Lecture 25 - Radiation Safety Flashcards
1
Q
Ionising radiation
A
- radiation removes electrons from atoms to form ions
- can be carcinogenic, leukemogenci, mutagenic ot teratogenic
2
Q
Non ionising radiation
A
- radiation energy cannot create ions but can have other effects such as thermal or photochemical
- not carcinogenic
3
Q
Alpha particles
A
- nasty and dangerous
- not used except for some radioisotype therapy
4
Q
Beta particles
A
- same as electrons
Nasty - used for therapy
5
Q
Gamma rays
A
- electromagnetic radiation
- penetrating
- not as nasty as particles
- safe for imaging but at high intensities can also be used for therapy
6
Q
X rays
A
- physicall identical to gamma rays but come from electron, not nucleus
- penetrating -> used for imaging
- relatively safe for imaging
- used for radiotherapy at high intensity
7
Q
Appliation of ionising radiation
A
- radiology - x ray
- nucleuar medicine: radionuclides
- radiotherapy - X ray, particles and radionuclides
- dental
- radio-labelling techniques: radionuclide
- blood irradiation - gamma rays
8
Q
Non ionising radiation appliation
A
- MRI
- UV therapy
- lasers” high and low power
9
Q
Radiation dose units
A
- absorbed dose: gray Gy
- effective dose: Sievert SV
10
Q
Physical effect of radiation
A
- energy absorption, ionisation
11
Q
Physico-chemical effect of radiation
A
- interaction of ions with molecules, formation of free radicals
12
Q
Chemical effect of radiation
A
- interaction of free radicals with molecules, cells and DNA
13
Q
Biological effect of radiaiton
A
- cell death, change in genetic data in cell, mutations
14
Q
3 types of radiation effect
A
- Stochastic: probability of effect related to dose
- DEterministic: threshold for effect: no effect below, above, certaintiy and severity increases with dose
- hereditary (genetic)
15
Q
Eg of stochastic effect
A
- DNA effects, mainly repaired
- carcinogenesis, leukemogenesis
