1. Biological Effects of Ionising Radiation

2. Radio Sensitivity
Radio Sensitive Tissues
Radio Resistant Tissues

3. Radio Sensitive Tissues
Reproductive cells of the ovary and the Testis
Blood forming Tissues in bone marrow, spleen, lymph nodes
Epithelium of the Skin
Epithelium of the Intestinal Tract

4. Radio Resistant Tissues
Bone
Liver
Kidney
Muscle
Nerves

5. Effects of Radiation
Primary Effects occur when the initial interaction is with atoms in cells like those in DNA molecules.
Secondary Effects occur with the formation of free radicals which are very reactive and can chemically attack molecules such as DNA.

6. Radiation Effects
Stochastic Effects
Non-Stochastic Effects

7. Stochastic Effects
The probability of the effect increases with the dose.
No established threshold.
Examples: Cancer, Genetic Mutations

8. Non-Stochastic Effects (Deterministic)
The severity of the effect increases with the dose.
Generally a threshold exists. Below the threshold, no effects occur.
Effects often result from the collective injury of many cells.
Examples: Cataracts, Skin Burns, Lowering of Blood Cell Counts

9. Effects of Acute Radiation Exposure
On the Blood
On Digestion
On the Central Nervous System

10. On the Blood Dose level between 200 and 1000 rad
Damages red blood cell forming organs - loss of breath, tiredness
Affects white blood cell production - reduced ability to fight infection
Lowered platelet count - hemorrhaging and slower healing process
Death by infection and hemorrhaging

11. On Digestion Dose level between 1000 and 5000 rad
Stops new epithelial cells and absorption
Nausea and vomiting
Dehydration from diarrhea and low water absorption
Electrolyte imbalance
Death by Circulatory collapse from loss of fluids

12. Central Nervous System
Dose Level greater than 5000 rad
Convulsions
Tremors
Lethargy
Death by respiratory/brain failure