary. Compare with the color chart provided in
   the kit, and record the result.)
7. Add 1/8 teaspoon borax to 1/4 cup distilled water and
   stir for about 2 minutes. Dip an unused strip of pH
   paper in the borax mixture,  compare with the color
   chart,  and record the result.  (If using a garden soil pH
   tester kit, pour 1/4 teaspoon of the borax/water mix-
   ture into the test container,  and add 1/4 teaspoon of
   the test solution. Tightly press your finger over the top
   of the test container and gently shake, or stir if neces-
   sary. Compare with the  color chart provided in the kit,
   and record the result.)
Questions:
t.  Are temons, limes, and oranges
   acids or bases?
   {These fruits all contain acids
   and taste sour. Lemons and
   : Jfnrie> have pM values near %
   acfd.ic.tHah temorts ahd ttfnes,
   but your pH indicator may not Jw
 .  difference*)    ..... , ...... : ..... :. '
£.... Are colas and non-colas acids
 ':•• (TheV aw boih acidic, primarily. •
.  . became tf^y contain carbon .  :
   dlpidcte to make them fizz, and
  . carbon dioxide and water
 . .. produce carbonic acid, The pH  ;
   : of these ijeverages varies with
   . the amount of carbon dioxide
  . and other ingredients in them  ..-
   but Is usually below 4.)
3.. Was the ffliik acidic or basic?
.  . Milk can be slightly basic or
   ,$ttghdy acidic, depending on its
   .age and how it was processed
  : at the dairy,
"4*  :Wastt?eborax/waterm!xture  I
  , acidic or.basic?
...... {Borax contains a strong base . .
:  . • and wi turn most pH indicators
  ! blue, the appro ximatepH of the
.   feoraxAwater mixture is 11. its
: ...... . ; alkaline properties make it an. . . ;. .
                                                                  ..-is. why., gome people us* ft to
                                                                ;'•',  wash clothes,).   :     ;-
                                                                                       33

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Acid Rain Sourcebook
 Materials:
 *  stainless steal or enamel pan or
    : microwave casserole dtetv
 »  1 quart water
    stove, microwave, or hotptate
 •  white vfnegar
 •  ammonia or baking soda
 »  dear, non-cola beverage
 *  3 glass cy p$ (prdfer ab) y ofear }
 *  $ dean teaspoons for stirring
 *  measudngenp(J/4cwp)
 *  notebook and pertcif
                 EXPERIMENT #3
           Making a Natural pH Indicator

   In this experiment you will make your own pH indicator
from red cabbage. Red cabbage contains a chemical that
turns from its natural deep purple color to red in acids and
blue in bases. Litmus paper, another natural pH indicator,
also turns red in acids and blue in bases. The red cabbage
pH indicator can be obtained by boiling the cabbage.

Instructions:
                         1. Boil cabbage in a covered pan for 30 minutes or micro-
                           wave for 10 minutes. (Don't let water boil away.)
                        2. Let cool before removing the cabbage.
                        3. Pour about 1/4 cup of cabbage juice into each cup.
                        4. Add 1/2 teaspoon ammonia or baking soda to one cup
                           and stir with a clean spoon.
                        5. Add 1/2 teaspoon vinegar to second cup, stir with a
                           clean spoon.
                        6. Add about 1 teaspoon clear non-cola to the last cup and
                           stir with a clean spoon.
                        7. After answering the first two questions on the next page,
                           pour the contents of the vinegar cup into the ammonia
                           cup.
34

