بحث حول التلوث باللغة الانجليزية ( Pollution )

World Oil Pollution: Causes, Prevention and Clean-Up
Oil
in the oceans is one of the ugliest forms of marine pollution. Just
thinking about oil pollution in the oceans conjures up images of
massive tanker spills, oiled seabirds and shorelines covered with gooey
black oil. However, oil spills are not the major cause of oceanic oil
pollution. Instead the majority of marine oil pollution comes from
other sources. This page will examine the causes of marine oil
pollution and methods for pollution prevention and spill cleanup. Types
of Marine Oil Pollution
Oil spills are actually just a small
percent of the total world oil pollution problem. According to Ocean
Planet there are 706 million gallons of oil pollution in a given year.
That is a massive amount of oil! The following chart will indicate the
different methods of oil pollution and their respective percentage of
total pollution.
Types of Oil Pollution
Offshore Drilling
Large Oil Spills
Natural Seeps
Up in Smoke
Routine Maintenance
Down the Drain
Total World Oil Pollution Millions of Gallons
15
37
62
92
137
363
706 Percentage of the World Total
2.12 percent
5.24 percent
8.78 percent
13.03 percent
19.4 percent
51.42 percent
100
percent As you can plainly see from the chart oil spills only represent
a little over five percent of the total amount of oil pollution.
However, large oil spills are the most visible forms of oil pollution
in the world. The definitions of the different forms of oil pollution
are as follows. Offshore drilling pollution comes from operation
discharges and drilling accidents during oceanic oil exploration. Large
oil spills typically result from and oil tanker accidents such as
collisions and groundings. Natural oil pollution (seeps) comes from
seepage off the ocean floor and eroding sedimentary rocks. Natural oil
pollution into the marine environment has occurred for thousands if not
millions of years. Up in Smoke: This type of oil pollution comes from
oil consumption in automobiles and industry. Typically the oil
hydrocarbons find their way into the ocean through atmospheric fallout.
Oil pollution from routine maintenance occurs from ship bilge cleaning
and so forth. Lastly, oil pollution occurs from people dumping oils and
oil Oil tanker Amoco Cadiz. This tanker ran aground off the coast of
France in 1978 spilling 68.7 million gallons of oil. Spills such
asBlowout of exploratory well Ixtox 1 in 1979. When workers were able
to stop this blowout in 1980 an estimated 140 million gallons of oil
had spilled into the ocean. This is the second largest spill ever
smaller only than the deliberate oil spills that ended the Kuwait-Iraq
war of 1991. Image borrowed from Office of Response and Restoration,
National Ocean Service, National Oceanic and Atmospheric
Administration. Preventing Marine Oil Pollution
There are many
different methods of prevention to stop marine oil pollution. In the
case of oil exploration and oil tankers there are new procedures and
equipment to ensure that less pollution occurs. Most oil tankers now
are double hulled to reduce the chance of oil leakage if a tanker runs
aground. Oceangoing ships filter out most of the oil from bilge
maintenance to ensure that it does not reach the ocean. Used oil
recycling facilities exist to ensure people do not pour oil down
stormdrains and pollute millions of gallons of water. Another method is
for people to spray-paint fish pictures near storm-drains so people do
not put oils and other substances down the drain. This method is cheap
and remarkably effective as people find other ways to properly dispose
of oils. Even will all of these new methods for oil pollution reduction
oil pollution still does occur.
Dangers of Oil Pollution to the Marine Environment
So
why is oil so bad for the marine environment? Oil exposure damages
animal fur and feathers so they cannot stay warm and many of these
oiled animals will die by freezing to death. Other problems include
accidental poisoning by ingesting oil, blindness from oil exposure,
liver damage and other disabilities. If there is a large oil spill
humans have to clean up the excess pollution to ensure that fewer
animals will die. The following two pictures show beaches damaged by
oil pollution.
this one are very rare events. Image borrowed from
Office of Response and Restoration, National Ocean Service, National
Oceanic and Atmospheric Administration
products down stormdrOil
tanker Mega-Borg released 5.1 million gallons of oil as a result of an
oil transfer accident. Image borrowed from Office of Response and
