rain is a great problem in our world. It causes fish and plants to die in our
waters. As well it causes harm to our own race as well, because we eat these
fish, drink this water and eat these plants. It is a problem that we must all
face together and try to get rid of. However acid rain on it's own is not the
biggest problem. It cause many other problems such as aluminum poisoning. Acid
Rain is deadly. WHAT IS ACID RAIN? Acid rain is all the rain, snow, mist etc
that falls from the sky onto our planet that contains an unnatural acidic. It is
not to be confused with uncontaminated rain that falls, for that rain is
naturally slightly acidic. It is caused by today's industry. When products are
manufactured many chemicals are used to create it. However, because of the
difficulty and cost of properly disposing of these products they are often
emitted into the atmosphere with little or no treatment. The term was first
considered to be important about 20 years ago when scientists in Sweden and
Norway first believed that acidic rain may be causing great ecological damage to
the planet. The problem was that by the time that the scientist found the
problem it was already very large. Detecting an acid lake is often quite
difficult. A lake does not become acid over night. It happens over a period of
many years, some times decades. The changes are usually too gradual for them to
be noticed early. At the beginning of the 20th century most rivers/lakes like
the river Tovdal in Norway had not yet begun to die. However by 1926 local
inspectors were noticing that many of the lakes were beginning to show signs of
death. Fish were found dead along the banks of many rivers. As the winters ice
began to melt off more and more hundreds upon hundreds more dead fish (trout in
particular) were being found. It was at this time that scientist began to search
for the reason. As the scientists continued to work they found many piles of
dead fish, up to 5000 in one pile, further up the river. Divers were sent in to
examine the bottom of the rivers. What they found were many more dead fish. Many
live and dead specimens were taken back to labs across Norway. When the live
specimens were examined they were found to have very little sodium in their
blood. This is typical a typical symptom of acid poisoning. The acid had entered
the gills of the fish and poisoned them so that they were unable to extract salt
from the water to maintain their bodies sodium levels. Many scientist said that
this acid poising was due to the fact that it was just after the winter and that
all the snow and ice was running down into the streams and lakes. They believed
that the snow had been exposed to many natural phenomena that gave the snow it's
high acid content. Other scientists were not sure that this theory was correct
because at the time that the snow was added to the lakes and streams the Ph
levels would change from around 5.2 to 4.6. They believed that such a high jump
could not be attributed to natural causes. They believed that it was due to air
pollution. They were right. Since the beginning of the Industrial revolution in
England pollution had been affecting all the trees,soil and rivers in Europe and
North America. However until recently the loses of fish was contained to the
southern parts of Europe. Because of the constant onslaught of acid rain lakes
and rivers began to lose their ability to counter act their affects. Much of the
alkaline elements; such as calcium and limestone; in the soil had been washed
away. It is these lakes that we must be worried about for they will soon become
extinct. A fact that may please fishermen is that in lakes/rivers they tend to
catch older and larger fish. This may please them in the short run however they
will soon have to change lakes for the fish supply will die quickly in these
lakes. The problem is that acid causes difficulties the fish's reproductive
system. Often fish born in acid lakes do not survive for they are born with
birth defects such as twisted and deformed spinal columns. This is a sign that
they are unable to extract enough calcium from the water to fully develop their
bone. These young soon die. With no competition the older,stronger can grow
easily. However there food is contaminated as well by the acid in the water.
Soon they have not enough food for themselves and turn to cannibalism. With only
an older population left there is no one left to regenerate themselves. Soon the
lake dies. By the late 1970s many Norwegian scientists began to suspect that it
was not only the acid in the water that was causing the deaths. They had proved
that most fish could survive in a stream that had up to a 1 unit difference in
PH. After many experiments and research they found that their missing link was
aluminum. Aluminum is one of the most common metals on earth. It is stored in a
combined form with other elements in the earth. When it is combined it cannot
dissolve into the water and harm the fish and plants. However the acid from acid
rain can easily dissolve the bond between these elements. The Aluminum is then
dissolved into a more soluble state by the acid. Other metals such as Copper
(Cu), iron (Fe) etc can cause such effects upon the fish as well however it is
the aluminum that is the most common. For example: CuO + H2SO4 ----------* CuSO4
+ H2O In this form it is easily absorbed into the water. When it comes in
contact with fish it causes irritation to the gills. In response the fish
creates a film of mucus in the gills to stop this irritation until the irritant
is gone. However the aluminum does not go always and the fish continues to build
up more and more mucus to counteract it. Eventually there is so much mucus that
it clogs the gills. When this happens the fish can no longer breath. It dies and
then sinks to the bottom of the lake. Scientists now see acid, aluminum and
shortages of calcium as the three determining factors in the extinction of fish.