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                                                                  Acid Rain Sourcebook
Related Experiment: Neutralizing Acids or Bases Using a
Garden Soil pH Tester Kit
   Pour 1/4 teaspoon of the contents of the vinegar cup
   into the test container, and add 1/4 teaspoon of the test
   solution. Seal the top of the test container with your fin-
   ger, shake once or twice, or stir if necessary, and com-
   pare with the color chart. Then pour about 1/4 tea-
   spoon of the contents of the ammonia cup into the test
   container. Mix it and compare with the color chart.
   What happens to the pH? What would happen if you
   added more of the ammonia mixture?  (For answers: see
   questions 3 and 4.)
                                                                    Questions:
 1.  What color change took piace
  .  when you added vinegar to the. ;
.:• :.• cabbage juice? Why? ,      '
 ••:,  ;i (The vinegar and cabbage juice .
 5 .  mixtures should change from
 :   deep purple to red, indicating
    that vinegar is an acjd.)
 2.  Ofd the ammonia torn Sue
    cabbage juice pH indicator red or
 •;••  blue? Why?            •••••
  ; .  (The ammonia and cabbage   ;
    juice mixture should change from
    deep purple to blue, because
    ammonia, like baKing soda, is a .
  :  base, which reacts ebemtaally  .
    with the pH indicator, turning it \
    blue.) '.;
 3,  What happens to the coior tf you
 '<   pour the contents of the vinegar
: ; . cup into the,ammonla cup?
 :   
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Acid Rain Sourcebook
 Materials:
 :.• ..'"•". f>H paper and color chart grange
 • : ::. ijrgaKfen sol pH testing kit
 ••» ,:'""' )
                   EXPERIMENT #4
          Measuring the pH of Natural Water

   In this experiment you will measure the pH of natural
water located near your home or school.

 Instructions:


 1. Locate a stream, river, lake, or pond. Go with an adult.
 2. Scoop some of the surface water into a cup.
 3. Measure the pH of the water using either pH paper or a
   garden soil pH testing kit (procedures described in the
   introduction to the experiments section) and record the
   result.

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                                                       Acid Rain Sourcebook
                 EXPERIMENT #5
                  Measuring Soil pH

   In this experiment you will collect soil and measure its
pH. Soil pH is one of several important conditions that
affect the health of plants and animals. In addition, you
will also be asked to survey the plants and animals that
live in the area where you collected the soil. Area surveys
provide information about how well plants and animals can
live under different conditions.
   For this experiment, you will need an inexpensive gar-
den soil pH test kit, which may be obtained from lawn and
garden stores or nurseries.

Instructions:

1. Pick two or three different soil locations,  such as a gar-
   den, wooded area, city park, or meadow. Ask an adult to
   go with you.
2. At each location, observe the plants and  animals living
   in or rooted on these soils, especially those that are in
   greatest numbers. Write down as much as you can
   about what you find. Dig down about 2 inches, scoop
   out 2 cups of soil, and seal it in a plastic bag for later
   use. Label each plastic bag. Be sure to clean your dig-
   ging tool after collecting soil samples at each location.
3. Measure the pH of each soil sample following the direc-
Moterials:
   gard
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Acid Rain Sourcebook
  Questions:
 ' 1 <  Were there any fatg
     differences between the plant
     artdarttmal life at each
     location? (Some types 
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                                                        Acid Rain Sourcebook
                  EXPERIMENT #6
                     Soil Buffering

   Soil sometimes contains substances, like limestone, that
buffer acids or bases. Some salts in soil may also act as
buffers. In this experiment you will find out if soil from
your lawn, garden, or school can buffer acids. You will
observe the pH change of an acid mixture poured over soil
in a filter. If the water collected from the filter is less acidic
than the original mixture, then the soil is buffering some of
the acid. If it does not change, then the soil may not be
capable of buffering acids. Since the buffering capability of
soils differs, you may want to do this experiment with
several different soil types including those collected for the
"Soil pH" experiment.

Instructions:
Materials:
   pHj»pwancf color oharMpH
   or garden sott ptf test kit
   about 2 cups 01 soil from a
   garden, wooded areajawn.or
   (school yard
   distilled water
   stirring spoon
   large funnet
   papercup
   notebook and pencit
1. Pour 1 teaspoon of vinegar into 2 cups of distilled water,
   stir well, and check the pH with either pH paper or a
   garden soil pH testing kit (procedures described in the
   introduction to the experiments section). The pH  of the
   vinegar/water mixture should be about 4. If it is below
   that, add a sprinkle of baking soda, stir well, and re-
   check the pH; but if it is above pH 4,  add a drop or two
   of vinegar and again recheck the pH.
2. Put 1 coffee filter into the funnel, and fill the filter with
   soil from one location. Do not pack the soil down.
                                                                             39

