Radiation Protection Flashcards
You are not expected to memorise safe doses etc., the procedures for creating a safe building
(slide 34 to 45), or details of the duties specific to radiologists / radiographers
-
Slide 6 - list the principles of a risk assessment
- Look for the hazards
- Decide who may be harmed and how
- Evaluate the risks and decide whether existing controls are adequate or if more should be done
- Record the findings
- Review the assessment and revise it if necessary
Slide 9 - identify the subjects who are most at risk from ionising radiation, and additional safety measures that they require
- Female employees need to be advised about informing employer about pregnancy
- Risk assessment carried out
- Ensure dose to foetus <1 mSv
- In x-ray departments most cases will not require change in work practices beyond increased dose monitoring
- prevent contamination of breastfeeding employees
Slide 12 to 15 - define “classified person” and explain the safety measures required by both classified and non-classified individuals
Classified person
= Any employee likely to receive a dose >3/10 of any dose limit has to be designated as a ‘classified person’
- dose monitoring
- periodic medical exams
IRR17 -Doses should be assessed for classified persons
Classified if likely to receive a dose greater than 3/10 of any dose limit (6 mSv whole body dose) or 15mSv eye dose
Slide 16 to 20 - explain the types of monitor that may be used in different circumstances
- Whole Body dose –> measured by whole body badge beneath apron assumes radiation is distributed uniformly across whole body
- Thyroid/Eye Dose –> Staff standing close to the patient during a fluoroscopy and likely to get significant eye/thyroid dose (>1/10 of dose limit) should wear collar or head badge
- Extremity doses –> Staff who are likely to get their fingers in or near the x-ray beam may need finger/hand dose monitors
(on finger tips/ring/wrist band)
Slide 22 - in the case of overexposure, describe the duty of the employer
The radiation employer must establish a radiation incident reporting procedure to include:
- what happened
- what caused the incident
- what is the extent of the dose / risk / harm to individual
- remedial action to minimise probability of similar incident occurring again
The employer must carry out a formal investigation in consultation with the RPA if a member of staff exceeds an ED of 15 mSv in a calendar year.
Any suspected overexposure, ie one in excess of any dose limit, must be investigated immediately and, if confirmed or not ruled out, must be notified asap to HSE, the employer, appointed doctor and individual concerned. Investigation reports must be kept for 2 years and , if overexposure is confirmed, for at least 50 years or until individual is aged 75 years.
Slide 23 to 29 - outline the ways in which exposure can be minimised
- time/distancing/shielding
- distance = standing back 30cm will reduce entrance dose by approx 50%
- shielding = lead aprons and in good condition (0,25mm Pb, 0.35mm Pb or 0.5mm Pb) Check condition every 6 months
- shielding = if you are near patient wear a thyroid shield and lead glasses
- protection from aprons relies on fit bc of partially unshielded organs etc
- frontal aprons are adequate for most
- wrap around aprons recommended for interventional radiology
- SHIELDING SCREENS = can reduced scattered dose by over 50x
Slide 31 to 34 - define “controlled area” and outline the general and minimum local rules that apply to such areas
- e.g. x-ray room/theatres/wards while equipment is in use if unprotected you must vacate
- local rules:
- description of controlled area
- arrangements to restrict access
- conditions for which entry is allowed for members of. public (carers etc)
- Safe working instructions
- Dose investigation levels
- Contingency arrangements for foreseeable radiation accidents
- Names of radiation protection supervisor
Slide 47 to 53 - explain the roles of the referrer, practitioner and operator in reducing risk for the patient
Referrer = supplies practitioner with adequate clinical info to enable the practitioner to justify the exposure
Practitioner = takes responsibility for the exposure and decides whether or not it is justified
Operator = person who carriers out practical aspect of the exposure such as radiographer
MORE THAN ONE PERSON CAN BE MORE THAN ONE DUTY HOLDER
tried descriptions of each role in terms of an x-ray
Employer = legally responsible person within an institution for providing a framework of procedures for medical exposures
Referrer = requests the X-ray examination
Practitioner = justifies the X-ray examination
Operator = undertakes practical aspects of the exposure
Slide 58 - describe the duties of a member of staff who has access to areas where ionising radiation is in use
- follow local rules
- not to knowingly expose themselves or others to radiation to an extent greater than necessary
- make full and proper use of PPE If provided and to report any defects and return to correct storage
- wear dosemeters if provided
- inform employer of suspected overexposure equipment malfunctions