Restoration, National Ocean Service, National Oceanic and Atmospheric
Administration.
ains after oil changes, urban street runoff and so
forth. The worst oil pollution comes from oil dumped into the drains
and road runoff. The following images illustrate some oil spills and
accidents thFreighter after running aground. Notice the oil leaking out
into the ocean. Image borrowIn both of these pictures notice the
amounts of oil pollution on the beaches. Any animals that come into
contact with this oil will likely be poisoned, get oil on their fur or
feathers and die from freezing or perhaps suffer permanent
disabilities. Beach clean-up occurs to minimize the chance of animals
either Water Pollution
Everybody needs fresh water. Without water
people, animals and plants cannot live. Although a few plants and
animals can make do with saltwater, all humans need a constant supply
of fresh water if they are to stay fit and healthy. Of the total supply
of water on the Earth, only about 3 percent of it is fresh, and most of
that is stored as ice and snow at the poles, or is so deep under the
surface of the Earth that we cannot get to it. Despite so much of the
water being out of reach, we still have a million cubic miles of it
that we can use. That's about 4,300,000 cubic kilometers of fresh water
to share out between most of the plants, animals and people on the
planet.
Whether water is clean enough to use, or too polluted
depends on many things such as where it is, whether there is enough for
everyone to use, what we do with it, and how we deal with the water we
have used before we let it run back to join the rivers and lakes.
The Developing World
In
the developing world the biggest problem is the shortage of water and
the lack of clean supplies. When water is very scarce people have to
make good use of it. That might mean using the same source of water for
drinking and cooking, a place to wash, a place to clean clothing, pots
and pans and a place to let the farm animals drink as well. The same
water is used by many people for many different purposes, and each time
the water becomes a little more polluted.
Imagine a river that is the only source of water for a series of farming villages along its banks.
The
people in the first village might be very careful and always get their
drinking water from above the village, do all their washing a little
further down stream, and let their animals drink in the river as it
leaves their village. By being very careful and aware of basic hygiene
they can try to stay healthy. They can do very little to protect
themselves from dead animals decaying in the river further upstream, or
from germs and parasites introduced to the water by wild animals.
As
the river leaves their village the water will have been polluted by
washed bodies, food scraps from washed pots and pans, and body waste
from the farm animals and village dwellers. The people in the next
village will have to drink this polluted water, and will suffer from
the diseases that accompany dirty water.
If an animal dies and
falls into the only water supply for miles around, the people still
have to drink the water. If the water is thick with mud and snails, but
is the only water within reach, people have to drink it.
Whether
the water source is a river, a lake or a well, the problems are similar
throughout the developing world; little piped and sterilised water, and
not enough water to go round means that the same source has to be used
for everything, and the risk of pollution and disease is very high.
The Developed World
You
might think that in developed countries with more money to spend on
health care, water supplies and pollution control, water pollution
wouldn't be a problem. If people in developed countries lived a life
similar to that of people in the developing countries, but used all
their high technology skills, the developed world might have an almost
pollution free water supply. Unfortunately that's not the case. The
developed world produces things in factories, people drive around in
cars, and want farmers to grow disease and pest free crops. The problem
is that people in the developed world create far more pollution than
their counterparts in the developing world.
Factories can produce
huge quantities of pollution that end up in the water supply and it's
not just the waste that goes directly into the rivers that causes
problems.
Smoke from chimneys can contain harmful chemicals such
as those which create acid rain. When it rains, all these chemicals are
brought back down to the ground in the rain drops, and then find their
way into the water supply.