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Acid Rain Sourcebook
  Questions:
  •i; :, Did the pttof the collected
  "...  water stay the same as the '; "i •';
     original mixture, increase, or :
     decrease?    ..•"•" ,-:/ .. •••" y.:
  ..:.;.' (If tht pH stayed Jhg .same'; jfj^'
 ,;:"'  soil did not puffer the acid, .>•
  /r: Each pH value abbve 4  : . .. i
     indicates that the soil burred :*;
     increasing amountsKjf the acid
     Even soil capable of buffering
     acids can be overpowered 8
     enough add is added. As more
     acid is added to the soil the :
     and the water from the fitter •'" .. ,
     becomes more acidic,)      ,

  2.  What can you add to the sol) to
     increase its buffering
     capability?
     (Limestone can be added, but
     the limestone to work into the
     soil.) '•   :• •"   '.•••".•/
3. Hold the filter over a paper cup and slowly pour the
   vinegar/water mixture over the soil until some water
   collects in the paper cup (the filter may clog quickly, but
   you need only a small amount of water).
4. Check the pH of the collected water using either pH
   paper or a garden soil pH testing kit and record the
   results (procedures described in the introduction to the
   experiments section).
5. Repeat the experiment with other soil samples, using a
   new coffee filter for each sample.
40

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                                                       Acid Rain Sourcebook
Materials:
                 EXPERIMENT #7
 Observing Influence of Acid Rain on Plant Growth

   Acid rain most often damages plants by washing away
nutrients and by poisoning the plants with toxic metals. It
can, however, have direct effects on plants as well. In this
experiment you will observe one of the direct effects of acid
water on plant growth. The experiment will take about 2
weeks.
   white vinegar
   measwringcupe
   stirring spoon
   2cuttingsofaphilodendron
   pfant(t teaf artcf small amount
   of stem)
   2 cuttings of a begonia or
   coteus plant (1 leaf and small
Instructions:

1.  Pour 1 teaspoon of vinegar into 2 cups of distilled
    water, stir well, and check the pH with either pH paper
    or a garden soil pH testing kit (procedures described in
    the introduction to the experiments section). The pH of
    the vinegar/water mixture should be about 4. If it is
    below pH 4, add a sprinkle of baking soda, or a drop of
    ammonia, stir well, and recheck the pH. If it is above
    pH 4, add a drop or two of vinegar and again recheck
    thepH.
2.  Measure the pH of the distilled water using either pH
    paper or a garden soil pH testing kit. If the pH is below
    7, add about  1/8 teaspoon baking soda, or a drop of
    ammonia, stir well, and check the pH of the water with
    the pH indicator. If the water is still acidic, repeat the
                                                                            41

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Acid Rain Sourcebook
 Question:
    fastest root growth, those in
    distilled water or those In ackf :
    water?
    water should grow tester than
    plants grown in acid waser<
    Acid water, tike add rain, can
    directly damage plants and
    slow or stop new growth.^ :
    process until pH 7 is reached. Should you accidentally
    add too much baking soda or ammonia, either start
    over again or add a drop or two of vinegar, stir, and
    recheck the pH.
3.  Put one of the following labels on each cup or jar:
        water philodendron
        acid philodendron
        water begonia (or coleus)
        acid begonia (or coleus)
4.  Pour about a cup of distilled water into the water-
    philodendron and water-begonia cups.
5.  Pour about a cup of the vinegar/water mixture into the
    acid-philodendron and acid-begonia cups.
6.  Put one philodendron cutting into each philodendron-
    labeled cup, covering the stem and part of the leaf with
    the liquid.
7.  Put one begonia cutting into each begonia-labeled cup,
    covering the stem  and part of the leaf with the liquid.
8.  Set the cups where they are not likely to be spilled and
    where they will receive some daylight.
9.  About every 2 days, check to  be sure that the plant
    cuttings are still in the water or vinegar/water. You
    may need to add more liquid if the cups become dry.
10. After  1 week, compare the new root growth of each
    plant in distilled water with the new root growth of its
    corresponding plant in acid water. Record the results.
11. After 2 weeks, again observe the plant cuttings for new
    root growth, and record the results.
42

