| | | | | ii.
The mechanism by which the radiation can affect:
|
Mechanism of radiation affect |
Radiation can affect in
two types; Direct &
indirect.
A) Direct:
B) Indirect:
Interacting with the water that makes up most of
the cell’s volume. Then break the bonds that hold the water molecule
together, producing fragments such as
hydrogen (H) and hydroxyls (OH). However, they could combine to form toxic substances, such
as hydrogen peroxide (H2O2), which can contribute to the destruction of
the cell.
|
Indirect |
|
Indirect |
| ii.
The biological effects of the radiations "Long term &
Short term":
Biological effects of
radiation are typically divided into two categories. The first category consists of exposure to
high doses of radiation over short periods of time producing acute or short term effects. The second category represents exposure to
low doses of radiation over an extended period of time producing chronic or long term effects.
A) Short
term or acute effects:
It depends upon the
amount of radiation that our bode receive.
< 5 rad: No immediate observable effects.
~ 5 rad to 50 rad: Slight blood changes may be detected
by medical evaluations.
~ 50 rad to 150 rad: Slight blood changes will be noted
and symptoms of nausea, fatigue, vomiting.
|
Fatigue |
~ 150 rad to 1,100 rad: Severe blood changes will be noted
and symptoms appear immediately. Approximately 2 weeks later, some of those
exposed may die. Death is due to the destruction of the blood forming organs.
Without white blood cells, infection is likely. At the lower end of the dose
range, isolation, antibiotics, and transfusions may provide the bone marrow
time to generate new blood cells and full recovery is possible. At the upper
end of the dose range, a bone marrow transplant may be required to produce new blood
cells.
|
Blood change |
~ 1,100 rad to 2,000 rad: The probability of death increases to
100% within one to two weeks. The initial symptoms appear immediately. A few
days later, things get very bad, very quickly since the gastrointestinal system
is destroyed. Once the GI system ceases to function, nothing can be done, and
medical care is for comfort only.
> 2,000
rad: Death is a
certainty. At doses above 5,000 rad, the central nervous system can’t control
the body functions, including breathing blood circulation. Everything happens
very quickly. Nothing can be done, and medical care is for comfort only.
B) Long
term or chronic effects:
|
The main two types of long term effects |
There are three general categories of effects
resulting from exposure to low doses of radiation. These are: Genetic(Include
In utero), Somatic and In utero.
1-
Genetic: The Genetic Effect involves the
mutation of very specific cells, namely the sperm or egg cells. Mutations of these reproductive
cells are passed to the offspring of the individual exposed. One very important
fact to remember is that radiation increases the spontaneous mutation rate, but
does not produce any new mutations.
2-
Somatic effect: Effect is suffered by the individual exposed Primary consequence is cancer.
|
Radiation also cause thyroiditis |
3-
In utero: It is branch of genetic effect. Effects of radiation on
embryo/fetus Intrauterine
Death, Growth Retardation, Developmental Abnormalities and Childhood Cancers.
| | | |
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