Radiation Flashcards
Give examples of radiation in the form of waves
Wavelength-
Non-ionizing: radio, microwave, infrared, visible light, ultraviolet light
Ionizing: x-ray, gamma ray
Define radiation and radioactivity
Radiation-is energy in the form of electromagnetic waves or particles
Radioactivity-is The emission of ionizing radiation or particles caused by the spontaneous transformation of atomic nuclei
Give examples of radiation particles:
Alpha particles & beta particles (both ionizing)
Describe and explain the differences between ionizing and nonionizing radiation. Be able to give examples of each.
Ionizing radiation-the radiation has enough energy to eject an electron from its atomic shell. (They are unstable and want a more stable configuration)
Non-ionizing radiation-really refers to any type of electromagnetic radiation ( does not carry enough energy to completely eject an electron from an atom or molecule)
Examples:
Ionizing-some ultraviolet, x-ray, GammaRay’s
nonionizing-radio waves, microwaves, infrared, visible light
Natural sources of radiation and artificial sources of radiation examples?
Natural sources of radiation; sunlight (UV)
Radioactive material (radon)
Cosmic rays
Artificial sources of radiation;
Radiofrequencies
microwaves
tanning beds
X-ray tubes
Accelorators of particles
Describe alpha particles, beta particles and gamma rays (and what type of material attenuates/stops each)
Alpha particles-large slow particles (charged particle) can it be stopped by paper
Beta particles smaller faster particles (charged particle) but can be stopped by aluminum
Gamma rays -(photons) fast , tiny high-energy-can penetrate through almost anything including lead (this is the dangerous form because they cause DNA chromosomal damage and can’t really be attenuated or stopped )
What are the biophysical effects of radiation at the atomic molecular and DNA levels?
At the atomic level:
Interactionsof radiation with matter create ionizations
Creation of numerous secondary electrons
Molecular:
Radiolysis of water equals disassociation of molecules by nuclear radiation
(All this means is on the atomic level free radicals are produced- free radicals are detrimental to the human body)
Biophysical Effects:
Chromosomal damage 3 different kinds :
1) base damages to the DNA
2) single-strand breaks in the DNA
3) double strand breaks in the DNA
What is the trend in medical radiation exposure from 1980 to 2006?
In 1980 medical Radiation was 15% of radiation exposure. (for total of 3.6 mSv per capita)
In 2006 medical radiation makes up 47% of radiation exposure. (A total of 6.2 mSv per capita)
What is the difference between deterministic and stochastic effects?
Deterministic effects-death of cells caused by radiation.
Threshold dose (there is a minimum dose - once it's passed damage is certain ) as the dose increases so does the severity of injury= direct correlation
High doses of radiation
Early effects: days-weeks
Late effects months - years
Stochastic Effects- due to mutations of DNA , cause cancer
No threshold
Risk increases with radiation dose
Cancer
Late Effects -years
Examples of deterministic and stochastic effects?
(Large dose short period of time)
Deterministic examples include:
Desquamation after overexposure during fluoroscopy procedure
Hair loss after exposure during a CT exam
Acute radiation sickness syndrome by poisoning
(Stochastic effects-radiation exposure over long periods of time)
Stochastic examples include:
Japanese A-bomb survivors
Chernobyl cleanup workers and children exposed to fall out
Radiologist
What are the three principles of radiation protection?
Justification-should do more good than harm
Optimization - (ALARA)-as low as reasonably achievable -taking into account economic and societal factors
Limitation-should not exceed the appropriate limits recommended by the commission
Which organs are most at risk from optical nonionizing radiation?
Eyes and skin are the organs most at risk
What are the effects of UV radiation?
Negative effects:
Skin-acute and chronic effects
Acute-arrhythmia (sunburn)
Chronic- Freckles
Loss of skins elasticity (wrinkles and dry, course skin)
Skin Cancer- basal cell carcinoma, squamous cell carcinoma, melanoma
Eyes-cataracts
Health benefits from UV radiation:
Synthesis of vitamin D