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                                                       Acid Rain Sourcebook
                 EXPERIMENT #8
   Observing Buffers in Lakes, Ponds, and Streams

   In this experiment you will observe the effects of lime-
stone on the acidity of water. Some areas of the nation
have a lot of limestone in lake bottoms and in soil, which
helps neutralize the effects of acid rain. Crushed limestone
is sometimes added to lakes, ponds, and other aquatic
areas to help neutralize the effects of acid rain, thus pre-
serving important aquatic systems until the source of acid
rain can be reduced. Crushed limestone is easily obtained
from local lawn and garden stores or nurseries.
Materials:
   pH paper and .color chart
   (range pH 2 to 7)
   or garden soil pH testing kit
   white vinegar
   distilled water
   measuring cup and spoon
   £ stirring *paons
   112 cup crushed hydrated
   limestone or spray limestone
   £ cereal *x>wt& (about 2 ei»p
   size)
   plastic.wrap  :.;• .    .•
   notebook and. pencil  .'"' • ','
Instructions:

1. Label one bowl vinegar; the other one vinegar plus lime-
   stone.
2. Pour 1/4 cup crushed limestone into one bowl.
3. Pour 1 teaspoon of vinegar into 2 cups of distilled water,
   stir well, and check the pH with either pH paper or a
   garden soil pH testing kit (procedures described in the
   introduction to the experiments section). The pH of the
   vinegar/water mixture should be about 4. If it is below
   pH 4, add a sprinkle of baking soda, stir well, and re-
   check the pH; but if it is above pH 4, add a drop or two
   of vinegar and again recheck the pH.
                                                                             43

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Acid Rain Sourcebook
 Questions:
 ' 1.."' Did the pH of the vinegar/water
   .  mixture over &» limestone1 '"•>.;;;;'
 •   - become rnore or less acidic  , •
     during the 6-day period? viyhy?;;
 ",.   (The water mixtur e should 'havex
  :   bewme less aeitfc, changing/
 .   ... from about j>H 4 to $$ rrtgch'l*;.
     pHe.ctependinganthewatei' ;
     content ol the. limestone yow: -x.
  .  •••used!	"v1  .  '	:''"":.;:;.:.:
 2.   Does crushed limestone buffer
     Sieaeld?          ••:,., •••x
     (Yea, by neutralizing tt.) •./••'•  .
 9.   Did the pH of the vinegar/water
     mixture in thia otttarbowt
     (without limestone) change:  .•;:
     dgring the 6-day period?   : ,
     (The pH of the bowl without. ;...
     limestone should not have
     changed.)            ;...-.-
4. Pour about 1 cup of the vinegar/water mixture over the
   limestone in the cereal bowl and stir with a clean, dry
   spoon.
5. Pour the remaining vinegar/water mixture into the other
   cereal bowl.
6. Check the pH of the vinegar/water mixture over the
   limestone and record it.
7. Cover each bowl with plastic wrap to prevent evapora-
   tion.
8. Every day for 6 days, stir the contents of each bowl with
   a clean, dry spoon and about 4 or more hours later
   (after the limestone has settled), test the pH of the water
   mixture in each bowl and record the result.
 44

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                                                       Acid Rain Sourcebook
                 EXPERIMENT #9
          Looking at Acid Effects on Metals

  When acids and metals come in contact with each other,
the metal is gradually dissolved away in a chemical reac-
tion. In this experiment you will observe this reaction for
yourself, but you will need patience. The chemical effect of
acids on metals may take at least five days for the human
eye to see, even though the reaction starts as soon as the
acid contacts the metal.

