Dangers of radiation Flashcards
what are the main types of radiation?
alpha
- chemo
-large molecule - need to ingest to enter the body
beta
- chemo
- large molecules
- byproduct of gamma
x-ray
- small particles, travel fast
- don’t require a medium
- easily cross barriers
gamma
- eg. iodine treatment
- can travel much greater
- no medium needed
- stays around for longer
how does radiation effect the body?
interrupts normal respiration of cells and disturbs chemical bonds
extremely high radiation can destroy nuclei
- why used for chemo
radiation poisoning = cumulative effects of the damage on the human from radiation exposure
- when cells are damaged they replicate wrong
what are the dangerous properties of radiation?
latent
- effects are delayed
invisible
- no appreciation for how much exposure on a daily basis
painless
- no appreciation for how much exposure on a daily basis
cumulative
- has a built up effect on the body
- eg. thyroid cancer
types of adverse effects of radiation?
somatic
- occur in exposed person
- acute - radiation poisoning/burns
- late - casinogenic effects
carcinogenic
- caused in tissues
- from modified DNA and gene mutation
- latent reaction from somatic
genetic
- mutations within ovaries and testes
- causes birth defects, pre-mature births, miscarriages and still births
source of radiation?
the tube head is the source of the primary beam
- lead lined
- never hold during exposure
primary beam - x-rays emitted through tube head
- high energy x-rays
- light beam diaphragm allows collimation
- collimation should be precise to limit and control radiation
no part of handler should come in contact with the primary beam
what is secondary radiation?
x-rays scattered off from the patient and outside the collimated field
- photons travel in straight lines, bounce off patient into new direction
what are the principles of radiation protection?
radiation should only be used with definite clinical justification
think about time, distance and shielding for minimum exposure
no dose limit should be exceeded
Radiation protection
What is required for a controlled area?
controlled area = area around the primary beam where the exposure to radiation exceeds the set limit by legislation
- typically 2m from the machine
once machine is disconnected no longer needs to be controlled
- requires electricity to produce rays
- so can be a multifunction room
all windows and door must be shielded
flooring and ceiling should be considered
- people above/below the room?
a warning sign must be displayed when machine is in use
- typically a red light or illuminated warning sign
machine must have a light which indicates it is on
there must be an audible indicator when an exposure is taking place
- know occurred and finished
Radiation protection
requirements for radiography equipment?
primary beam filtration device should be no less tan 2.5mm aluminum
must have a functioning collimation device
exposure button must allow operator to stand 2m away from the primary beam
have an electronic timer which allow the operator to abort if needed
- prep then expose
- can stop when prepping
x-ray table must be lead lines
machine serviced at least once a year
what needs to be recorded for every exposure taken?
patient name/ID, species, weight
date
position and view
settings used
staff involved
quality of the image
grid used
Radiation safety
PPE? how to care for it?
typically rubber or plastic containing lead
- lead equivalent - higher = safer
only effective against secondary radiation
care:
- must be visually checked regularly
- x-rayed for any cracks in the lead
- never fold any equipment
Radiation safety
types of radiation PPE? requirements? who should wear?
lead apron
- anyone in the x-ray room during an exposure
- at least 0.25mm LE
- ideally cover front and back
lead gloves
- used when manual restraint is unavoidable
- minimum 0.35 LE
lead sleeves
- tubes of lead rubber in which the arms can be places
- used when manual restraint is unavoidable
- minimum 0.35 LE
thyroid shields
- anyone in the x-ray room during an exposure
- neck guard to protect thyroid area
- minimum 0.35 LE
How should monitoring radiation exposure occur?
dosimeters
- personalised
- worn by anyone involved in radiography
- worn ono the torso
- worn under any PPE
- never leave in the x-ray room or in direct sunlight
they should be sent off to be read every 3 months (minimum) depending on case load
they can be mounted on a wall nearby
anyone that receives a measurement should be informed and practices adjusted
