Regulations and legal responsibilities Flashcards
What is ionising radiation?
Has the ability to knock electrons (free radicals) out of cells in our body which can go on to cause further damage etc. to our DNA
e.g. xrays, gamma rays etc.
In which two ways does ionising radiation damage DNA?
- Indirect = generation of free radicals
- Direct = interaction with DNA
What are the two types of effects of ionsing radiation?
- Stochastic effects
- Non-stochastic effects
What are stochastic effects?
Those for which the probability increases with dose, without threshold (every exposure carries the possibility of causing damage and the severity is not dependent on the size fo exposure)
E.g cancer induction & heritable effects
What are non-stochastic effects?
Those where the incidence and severity are proportional to dose (i.e. definitely occur from a specific high dose of radiation) = has a threshold dose
e.g. Mucositis, loss in taste, dry mouth, ‘radiation caries’ -> by gingival margin due to dry mouth, tooth defects if irradiated while teeth developing, atrophic mucosa, cataracts, radiation burns, sterility
N.b. DOSES USED IN DENTISTRY ARE TOO LOW TO CAUSE THIS KIND OF EFFECT
What does the International Commission on Radiological protection (ICRP) do?
Produce advice for the creation of national legislation to govern the use of ionising radiation
e.g. consider how we can reduce harm to the environment from xrays
Radiography in dentistry:
Whats the dose and volume like?
Low dose but high volume (overall population dose high)
2008 - estimated 17,800,000 intraorals & 2,700,000 DPT’s were taken
What % of radiographs submitted to the dental practice board (DPB) audit were of unacceptable quality?
18%
What is the problem of unacceptable quality radiographs?
= ineffectual = needs repeating
(increases exposure to patient)
What is the risk benefit ratio?
If something causes harm (i.e. exposure to ionising radiation) then the good must outweigh the bad
What is the UK background dose of radiation?
Approx. 2.5 mSv
What is the radiation dose of a DPT?
Approx 0.002 Sv
n.b. this depends on technique and machine being used
What is the radiation dose of a single periapical?
Approx 0.001mSv
What are the different UK legislations of radiography?
- Ionising radiation regulations IRR (1999)
- Ionising radiation [Medical exposure] regulations IR[ME]R (2000)
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What are the legal obligations of an individual taking radiographs etc.?
To keep:
- The general public safe (IRR)
- Staff safe (IRR)
- Patietns dose as lower as reasonably possible [ALARP] (IR[ME]R)
What does the Ionising Radiation Regulations (IRR) relate to?
The workplace, employees and the public
= the responsibility of the employer
= A framework ensuring exposure to ionising radiatin arising from work activities is as low as reasonably practicible (ALARP) and does not exceed specified limits
What 10 things does the Ionising radiation regulations (IRR) require?
- Risk assessment
- Employers written procedures
- Appointment of radiation protections advisor (RPA) & radiation protection supervisor (RPS)
- Local rules (contingency plans)
- Controlled areas
- Restriction of exposure (design, systems of work and PPE)
- Quality assurance programme (routine inspections & testing of equipment)
- Dose limits
- Dose constraints for comforters and carers
- Notification of equipment related incidents
What happens in a risk assessment (5 steps)?
- Identify the hazards (i.e. dose)
- Decide who may be harmed & how they may be affected
- Evaluate the risks (i.e. likelihood) and implement control measures
- Record the findings
- Periodoic review and revision of risk assessment = Standard operating procedures (SOPs)
Who is a radiation protection adviser?
Each dental practice MUST have one - this appointment must be in writing (not neccessarily on site all the time)
Must be consulted on for:
- Requirements for controlled areas
- Prior examination of plans for new equipment and rooms
- Regular calibration of dose monitoring equipment
- Periodic testing of safety features and warning devices
- Risk assessment and contingency plans
- Involved in staff training on safe use
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Who is a radiation protection supervisor (RPS)?
Usually a dentist/dental nurse who must be on site
Each practice must have one
Need adequate training & sufficient authority to implement their responsibilities = ensure local rules are followed