Instructions:
Materials:
   $>n papsr and color chart {pH
   range 2 to 7)
   or garden soil pH testing kit
   ; 2 small, clear glasses
   {nownefaf}
   2 clean copper parirttes (use
   permiesfninted
   squeezed lemon juice
   distilled water
   plastfowrap
1. Label one glass water and the other vinegar or lemon
   juice depending on which acid you use.
2. Place one penny in each glass. Be sure to use pennies
   minted before 1983 because pennies minted after that
   time have a different chemical composition.
3. Barely cover one of the pennies with either vinegar or
   lemon juice.
4. Dip a strip of pH paper into the vinegar, or lemon juice,
   for about 2 seconds, compare with the color chart, and
   record the result. Or use a garden soil pH test kit (pro-
   cedures described in the introduction to the experi-
   ments section).
5. Add enough distilled water to the glass labeled water to
   barely cover the other penny.
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Acid Rain Sourcebook
  Questions:
 :;' 1,.; '•:f: What change, if any, took pj$ce
   •  in the water glass after 5 days?
 J ;.;;(There should be n0ehang&4
 %.•  Vi^at change, .if any, *?£>k
 .-;;&.. place5i flievinegar
 ;•!•!> •
 ':•'• ,:.:;:! (The liquid should be bluish-
    jgreen, The bluish-green
   H substance irithe vinegar, or
 •:;."" -"lemon juice, comes from the
    : copper in )he penny Jt is a
 /'" ..byproduct of the chemical
   : ,,, reaction in which the acid lit :
   ..../""the vinegar, Drlerppnjuiqe,-
 ;    ytey gradually eats away ^e
  3> ..;: Wflienyou rinsed off the
  .   pennies, where you surprised
  .v • •  titet they both looked abool the
     same as they did at the
  • •'•" .. beginning of the experiment
  •   (assuming ydu used clean
  ,.:..• pennies)?
  ";   \Cnie chemical rpaction
     ooppef penny is $a slow that
     ,yqy cannot see any difference
    ; in the shape 6l ttie metal injyst
    :: 5 days^ at least notwith your;
     eye alone. You may see some
    : .changes after about 2 weeks. ..
     aspeciatty at the edge of the
6.   Dip a strip of pH paper into the distilled water for
     about 2 seconds and compare with the color chart. Or
     use a garden soil pH test kit (procedures described in
     the introduction to the experiments section). If the pH
     is below 6, add a tiny amount (less than  1/8 teaspoon)
     of baking soda, or a drop of ammonia, and recheck the
     pH. Repeat this process until the pH is between 6 and
     7. Record the pH of the water.
7.   Seal the top of each glass with plastic wrap to prevent
     evaporation.
8.   Place in a safe, dry place for about 5 days.
9.   After about 5 days, observe the changes that occurred
     in each glass.
10.  At the end of the experiment, wash off the pennies
     with water, and pour the contents of the glasses down
     the sink (do not drink).
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                                                      Acid Rain Sourcebook
                    ACTIVITIES

• Classroom: Collect acid rain and air pollution cartoons
from newspapers and magazines. Display and discuss
them.

• Classroom: Imagine that you are all scientists. Think
about a research project to investigate some aspect of acid
rain—how it forms, the damage it does, etc. Write your
ideas on the board. Discuss the questions you would ask
and the steps you would take to do the research. If pos-
sible, invite a local research scientist to the classroom to
review your project and comment on it.

• Small groups or individuals: Write, produce, and direct a
special segment for a T.V. "weather special" on the effect of
weather patterns on the travel of acid rain over large dis-
tances. Contact the weather bureau or a local television
station's weather department to ask about the wind pat-
terns in your area.

• Class Trip: Visit a nearby science center or museum of
science. Request information on educational programs for
acid rain. Look for exhibits that relate to the causes and
effects of acid rain and how acid rain travels (weather).
Note: If there is no such museum nearby, write to the near-
est one and request information on educational programs
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Acid Rain Sourcebook
                       or their exhibits that deal with acid rain and its effects.

                       • Individual students: Design a word-find puzzle using the
                       words in the GLOSSARY of this guide.

