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Acid Rain
Sitting in your room late at night, you listen to the gentle pittter-patter of
the rain on your window. Ahh, so soothing and relaxing. Have you ever really
wondered what the rain is really made of? Is that just water or is it acid
slowly streaming down out there? That rain you hear just might be acid rain, it
could change the way you live your life.
The commonly used terms “acid rain” and “acid precipitation” describe specific
forms of a type of pollution described generally as “acid deposition.” Harmful
gases that rise into the air mix with cloud moisture, sunlight, and oxidants.
There they chemically combine into dilute sulfuric and nitric acids, which fall
back to the earth. This is acid deposition. The major contributing pollutants
are sulfur dioxide and nitrogen oxide (Morgan, 5).
“Acid rain” is basically rainwater with a pH level lower than 5.6 (Morgan, 3).
The term pH means “potential hydrogen”. When a substance has a pH level of 7,
it is completely neutral with the same number of hydroxyl and hydrogen ions
(Pringle, 6). Acidity in the atmosphere can be changed by many natural things.
When a volcano erupts, sulfur dioxide is spewed out. Droughts produce unusually
dry soil conditions allowing dust particles to be carried upward into the air,
neutralizing the acids that may be present at the time (Pringle, 4). Acid Rain
can come in concentrations sometimes more acidic than lemon juice. These
pollutants reach the earth in rain, snow, hail, sleet, or fog. The rain at the
beginning of a shower is usually more acidic than the rain that follows. Dry
acidic particles can also fall from the atmosphere. Because wind can carry
gases and moisture for hundreds of miles, even areas far away from the source
bear the effects of acid deposition (Durham, 10). There are of course, many
things that we as humans do everyday to promote and support the continuation of
acid rain. Not intentionally, of course.
When the fossil fuel, (i.e. coal) is used, the sulfur in it mixes with Oxygen
in the air to form sulfur dioxide. The sulfur dioxide is eventually turned into
acid over a matter of days. Coal-fired power plants are the single greatest
cause of acid rain in the United States. They account for two-thirds of all
sulfur dioxide emissions in the US (Pringle 16; Morgan 75). In the mid-1980’s,
the United states alone discharged about 26 million tons of sulfur dioxide
(Bennet). For decades, the highest source for sulfur dioxide emissions was the
huge Inco, Limited, a copper and nickel smelter in Sudbury Ontario. Each year
the Sudbury plant gave off 1% of the entire world’s sulfur dioxide emissions,
including both natural and human sources (Morgan, 24).
At a staggering 1,250 ft, "Superstack" is almost as tall as the
Empire State Building. Its main purpose was to act as a giant chimney to take
all toxins higher into the atmosphere so that we humans would not have to
breathe them. The air quality around the smelter was much better and plant life
started growing back. The problem was, the sulfur dioxide was then blown
whichever the winds happened to be going. Most of the time those winds to the
sulfur dioxide across state borders and into Canada (Morgan, 27) Scientists
then used satellite photography to trace the weather patterns back to where the
sulfur dioxide originated. The acid falling back down to earth, whether it is
in dry or wet form has drastic consequences for many.
A rainstorm occurs in a forest. The summer rains wash the leaves of the
branches and fall to the forest floor below. Some of the water is absorbed into
the soil while other water run-off enters nearby streams, rivers, or lakes.
When acid rain is absorbed into the ground, it slowly poisons the tree by being
absorbed through the roots. Acidic rainwater also dissolves the nutrients and
minerals that the plants need from the soil. When acid rain is frequent, leaves
tend to lose their protective waxy coating. After a leaf loses it’s protective,
waxy coating, it becomes more susceptible to diseases. By damaging the leaves,
the plant can not produce enough food energy for it to remain healthy. Trees no
longer grow as fast as they did before. Leaves and pines needles turn brown and
fall off when they are supposed to be green in color (Phamornsuwana).
Not only plants are effected by acid rain. Animals are as well. Animals in an
aquatic biome suffer more extreme consequences than that of any other biome.
The simplest way to show the amount of damage would be in the following
record/chart. Diary of Death for aquatic life:
pH 6.5 The growth rate of brook trout slows and lake trout begin to have
trouble reproducing. Clams and snails become scarce. Acid-tolerant organisms,
such as certain rotifers and filamentous green algae, start to increase.
pH 6 Brook and rainbow trout populations start to decline. Smallmouth bass and
spotted salamanders have trouble reproducing, as do several kinds of mayflies.
Several species of clams and snails are wiped out.
pH 5.8 Tiny crustaceans called copepods die out, and some kinds of crayfish
have trouble re-growing their hard exoskeletons after they molt.
pH 5.5 Rainbow trout and some smallmouth bass population are becoming extinct.
