Legislation Flashcards
Ionising Regulations
Ionising Radiations Regulations (revised) 1999
What does Ionising Radiations Regulations(revised) 1999 cover?
All use of radiation and radioactive materials including radiography
A second booklet was published
which explains the regulations in a
shorter format this was named
“Approved Code of Practice for the Protection of Persons against Ionising Radiation arising from any work activity”
Lengthy document
Name of the second booklet was published which explains the regulations in a shorter format.
“Approved Code of Practice for the Protection of Persons against Ionising Radiation arising from any work activity”
Principles of Radiation protection
- Clinical justification
- Minimum exposure time, distance and shielding
- No dose limit should be exceeded
RPS
Radiation Protection Supervisor
Radiation Protection Supervisor Role
Appointed by practice
Principle or senior partner possibly Head Nurse
Responsibility : Radiography is carried out safely and in accordance with the Regulations and that the Local Rules are obeyed
Person need not be present for every radiographic examination
RPA
Radiation Protection Advisor
Radiation Protection Advisor Role
Diploma in Veterinary Radiology (knowledge of radiation physics, and medical physicists with an interest in veterinary radiography)
JAN 2005 They must hold a Certificate of competence from an appropriate issuing body.
RPA : Advise on radiation protection, demarcation of the controlled area and will draw up the Local Rules and Written Systems of Work.
The Controlled Area
Specific room, thick walls, reinforced if necessary
Allow for standing at least 2m from primary beam
Controlled area will be defined by the RPA
Area demarcated, labels warning notices whole area if possible
When X-Ray machine is disconnected from the power supply the room ceases to be a controlled area and may be entered
Special recommendations are made for flooring in cases where there may be occupied area below the radiography room.
Red light meaning
to warn radiography is in progress and prevent accidental entry
In addition all x-ray machines should have lights visible from the control panel indicating a) when machine is switched on b)or instead a noise such as a beep or buzz
Frequency of xray servicing
Should be carried out at least once a year
PPE for xrays
Aprons, gloves etc made of rubber impregnated with lead
Protective Clothing only protects against scatter radiation not the primary beam
Lead Aprons
Worn by person present in the X-Ray room during the exposure
Cover the trunk esp gonads and reach to mid thigh
Minimum thickness of 0.25mm LE
Double sided aprons offer best protection
Routine examination of clothing recommended
LE
Lead Equivalent
Lead Gloves
Lead gloves open palm mitts and hand shields must be available for manual restraint
0.35mm LE
Never appear in the Primary Beam.
Dosemeters
Worn on trunk beneath the lead apron
Worn only by the person to whom it is issued to
Must not be washed or tumble dryed or left in x-ray room nor exposed to heat or sunlight
Dosemeter types
Film badges
Thermoluminescent dosemeters (TLDs)
Film Badges
Small pieces of film usually blue
Contain small metal filters which allow the assessment of the type of radiation to which the badge has been exposed
Thermoluminescent dosemeters (TLDs)
Contain radiosensitive lithium fluoride crystals and are usually orange
On exposure to radiation the electrons in the crystals are rearranged, thus storing energy
During the reading process the crystals are heated and give off light in proportion to the amount of energy which they have stored this gives a quantitative reading.
Who are dosemeters obtained by and how often should they be sent off?
Dosemeters are obtained from the National Radiological Protection Board or Local Hospital.
They should be sent off for reading every 1-3 months depending on the work load.
NRPB
National Radiological Protection Board
1-3 months depending on radiographic case load
Dosemeters can be used to monitor radiation in the x-ray room
Readings should be monitored
Dose Limits
are amounts of radiation which are thought not to constitute a greater risk to health than that encountered in everyday life.
Background radiation dose limit
0.1 -0.3mSv
Dose limit woman of Reproductive capacity abdo
13mSv in any consecutive three month period
Dose limit Pregnant woman abdo
10mSv during the declared time of pregnancy,
mSv
Radiation is measured using the unit sievert, which quantifies the amount of radiation absorbed by human tissues.