                       • Individuals: Contact a local NATURAL RESOURCE
                       SPECIALIST from your local zoo or park and ask that per-
                       son to tell you about the impact, if any, of both acid rain
                       and dry deposition in the lakes, forests, or other natural
                       resources in your area. (An alternative to this would be for
                       the class to invite a specialist to come and speak on this
                       topic.) Write down what you have learned in a report to be
                       given to the teacher or read to the class.

                       • Classroom: Role playing. Each of you takes the role of an
                       "interested party" (for example, a fish, bird, coal miner,
                       factory  owner, smokestack, fisherman, farmer, stream,
                       lake,  tree, or forester) in a group discussion on acid rain.
                       Talk about the effects acid rain has on your character and
                       then present arguments for or against laws to control acid
                       rain.

                       • Field Trip: Visit a local cemetery and observe the wearing
                       away of the headstones or other grave markers over time.
                       Military cemeteries use limestone markers which are more
                       easily affected by acid rain than the granite markers in
                       some private cemeteries. Can you tell by the dates on the
 48

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                                                      Acid Rain Sourcebook
marker stones and the condition of the stones which ones
acid rain may have damaged? Remember that these materi-
als would naturally deteriorate when exposed to the
weather and rain (even clean rain). Acid rain would acceler-
ate this damage.

• Individual research: Contact your local power company.
Many power companies use more than one source of power
to make enough electricity for the community. Some also
buy electricity from other power companies. Ask the power
company which is its primary source (hydroelectric, nu-
clear, gas, oil, coal, other) and what other sources it uses.
If they can tell you, find out what percent of their output is
generated by each source. If your company buys from other
companies ask if they know what source generates that
company's electricity. Write down your results in a report
to be read to the class.

• Class or individual: Locate or list energy efficient build-
ings in your community. Contact a local architect or an
architecture department in a local college or university and
invite an architect to visit your classroom to describe how
homes, schools, and office buildings can use energy more
efficiently.

• Individual: Find out if your drinking water is being
treated for acidity. Call or visit the water company. First
                                                                           49

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Acid Rain Sourcebook
                        determine the source of your water—well, lake, or river. If
                        you have a private source of water such as your own well,
                        ask your parents if the water is treated, and if so, how it is
                        treated. When talking to a water company, usually a city or
                        county water authority, ask if and how they treat the water
                        for acidity. Ask them to tell you the pH of the water before
                        it is treated and the pH after it is treated. Is it completely
                        neutralized? Write down their answers in a report to give to
                        the teacher or read to the class.
 50

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                                                    Acid Rain Sourcebook
                 BIBLIOGRAPHY

Readings

Acid Rain
Boyle, Robert H.; Boyle, Alexander R.
New York: Schocken Books, 1983

Acid Rain
Gay, Kathlyn
New York: Franklin Watts, 1983
(Available from: New Order Department, Franklin Watts,
Sherman Turnpike, Danbury, CT06816. $11.50--quantity
discount available)

Acid Rain
McCormick, John
New York: Gloucester Press, 1986

Acid Rain: A Plague Upon the Waters
Ostmann, Robert
Minneapolis, MN: Dillon Press, 1982

Acid Rain: A Sourcebook for Young People
Miller, Christina G.; Berry, Louise A.
New York: Julian Messner, 1986

Acid Rain Kids Handbook
Washington, DC: National Geographic Society, 1988

Acid Rain Reader
Stubbs, Harriet S.; Klinkhammer, Mary Lou, and Knittig,
Marsha
Raleigh, NC:  Acid Rain Foundation, 1989

Acid Rain Study Guide
Hunger, Carolyn; Pfeifer, David; Hallowell, Anne
Wisconsin Department of Natural Resources
(Available from Wisconsin Department of Natural
Resources, Box 7921, Madison, WI 53707)

For Crying Out Cloud: A Study of Acid Rain
Coyne, Martha
Minneapolis, MN: Tasa Publishing Co., 1981
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Acid Rain Sourcebook
                       Going Sour: Science and Politics of Acid Rain.
                       Gould, Roy
                       Cambridge, MA: Birkhauser Boston, Inc., 1985