المزاج:
الـبـلــــد: الجزائر
عدد الرسائل: 1754
تاريخ الميلاد: 07/04/1987
العمر: 22
موقعك على الانترنت: [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]
العمل/الترفيه: المدير المميز في المنتدى
المزاج: في منتهى الروعة و الإطمئنان فرح بما حوله
نقاط: 7450
تاريخ التسجيل: 08/03/2009


موضوع: رد: بحث حول التلوث باللغة الانجليزية الخميس مايو 28, 2009 2:53 pm
Chemicals
sprayed onto fields and crops, such as pesticides ( to kill insects ),
herbicides ( to kill weeds ) and fertilizers ( to make crops grow
faster, stronger and quicker ) can all soak into the soil when it
rains. Eventually the chemicals are washed into drainage ditches,
streams or rivers, and thus into the drinking water.
Sometimes
dangerous chemicals have been dumped in places where they can escape
into the water supply. Rubbish Dumps and Toxic Waste Sites are all
supposed to have a waterproof layer around them to stop chemicals
escaping, but sometimes it doesn't work. There are many older dumps
where the site isn't waterproof and nobody knows exactly what was
dumped there!
Love Canal and the U.S.A
A good example is the
Love Canal site near Niagra Falls in the United States of America.
During the 1940's and 1950's the canal was used as a dump for 22,000
tonnes of chemical wastes. The site was then filled in and covered in
soil, and houses built over the top. In 1978 it was noticed that many
people there were ill and that children were being born with defects.
It didn't take long to discover why, and the worst affected areas were
evacuated. Six years later the U.S government had discovered another
17,500 similar sites, 546 of which were considered to be dangerous to
the health of people living there. At many of these sites, chemicals
are leaking out into the groundwater supply causing serious pollution.
Did
you know that over 700 different chemicals have been found in US
drinking water when it comes out of the tap! The United States
Environmental Protection Agency (EPA) classifies 129 of these chemicals
as being 'particularly dangerous'.
In 1982 the EPA found poisonous
chemicals in the water supply of 35 different states. In 25 states the
contamination was so serious that wells had to be closed.
The River Rhine and Europe
The
River Rhine is regarded as being Europe's dirtiest river. Almost one
fifth of all the chemical production in the world takes place along its
banks. Despite the best attempt to purify the river water before it
becomes drinking water, Cornelius van der Veen, the head of the Dutch
water works in the Rhine catchment area, once said "Even
well-thought-out purification and reprocessing systems mean that just
about every substance present in untreated water is also to be found in
drinking water."
On 1st November 1986, the Sandoz chemical factory
in Switzerland had a warehouse fire. While the firemen were
extinguishing the flames they sprayed water over drums of chemicals
that were exploding due to the heat. The water and chemical mixture was
washed into the Rhine, dumping 30 tonnes of pesticides, chemical dyes
and fungicides into the river. As a result the river life died up to
100 miles downstream. Things could have been worse though. A nearby
building contained sodium, a metal that reacts violently with water. If
the fire hoses had been sprayed on the stored Sodium, the explosion
could have destroyed a group of storage tanks holding the nerve gas,
Phosgene!
After the fire had been put out, the German government (
West Germany at that time ) checked the water as it passed through
Germany. They discovered a high level of a chemical called Atrazine ( a
herbicide ) that wasn't listed as having been stored at the Sandoz
site. Eventually another giant chemical company, Ciba-Geigy, admitted
that they'd had an accident the day before and spilled 100 gallons of
Atrazine into the river. The West German government didn't believe this
figure and stated that nearer to 1500 gallons must have entered the
river.
As the monitoring of the Sandoz chemiWorld Trade Center/Pentagon Attacks
Why Did They Happen? What Do They Mean?
From Mark Sommer

The
collapse of the World Trade Towers and devastation of the Pentagon
drive home the stunning realization that for all our military might, we
Americans are no longer invulnerable to the world's deadly quarrels.
Out of the dust, rubble and grief emerge many questions:

… How
could a nation with the most fearsome firepower the world has ever
known fail to fend off a band of attackers with neither a nation,
weapon nor treasury of its own? Could any conventional military force,
any missile defense, any space laser, stop a malcontent from turning an
American commercial airliner into a weapon of mass destruction?
بحث حول التلوث باللغة الانجليزية