Реферат на тему Rachel Carsons Book Essay Research Paper Rachel
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Rachel Carsons Book Essay, Research Paper
Rachel Carson s Silent Spring begins with a short story depicting a made-up town in the
heart of America where all life once lived in harmony with its surroundings. Carson quickly
presents her central issue by quickly describing the disasters this made-up town faces. Because
what silenced the made-up town was the inhabitants and their ignorance to the environmental
hazards they had imposed as a result of their decisions. Although the town does not exist, the
potential of the occurrence of these disasters is an eye-opener for the reader, as well as a great
lead in for the book.
A reoccuring theme in biology, life is a result of the interaction between living things and
their non-living environment. However, this balance is disrrupted when the non-living
environment is contaminated by dangeroud materials. Carson states that since the 1940’s over
200 basic chemicals have been created for killing insects, weeds, rodents, and other organisms
considered pests by our society. The introduction of such chemicals into our environment
have caused an unmeasurable amount of damage. The environmental damage caused by a
pesticide must be measured in the totality of life forms it affects, ie., along the entire food chain.
Sprays to kill mosquitoes accululate in fish, in fish-eating birds, and in mammals eating birds
and fish (including man!).
Today s insecticides are no match to the inorganics and the Arsenicals used before World
War I. Of these, the most widely used can be classified as either DDT or the organic phosphorus
insecticides. DDT is a chlorinated hydrocarbon. Many believe this pesticide is harmless
because there have been a substantial number of people that have come in contact withteh
chemical and have suffered no physical damage. But the truth is that DDT is very harmful.
Although the harmful properities of the chemical is not seen immediately, its damageing
characteristics become measurable as the chemical is passed on from organism to organism
through the food chain; becoming more and more harmful with each transfer. Long term
exposure to pesticides may result in the gradual accumulation of a lethal dose. While the residue
at the time of application may be within an acceptable tolerance, fat-soluble compounds may
continue to accumulate in body fat and in substances like milk to very high levels. These
chlorinated hydrocarbons were directly responsible for tremendous environmental damage.
Several species of birds were driven to near extinction before the full impact of the insecticide
was realized. As for Phosphorus insecticides, there are obvious hazards. This chemical is
known for its acute poisoning of people such as people who spray it or people that may come in
contact with it through drifting spray comming from vegetation coated with it. By destroying
enzymes in the body that perform specific functions, the physical harm done to the person is very
quickly. To workers dealing with teh chemical, the danger has become serious. As a result of
teh dangers, certain states have established labs in which workers dealing with the chemical can
be tested and receive an accurate diagnosis from expert researchers.
Along with the potential to harm living organisms, the pollution of the non-living
environment, which is equally important in the interaction responsible for the emergence of life,
is also discussed by Carson. The consequnces of surface and ground water contamination can
act as carriers for the fatal pesticides. Although nature s purifying properties can potentially
mend an amount of the damage, at the rate at which these chemicals are introduced into the
environment constantly it is impossible. The sources of the pollution come from radioactive
waste reactors, factories, fall-out from nuclear explosions and even domestic waste from cities.
These cities receiving their drinking water from rivers had a higher death rate from cancer than
did those whose water came from sources such as wells. At water treatment plants, the potential
reactive potential of chemicals in water was such that plants were not able to remove some
chemicals from teh drinking water. They feared that the reation of the removed chemicals in
catch basins with each other would form into toxic compounds that would too increase cancer
hazards from pollutants.
Carson also goes on to discuss the design sof insect control programs in the 60 s.
Wide-area “eradication” programs aimed at control or localization of imported pests are almost
always unsuccessful, and extract severe penalties from non-target organisms. She explains that
in designing insect control programs, the possibility of successfully controlling an insect
population is more effective in natures potential than man s. Also, the species desired to be
controlled reproduce once the potential of the environment to control it has weakened. Carson s
underlying idea is that biological methods are the solutions to such a problem. Such amethod
could be the male sterilization, which consists of the release of large numbers of sterilized
insects. When released, the sterilized males would compete with the wild males to such an
extent that only infertile eggs would be reproduced and the population would die out.
Carsons discussion of the effects of pesticides on living organisms and the non-living
environment came, in Al Gore s words, as a cry in the wilderness. It was an awakening to
many that began the environmental movement. In her final statement, she declares that mans
desire to control nature is philosophy born in the Stone Age among the Neanderthals that has
been passed on till now. The irony is this desire for total control could become an alarming
reality, but unfortunately it would not be man s true intentions; for all the research and
formulated chemicals engineered to control a percentage of a species could be the extinction of
many others.