                       "How Scientists Are Tracking Acid Rain"
                       Gannon, Robert
                       Popular Science, August 1984, p. 67-71

                       Rain of Troubles
                       Pringle, Laurence
                       New York: MacMillan, 1988

                       Troubled Skies, Troubled Waters; The Story of Acid Rain
                       Luoma, Jon R.
                       New York: Viking Press, 1984
                       Audiovisuals

                       Acid Rain (software for Apple Computers)
                       (Available from: Diversified Educational Enterprises, 725
                       Main St., Lafayette, IN 47901)

                       "Acid Rain: New Bad News" (video, 58 minutes)
                       NOVA/WGBH Educational Foundation
                       (Available from U. of Michigan Film & Video Library, 313/
                       764-5360. Rental fee $20.50)

                       Air Pollution (Software for Apple or TRS-80 Model III & IV)
                       (Available from: Educational Materials and Equipment Co.,
                       PO Box 17, Pelham, NY 10803)

                       "Decision: Energy for the Future" (film or video, 11
                       minutes)
                       Earth Metabolic Design
                       (Available from: Bullfrog Films, 800/543-FROG or 215/
                       779-8226. Purchase price for 16mm $250, video $65;
                       rental fee $25)

                       "For the Long Run" (video, 20 minutes)
                       National Park Service
                       (Available from: National Park Foundation, P.O. Box 57473,
                       Washington, DC 20037, 202/785-4500. Purchase price
                       $65; call for catalog).
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                                                     Acid Rain Sourcebook
"Into Deep Waters" (video, 26 minutes)
Bellamy, David
(Available from: Bullfrog Films, 800/543-FROG or 215/
779-8226. Purchase price for 1/2" video $250, 3/4" $265;
rental fee $50)

"Problems of Conservation: Air" (film, 15 minutes)
NOVA/Encyclopaedia Britannlca Educational Corporation
(Available from: U. of Michigan Film or Video Library, 313/
764-5360. Rental fee $15.40)

HRunning Out of Steam" (video, 26 minutes)
(Available from: Bullfrog Films, 800/543-FROG or 215/
779-8226. Purchase price for 1/2" video $250, 3/4" $265;
rental fee $50)

The Sky's the Limit" (film or video, 23 minutes)
Ken White
(Available from; U. of California Extension Media Center,
415/642-0460. Purchase price for 16mm film $450, video
$310; rental fee $40)

"Still Waters" (film, 57 minutes)
NOVA
(Available from U. of Michigan Film or Video Library, 313/
764-5360 or 800/999-0424. Rental fee $35.35)

"Water: A Precious Resource" (film or video, 23 minutes)
(Available from:  National Geographic Society Educational
Services, 800/368-2728. Purchase price for video $69.95,
film $240)
                                                                           53

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                                                     Acid Rain Sourcebook
                       GLOSSARY

Acid Any of a large group of chemicals with a pH less than 7.
Examples are battery acid, lemon juice, and vinegar.

Acidic Describes an acid. For example, lemon juice is acidic.

Acid Rain Wet precipitation that has become acidic by contact with
air pollution. Other forms of precipitation, such as snow and fog,
are also often included in the term acid rain or acid deposition.

Alkaline Describes a substance such as baking soda, milk of
magnesia, or ammonia, that can dissolve in water and neutralize
acids.

Aquatic  Growing or living in water.

Atmosphere  The air or gases that surround a planetary body such
as the earth.

Base Any of a large group of chemicals with a pH greater than 7.
Examples are ammonia and baking soda dissolved in water.

Basic Describes a base.  For example, alkaline materials are basic.

Buffer A substance, such as soil, bedrock, or water, capable of
neutralizing either acids or bases.

Buffering Capacity  The ability of a substance to resist changes in
pH when acids or bases are added.

Carbon Dioxide  A colorless, odorless gas made of the elements
carbon and oxygen. Animals exhale carbon dioxide and automobile
exhaust contains carbon dioxide.

Catalytic Converter A device that burns off pollution from exhaust

                                                                          55

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Acid Rain Sourcebook
               gases. Commonly used in automobiles and required on all cars sold
               in the United States since 1973.