Other trout, shiners, walleyes pike, and roach fail to reproduce and their
numbers drop. Leeches and mayfly larvae disappear.
pH 5.4 The reproduction of most crayfish is impaired.
pH 5 All but one species of crayfish are dead. As are the brook trout, walleyed
pike, and bullfrogs. Thick mats of green and blue-green algae cover the lake
bottom. Some insects in crease because few fish are left to prey on them or
because they live on the water surface. These include water boatmen and water
striders.
pH 4.8 The number of leopard frogs declines, along with populations of rooted
underwater pondweeds.
pH 4.5 Mayflies and stoneflies have all died out.
pH 4.3 Pumpkinseed sunfish population declines and northern pike have
completely disappeared.
pH 4.2 The common toad dies out. It lives on land but must lay its eggs in
ponds and lakes.
pH 4 The spring peeper, another amphibian the produces in ponds and marshes
begins to die out. All aquatic plants except those that are acid tolerant are
dead or in decline.
pH 3.5 Virtually all clams, snails, frogs, fish, and crayfish are missing from
these acidic waters.
pH 2.5 Only a few species of acid-tolerant midges and some algae and fungi are
alive.
pH 2 The water is remarkably clear, but this in not a healthy clarity. The
water is virtually sterile (Bennet).
The waters of tens of thousands of Scandinavian lakes are now unnaturally clear
due to acid rain. Hundreds of lakes in New York’s Adirondack Mountains are
sterile as well. Most lakes and streams have a pH level between 6 and 8. Some
lakes are naturally acidic even without the effects of acid rain. For example,
Little Echo Pond in New York has a pH level of 4.2. Acid rain can enter a lake
or pond by many different methods (Durham, 98). Dry particles can come down out
of the atmosphere and settle into a lake or pond. Precipitation is another
common method as well as drainage from a sewer system. Probably the most
drastic method by far would have to be spring acid shock. When acid snow melts
in the spring, the acids in the snow seep into the ground. Some run-off the
ground and into lakes (Phamornsuwana). A sudden dose of acids can have
long-lasting effects on a lake or pond.
Acid rain does not only damage the natural ecosystems, but also man-made
materials and structures. Marble, limestone, and sandstone can easily be
dissolved by acid rain. Metals, paints, textiles, and ceramic can effortlessly
be corroded. Acid rain can downgrade leather and rubber. Man-made materials
slowly deteriorate even when exposed to unpolluted rain, but acid rain helps
speed up the process (Morgan, 27). Acid rain causes carvings and monuments in
stones to lose their features. It is known to dramatically accelerate the
deterioration of buildings, including landmarks such as the Acropolis in
Athens, the Taj Mahal in India, and the Statue of Liberty in New York City
(Phamornsuwana). The repairs on building and monuments can be quite costly. In
Westminster, England, up to ten million pounds was spent necessitated on
repairs damaged by acid rain. In 1990, the United States spent thirty-five
billion dollars on paint damage. In 1985, the Cologne Cathedral cost the
Germans approximately twenty million dollars in repairs. The Roman monuments
cost the Romans about two hundred million dollars (Durham, 111).
Most importantly, acid rain can affect the health of a human being. It can harm
us through the atmosphere or through the soil from which our food is grown and
eaten from. These foods that are consumed could cause nerve damage to children,
severe brain damage, or even death (Phamornsuwana). One of the serious side
effects of acid rain on human is a respiratory problem. The sulfur dioxide and
nitrogen oxide emission gives risk to respiratory problems such as dry coughs,
asthma, headaches, eye, nose, and throat irritation (Pringle, 64). Polluted
rainfall is especially harmful for people who suffer from asthma for people who
have hard time breathing. But even healthy people can have their lungs damaged
by acid air pollutants. Acid rain can aggravate a person's ability to breathe
and may increase disease, which could lead to death (Bennet)
In conclusion, any rain with a pH level lower than 5.6 are classified as acid
rain. Acid rain is made when sulfur dioxides mix with nitrogen oxides to form
acids. The acids then can come back down out of the atmosphere in either a dry
or a wet form. Both of these have proven devastating to both aquatic animals
and forests. Billions of dollars have been spent to correct and try to fix what
acid rain had done to buildings and monuments. Acid rain also has its toll on
the health of us humans. The food you eat could be contaminated with toxins due
to acid rain, you’d never know it either.
Sources:
Bennet, Mark. “Acid Rain” 2-25-00. Online. Internet. 1-17-96 Available WWW:
http://www.soton.ac.uk/~engenvir/enviroment/air/acid.home.html
Durham, Jack. Acid Rain: A Student’s First Sourcebook. Diane Publishing Co.:
1994.
Morgan, Sally. Acid Rain. Franklin Watts, Incorporated 1999.
Phamornsuwana, Sam. “Effects of Acid Rain” 2-24-00. Online. Internet. 1-5-99
Available WWW: http://www.epa.gov/acidrain/effects.html
Pringle, Laurence. Rain of Troubles. Macmillan Publishing Co.: 1988.