The harmful effects of the excessive dose of the ionizing radiation can be divided into two types. These are as follows:
- Deterministic effects and
- Stochastic effects
We shall discuss them one by one in detail.
The deterministic effects are health effects of the absorbed radiation that starts once the dose reaches a threshold value. Once the threshold value is crossed and the effects become visible, the severity of the effects increases with the radiation dose. In other words, you will not see any effect below the threshold value. The threshold value may be as low as 0.1 Gray or as high as 0.25 Gray.
The symptoms of deterministic effects are nausea, vomiting and fatigue. The symptoms start only after a certain number of cell deaths occur in an organ.
The examples of deterministic effects of ionizing radiation are:
- Acute radiation syndrome by acute whole-body radiation.
- Radiation burns, from radiation to a particular body surface.
- Radiation induced thyroiditis.
- Chronic radiation syndrome, from long-term radiation.
- Radiation induced lung injuries
Stochastic effects occur by chance. They are not related to the radiation dose threshold. Although the probability of occurrence of the effects is proportional to the dose but the severity of the effect is not dependent upon the received dose.
The stochastic effects are categorized into two categories. They are somatic and hereditary effects.
Somatic & Hereditary Effects
The somatic effects are seen in the person who has received the radiation. The hereditary effects are those that are seen in the offsprings of the exposed person. The cancer in an individual caused by excessive amounts of radiation is somatic, whereas the abnormalities developed in a fetus due to excessive amounts of radiation in a mother is hereditary.
Therefore, for the safety of a patient and their offsprings, a treating dentist must follow the principle of ALARA (As Little As Reasonably Acceptable).
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