               Chemical A substance made up of elements combined together.

               Condense To change from gas or vapor to liquid form.

               Dry Deposition The falling of small particles and gases to the earth
               without rain or snow.

               Ecosystem  The relationships among animals and plants and their
               environment in a particular area.

               Energy The power to do physical work. Electricity and heat are
               energy sources.

               Environment The combination of all conditions surrounding living
               things.

               Fossil Fuels Oil, natural gas, coal, and similar products that are
               taken from the earth and used for energy. Fossil fuels were made in
               nature from  ancient plants and animals.

               Habitat The place where a plant or animal lives and grows, such as
               a forest, lake, or stream.

               Hydroelectric Power The production of electrical energy using
               water power.

               Hydrologic Cycle The movement of water from the atmosphere to
               the surface of the land, soil, and plants and back again to the
               atmosphere.

               Limestone A rock that is made from ancient shells and coral.
               Limestone contains calcium carbonate and is a base.

               Liming Adding crushed limestone to lakes, streams, or other

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                                                      Acid Rain Sourcebook
bodies of water is called liming and it raises the pH of the water.

Litmus Paper Paper coated with a chemical coloring obtained from
lichens that turns red in acidic water and blue in basic water. It is
used as an acid-base indicator.

Natural Resources All the parts of the earth that are not human-
made and that people use, like fish, trees, minerals, lakes, or rivers.

Natural Resources Specialist A person who knows a great deal
about animals and plants and where they live—for example,
naturalist, forester, forest ranger, etc.

Neutral A substance that is neither an acid nor a base and has a
pH of 7. Neutral substances can be created by combining acids and
bases.

Neutralize To combine acids and bases to make a neutral
substance or solution.  For example, acidic water can be neutralized
by adding a base, such as limestone.

Nitric Acid An acid that can be produced in the atmosphere from
nitrogen oxide.

Nitrogen Oxides A family of gases made up of the elements
nitrogen and oxygen commonly made by burning fossil fuels.

Nuclear Power  Energy that comes from the center (nucleus)  of an
atom.

Ozidants  Chemicals that supply oxygen to other chemicals when
they are combined in a chemical reaction.

Particles  Tiny solid fragments that float in the air, such as dust.

pH Scale  The range of units that indicate whether a substance is
acidic, basic, or neutral. The pH scale ranges from 0 to 14; a pH of
                                                                           57

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Acid Rain Sourcebook
                7 is neutral, lower than 7 is acidic, and greater than 7 is basic.

                pH Paper Paper that changes color to show the pH of a substance.

                Photosynthesis The process that plants use to convert sunlight to
                energy to live and grow.

                Plankton Tiny organisms that float or drift in water and serve as a
                food source for larger animals such as fish.

                Precipitation Mist, sleet, rain, hail, or snow falling to the earth.

                Pollutant A harmful chemical or other unwanted substance
                released into the environment by human activity.

                Pollution Chemicals or other substances that are harmful to or
                unwanted in the environment.

                Reactive Having the tendency to chemically combine with
                something else and change its form. For example a strong acid is
                highly reactive with a strong base.

                Reservoir A place where water is collected and stored for use,
                usually in an artificial basin created by damming a river.

                Runoff Water that flows off land into lakes and streams.

                Scrubber A device that removes air pollution, mainly sulfur
                dioxide, from smokestacks.

                Solar Energy Energy that comes from the sun.

                Solution A uniform mixture formed by dissolving a substance in
                liquid.

                Sulfur Dioxide  A gas made of sulfur and oxygen that is released
                when coal is burned.
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                                                       Acid Rain Sourcebook
Sulfuric Acid An acid that can be produced in the atmosphere
from sulfur dioxide. Sulfuric acid is used in automobile batteries.

Toxic  Poisonous to some living thing.

Turbine A motor activated by water, steam, or air to produce
energy.
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                                                •fsV.S. GOVERNMENT PRINTING OFFICE: 1990 • 74H-IS9/204*6

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