As well there is the problem of chlorine. In many parts of the world it is
commonly found in the soil. If it enters the fish's environment it can be
deadly. It affects many of the fish's organisms and causes it to die. As well it
interferes in the photosynthesis process in plants. NaOH + HCl ----* NaCl + H2O
The carbon in the water can become very dangerous for fish and plants in the
water if the following reaction happens: CaCO3 + 2HCl ---* CaCl2 + H2CO3 then
H2CO3 ---* H2O + CO2 The salt created by this reaction can kill. It interferes
directly with the fish's nervous system. Acid lakes are deceivingly beautiful.
The are crystal clear and have a luscious carpet of green algae on the bottom.
The reason that these lakes are so clear is because many of the decomposers are
dead. They cannot break down that material such as leaves and dead animals.
These materials eventually sink to the bottom instead of going through the
natural process of decomposition. In acid lakes decomposition is very slow.
"The whole metabolism of the lake is slowed down." During this same
period of time the Canadian department of fisheries spent eight years dumping
sulfuric acid (H2SO4) into an Ontario lake to see the effects of the decrease in
the PH over a number of years. At the PH of 5.9 the first organisms began to
disappear. They were shrimps. They started out at a population of about seven
million, but at the pH of 5.9 they were totally wiped out. Within a year the
minnow died because it could no longer reproduce it's self. At this time the pH
was of 5.8. New trout were failing to be produced because many smaller organisms
that served as food to it had been wiped out earlier. With not enough food the
older fish did not have the energy to reproduce. Upon reaching the pH of 5.1 it
was noted that the trout became cannibals. It is believed this is due to the
fact that the minnow was nearly extinct. At a pH of 5.6 the external skeletons
of crayfish softened and they were soon infected with parasites, and there eggs
were destroyed by fungi. When the pH went down to 5.1 they were almost gone. By
the end of the experiment none of the major species had survived the trials of
the acid. The next experiment conducted by the scientists was to try and bring
the lake back to life. They cut in half the amount of acid that they dumped to
simulate a large scale cleanup. Soon again the cuckers and minnows began to
reproduce again. The lake eventually did come back; to a certain extent; back to
life. THE NEW THEORY: A scientist in Norway had a problem believing that it was
the acid rain on it's own that was affecting the lakes in such a deadly way.
This scientist was Dr Rosenqvist. "Why is it that during heavy rain, the
swollen rivers can be up to fifteen times more acid than the rain? It cannot be
the rain alone that is doing it, can it?" Many scientist shunned him for
this however they could not come up with a better answer. Soon the scientists
were forced to accept this theory. Sulfuric acid is composed of two parts, know
as ions. The hydrogen ion is what make a substance acid. The other ion is
sulphate. When there are more hydrogen ions then a substance is acid. It is this
sulphate ion that we are interested in. When the rain causes rivers to overboard
onto the banks the river water passes through the soil. Since the industrial
revolution in britain there has been an increasing amount of sulphur in the
soil. In the river there is not enough sulphur for the acid to react in great
quantities. However in the soil there is a great collection of sulphur to aid
the reaction. When it joins the water the pH becomes much lower. This is the
most deadly effect of acid rain on our water!!! The water itself does not
contain enough sulphur to kill off it's population of fish and plants. But with
the sulphur in the soil it does. CONCLUSION: Acid rain is a big problem. It
causes the death of our lakes, our rivers, our wild life and most importantly
us. As well it causes other problems that are very serious as well such as the
release of aluminium and lead into our water supplies. We are suffering because
of it. In Scotland there are many birth defects being attributed to it. We must
cut down the releases of chemicals that cause it. But it will take time, even if
we were to stop today we would have the problem for years to come because of the
build up in the soil. Let's hope we can do something.

Bibliography
Penguin Publishing House, 1987 , Pearce Fred Acid Rain. What is it and what
is it doing to us? New York Publishers, 1989, William Stone Acid Rain. Fiend or
Foe? Lucent books, Inc. 1990, Steward Gail Acid Rain.