One sievert is 1,000 millisieverts (mSv).
Principles of Radiation protection
Clinical justification
Radiography should only be undertaken if there is definite clinical justification for the use of the procedure
Principles of Radiation protection
minimum exposure time, distance and shielding
Any exposure of personnel should be kept to a minimum.
The three words to remember -Time, Distance and Shielding
(reduce the need for repeat exposures, stand well back, and wear protective clothing or stand behind a lead screen)
Alpha Particles
These are charged particles, given off during the decay process of radioactive materials.
The penetrative power of alpha particle radiation is not very strong and may be stopped by thin materials such as paper.
Alpha particles are only hazardous if they are allowed to enter the body via inhalation, cuts on the skin etc. Alpha particles are not used in radiation medicine.
Beta particles
Similar to alpha particles in that they are of a particle nature.
They are electrons and positrons, which are emitted during radiation.
Thin layers of water, glass or metal may stop them. They are dangerous if allowed to enter the body.
Gamma rays
Another type of radiation emitted during the decay process of radiation.
They have greater penetrative powers than alpha and beta particles but are absorbed by thickness of lead or concrete.
Gamma rays are similar to the electrically produced x-rays.
Alpha, beta, gamma rays collectively known
Alpha and Beta particles and Gamma rays are collectively known as ionising radiations because they produce an electrical effect called ionisation when they strike matter.
Ionisation frequently results in chemical changes, which may lead to change or injury of the organism.
What is the name of the law governing the use of radiation and radioactive materials?
The Ionising Radiation Regulations(revised) 1999
What was the name of the second booklet which was introduced to explain the Regulations?
Approved Code of Practice for the Protection of Persons against Ionising Radiation arising from any Work Activity.
Which booklet was published to explain the law as required by the veterinary profession?
Guidance Notes for the safe use of ionising radiations in veterinary practice.
Who introduced Guidance Notes for the safe use of ionising radiations in veterinary practice?
BVA in 2002
State the three main principles of radiation protection?
Time, Distance and Shielding
Describe the role of the RPS and who this may be?
The RPS is responsible for ensuring that radiography is carried out safely and in accordance with the Regulations, and that the Local Rules are obeyed, but the person need not be present at every radiographic procedure.
Principal, Senior Partner or Head Nurse
What are the qualification requirements for an RPA?
Veterinary Surgeons who hold a Diploma in Veterinary Radiology and who have a knowledge of radiation physics and medical physicist with an interest in veterinary radiography.
From Jan 2005 they will also have to hold a certificate of competence from an appropriate issuing body.
- Describe an ideal controlled area within a veterinary practice
Specific room, thick walls, reinforced if necessary
Allow for standing at least 2m from primary beam
Controlled area will be defined by the RPA
Area demarcated, labels warning notices whole area if possible
When X-Ray machine is disconnected from the power supply the room ceases to be a controlled area and may be entered
Special recommendations are made for flooring in cases where there may be occupied area below the radiography room.
What should be placed at the entrance to the X-Ray room?
Warning sign or red light should be placed at the entrance to the X-Ray room
How often should an X-Ray machine be serviced?
Yearly
State the LE of gloves and aprons
- Lead aprons 0.25mm to 0.5mmLE
* Lead gloves 0.35mmLE (0.5mmLE for equine patients)
What may be done to identify any cracks on protective clothing?
X-Raying of equipment to identify cracks
State two types of Dosimetry
Film Badges
TLD
How often should dosemeters be sent for reading?
1-3 Months depending upon work load
Define NRPB.
National Radiological Protection Board
Staff involved in radiography
Staff aged 16 or 17 have a lower MPD (maximum permissable dose) than adults aged 18 or over
<16 should not be present during radiography under any circumstances
Owners should not participate in radiography
Advisable not to involve pregnant women
Minimum no of people present
Only the person making the exposure should be present if the animal is artificially restrained
