Unfortunately, we can
never notice the penetration of this poison.
However, it can show its effects in a shocking way.
The radiation remains effective for years and years and you will never be aware of
the change. We are again facing a nuclear accident which has caught us without any preperations and its side effects which are going to last for years. It is obvious that the rings in the chain of neglect are being completed. Such a neglect can be accepted as normal for developing countries like Turkey,
however for Japan it was an unexpected case
of neglect... In a small town in northern Japan, in a nuclear fuel producing
plant, when uranium, the raw material of the atomic bomb
had a chemical reaction, this country has lived and will continue to live the biggest
nuclear disaster of her history... In the Nuclear fuel
producing plant, solid uranium was obtained from the liquid uranium to be used in nuclear power plants. When 12.4 kilo grams of uranium was poured into the tank instead of 2.4
kilo grams, nuclear fusion had started ending up with an explosion. As a consequence of this explosion, large amounts
of radiation spread into the air. As it is known, when the
neutrons found in the uranium atom hit the nucleus of the atom a break down in uranium
occurs. Radiation is the release of energy
from the atoms. When the uranium breaks down
large amounts of energy is released. This chain reaction forms the same system as the
atomic bomb. After all these events
have taken place, nuclear reaction had started without a chance of going backwards. After this point all the efforts are
concentrated for minimizing the side effects. In
the first stage, there wasn’t a chance of interfering let alone having the opportunity
of stopping the reaction. In that district
intensive radiation and a temporary rise in temperature was observed. The amount of radiation
in the center was fifteen thousand times more than the normal level. It spreads in circular forms as it moves further
away from the center. It has been stated that
5-6 hours after the event the reaction has stopped. However,
it seems very strange how the people without radiation-proof clothing could reach this result.
Moreover, the scientific data is not parallel with this finding. The properties of radiation can be stated as follows:-
The unit of measurement for radiation is RAD. RAD is the Radiation
Absorption Dose. It is the amount of
energy absorbed by one gram of matter. Radiobiology is the
branch of science which examines the effects of radiation on the living organisms. The cell is the smallest unit of the living organism, the majority of which consists of water. The building stones of a
cell are the enzymes, the proteins, the macro molecules such as DNA-RNA and mitochondria,
also organelles such as ribosomes. They are
all in an environment made up of water. Heat, excitation and
ionization are the natural outcomes of chemical reaction between radiation and matter. These lead to the formation of the chemical and
biological effects. The electrons in the
outer orbits of the elements play an important role in chemicall reactions. When these
electrons are pulled out by the effect of the radiataion then the chemical composition and
the properties of the matter change. The changes can be
observed in the macro molecules (DNA&RNA) of the cell or in the water molecules. With respect to thiis fact, the effects of
radiation on the cell are divided into two groups as direct and indirect: Direct Effects:- These can be observed in the macro molecules. For example, the enzymes belong to the group of
the macro molecules and there are numerous similar substances within the cell. So, when the structure of the molecule changes
because of the radioactive beam, then its function is taken over by the similar ones. Therefore, we cannot notice any change in the cell
because of the radiaton. The molecules such as DNA
are found only in the nucleus of the cell with the necessary amount. They do not have any similars and they are
called ‘’key molecules’’. The changes
that take place in the key molecules because of the radiation effect directly the
structure of the cell. The DNA molecule is found
in the chromosomes and it is the main determining factor for the transfer of genetic
properties to the coming generations. The
changes in the DNA cause either genetical mutation or the death of the cell depending on
the degree of change. Indirect Effects: Thy can be seen in the water molecules. The water molecules become ionized and the free radicals are released. Hydrogen peroxide, which is a by-product of this reaction is a very strong oxidant, such that it can disturb the metabolism of the cell. Moreover, the free
radicals may combine with the macro molecules and change their chemical structures. In this manner the
changes that are caused by the direct effects become apparent indirectly. Sensitivity to radiation
varies among different types of cells. In the
organism, the cells which are most sensitive to radiation are the lymphocytes, the basic
cells of the immune system. The least
sensitive or in other words the most resistent are the
cells of the muscles and the nerve cells. The cells which reproduce
at high speed and which are at the stage of division are more sensitive to radiation. The effects of the radiation on the organism vary depending on the type and quantity of irradiation. With respect to these
factors, the effects can either be seen immediately or become apparent after a silent
period. The silent period starts
from fifiteen days in high doses, whereas in cases of chronic irradiation with lesser
doses it can extend upto twenty years. We can classify the
effects of the radiation as follows:- 1) The effects of acute radiation in high doses 2) The effects chronic radiation in less doses It occurs once with a high dose of radiation. This is seen in
the atomic bomb, in the accidents that take place in the nuclear
power plants, and in the experiments
conducted with the animals. The effects are directly
related to the dose. First of all, the
dividing speed of the cell decreases,
a break down in the chromosomes takes place, there is
a decrease in the red blood cells and
an inactivity in the immune system. 300-600 RAD = Due to the inactivity of the
bone marrow, the probability of death
is 50%. 1000-1200 RAD= 100% of death due to the extensive blood disorders in the digestive system. 5000RAD= The brain is effected immediately resulting with a sudden death. 2.The effects of
chronic radiation in low doses: In the technicians
dealing with the X-Ray devices and radiologists dryness in the hands, pigmentation, early
cases of cataract, infertility and leuchomia
can be observed. Ahmet F. Yüksel
Bibliography:
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Let us immediately
remember the case of
