Radiations impact on living tissue (2) Flashcards
Variables that contribute to the effects of radiation exposure
- type of radiation
- strength of radiation energy
- Part of body exposed
- Duration of exposure
- Individual biological factors
Biological effects of radiation exposure
- Radiation burns
- Radiation sickness
- Cataracts
- Genetic effects
- Cancer
Define ALARA
As Low As Reasonably Achievable
Particulate Radiation exposure can have the potential to be _____ than an equivalent exposure of waveform radiation.
far worse
How is someone exposed to particulate radiation?
Result of leaking radioactive materials (rare)
- Skin contact
- Inhaled
What is the ICRP?
International Commission on Radiological Protection
What are the two main objectives of the ICRP guidelines?
- prevent severe or over exposure
2. limit prolonged or “chronic” exposure to acceptable levels
Name the effective dose limits for Radiation workers
per 1 year
per 1 year (special circumstance)
per 5 years
per balance of pregnancy
20mSv/year (2rem)
50mSv/year (5rem)
100mSv/5 years (10rem)
2mSv/balance of pregnancy (200mrem)
Name the effective dose limits for the general public
per 1 year
1mSv/year (0.1rem)
What is an Effective Dose?
Sum of all tissues weighted equivalent doses.
What are the Equivalent Doses for different parts of the body?
Skin, Hands/Feet, Lens of eye for NEW and Public
Skin:
- 500mSv for NEW
- 50mSv for Public
Hands/Feet:
- 500mSv for NEW
- 50mSv for Public
Lens of eye:
- 150mSv for NEW
- 15mSv for Public
Classification of Radiation Effects
- First person or Genetic
- Time of exposure
- Time for effects
- Prediction of effects
Somatic Effects
Effects experienced by the individual who received the exposure
Genetic Effects
Effects passed from parent to child due to mutations in reproductive cells from exposure
Acute Exposure
Exposure to a large dose in a short time period
Chronic Exposure
Exposure to a small dose over a long time period
Somatic Effects
Effects evident a short time after exposure
Delayed Effects
Effects evident after years, decades or generations after exposure
Stochastic Effects
Effects associated with long-term, chronic exposure with no known minimum threshold.
Non-Stochastic Effects
Effects from high levels of radiation, that become more severe as exposure increases.
Below a known threshold, effects do not occur.
Name the two clinical effects of Ionization
Direct Action
and
Indirect Action
What is Direct Action?
Cell damage occurs when radiation interacts DIRECTLY with a cells molecules.
- damage DNA, tissues or organs (increase or decrease in hormone and enzyme production)
- Alteration of cell birth rate
- Death to affected tissues or organs
What is Indirect Action?
Radiation interacts with water molecules in the body, producing Free Radicals.
- Prevents cell division (large cells)
- Produce genetically altered cells
- cell death
- alter cell birth rate
What are Free Radicals?
Particles formed when radiation interacts with water in the body. Formed when bonds between atoms are broken.
- Unstable (+ charge)
- Highly reactive
Factors that can impact Biological effects
- exposed tissue’s radio sensitivity
- type of radiation
- percent of body exposed
- amount of dose received
- dose rate
- age of person
- biological differences
New cells are ___ affected by radiation
more
the more active the cell the ____ affected by radiation
more
Undernourished cells are ____ affected by radiation
less
Most affected cells are:
those related to blood and blood-forming organs
- red (erythrocytes)
- white (leucocytes)
- platelets (thrombocytes)
Sensitivity and Function of:
White Cells (spleen and lymph nodes)
High
Scar tissue and promote antibodies
Sensitivity and Function of:
White Cells (bone marrow)
High
Combat bacterial infections
Sensitivity and Function of:
Basal Cells
High
Produce complex cells (gonads, bone marrow, cornea, skin, alimentary canal)
Sensitivity and Function of:
Alveolar Cells
High
Absorb oxygen from air and release CO2 into the blood
Sensitivity and Function of:
Bile Duct Cells
Moderate
Associated with digestion
Sensitivity and Function of:
Cells of Tubules of kidneys
Moderate
Keep toxins from entering bloodstream, produce body functioning hormones (regulate blood pressure, produce red blood cells, regulate minerals and fluid)
Sensitivity and Function of:
Endothelial Cells
Moderate
Line the heart and blood vessels
Sensitivity and Function of:
Fat and Bone
Low or Radio-Resistant
Connective tissue (muscles, ligaments, tendons)
Sensitivity and Function of:
Nerves and Brain
Low or Radio-Resistant
Brain function and fine motor skills
A whole body does is ____ than a restricted dose
ALWAYS worse
The higher the does received in one exposure the ____ the damage
larger/more
A dose received in a short time frame is ____ than the same dose over a longer time frame
worse
will cause more damage, tissues can receive much larger doses over time
Who is the most affected by radiation and why?
Fetuses, more cell division is occurring.
When do signs of radiation sickness first appear?
entire body, absorbed dose of at least 1 Gy
Doses after this point are no longer treatable and often lead to death
6 Gy, death within 2 days or several weeks
What are some early symptoms of radiation sickness?
Nausea
Vomiting
after this stage more dangerous complications occur
Effects from high radiation doses include:
- ulcers
- blood change
- dizziness
- disorientation
- hair loss
- infections
Effects from VERY high doses include:
- destruction of intestinal lining
- internal bleeding
- rapid weight loss
- nervous system damage
- death within hours or days
Steps to repair and recover from radiation exposure
- complete rest
- sterile environment
- antibiotics
- blood transfusions
- intravenous feeding
Define recovery period
Time required for radiation damage to be repaired by the body
