Physical Agents Directive roundtable discussion
 The Society of Radiographers was party to the recent roundtable discussions convened by the Health and Safety Executive to discuss the impact of the European Union Physical Agents Directive (PAD) and the potential impact on MRI departments.
Kate Garas, SoR Professional Officer, reports that although the limit on static field strengths has been removed from the directive, and the RF field limit is averaged over the whole body and unlikely to impact on staff working in MR, there is still great concern regarding the time-varying gradient fields. These limits may prevent a worker standing close to the bore during imaging, and will seriously impact on interventional work or imaging using sedation or anaesthesia.
The directive has excited a great deal of concern with a cross section of interested parties, all of whom use MR. The HSE decided to hold the discussion to help manage its implementation by 2008. Participants ranged from MR manufacturers through to charity and research groups, taking in representatives from the RCR, IPEM, BAMMR, as well as the SCoR, and with a strong contingent from various government advisory bodies.
Frustration was expressed as to why the limits were being imposed with no real evidence of harm to workers. It was felt that the evidence used by the PAD was weak, not peer reviewed, and had been extrapolated from lower levels. Also it looked at effects that may occur within the central nervous system (CNS), whereas the body of the meeting felt that peripheral nerve stimulation. However, the HSE confirmed that it was unlikely that the directive would be overturned without hard research evidence to the contrary.
Kate Garas reports that the outcome of the day was that although it is possible that workers may exceed the limits for the time varying gradients, nobody actually knows because these values have not been specifically measured outside the bore of the magnet. The added complications are that they will vary depending on the gradients and the type of scan you are running. Additionally, the limits are different, head and trunk limits being lower than for extremities.
It was agreed that more research was needed to find out whether workers were exceeding the limits imposed and by how much. Measurements and mapping would need to be carried out on a number of different scanners, using worse case scenarios and this would take a good deal of time and funding. There is no obvious source of money available to fund this research.
A second audit was discussed to try and quantify how often a worker may be exceeding the limit by going too close to the bore during scanning, and this could be done using a snapshot questionnaire to departments. The BAMMR will discuss the possibility of undertaking this work, in conjunction with the SCoR.
Click for a pdf copy of the directive and the Society’s response. Back | Top | 
