This is the fourth in a series of articles on radiation protection aimed at veterinary practice managers and others working in the field. The first article published in January was written by Paul Connolly outlined the background to radiation protection in veterinary practice including its legal requirements. The second written by myself and published in March dealt with its practical aspects including the main elements of an operational radiation protection process. The third, published in September, was written by Dave Hughes and covered the role of personnel monitoring in radiation safety programmes including the different methods for assessing operator doses. In this article I would like to outline ongoing and possible future developments in the delivery of cost effective support provided by your Radiation Protection Advisor (RPA) to help ensure that all legal requirements are fulfilled.
Mechanisms for RPA service delivery
Consultation, audit and review
For any work with ionizing radiations a radiation employer should consult with a suitable RPA in respect of compliance with IRR99. There are a number of ways that consultation might take place and it does not necessarily have to be face to face. However, matters about which an RPA should be consulted are outlined in appendix 2 of the Guidance Notes for the Safe Use of Ionizing Radiations in Veterinary Practice published by the British Veterinary Association. This includes:
- prior examination of plans for installations and acceptance of physical control measures of new (or modified) x-ray sources in relation to any engineering controls, design features, safety features and warning devices provided to restrict exposure
- critical examination of installer or supplier
- the periodic examination and testing of physical control measures and checking of systems of work
- implementing requirements as to controlled and supervised areas
- the formulation of local rules and written arrangements
- action to be taken should any member of staff exceed, or appear likely to exceed the formal investigation dose level
A very effective mechanism for consulting with an RPA on appropriate matters as well as demonstrating that such consultation occurs involves the use of an RPA Consultancy Audit, which employs a structured questionnaire aimed at assessing the effectiveness of the operational framework for radiation protection, which has been established by a veterinary practice. This type of approach to assessing the effectiveness or completeness of appropriate health and safety measures in force are employed routinely in many different sectors of activity (eg industrial, healthcare etc).
This approach to the assessment of radiation protection measures that are in force is ideally suited to a web based service delivery as outlined in figure 1. A structured questionnaire can be filled in on line by the veterinary practitioner and a report issued based upon the findings.
Equally plans for a veterinary x-ray room including the adjacent environment in terms of room usage, location of doors and windows, wall/barrier construction, occupancy factors can all be sent via e-mail or uploaded onto an appropriate web site for consideration by the RPA. Even digital images showing the location of an x-ray unit relative to its surroundings can be used to provide direct visual information. This approach reduces the need for an RPA to actually visit an establishment, together with the associated costs, in order to assess any specific radiation protection requirements. Such visits would only normally be indicated for unique situations or when other approaches indicate a visit would be necessary.
As indicated in the September article, one of the disadvantages of passive dosemeters (film badge, TLD etc), is they require returning to a processing facility for reading and it could be several weeks before the dose summary reports (and a potential issue) are received by the veterinary practice. Recently we have seen the introduction of a relatively low cost active dosemeter called ‘Instadose’ supplied by Mirion technologies. This device is similar to a USB pen drive and utilises an ion storage detector to measure personal dose.
This device and other similar devices have the advantage of being employed for periods of up to three years, thus eliminating the need to send and receive a new dosemeters every one to two months. They can also be read on a PC workstation, when the device is inserted into a USB port, provided the PC has internet access. The device allows a quick and easy reading to be taken with direct access to electronic reports. It also removes any time delay for processing, thus allowing employers to more readily demonstrate adherence to ALARP.
Often veterinary x-ray workloads are low so that service and maintenance visits by an x-ray engineer in order to service the x-ray equipment may only be required perhaps every 3 years. However, it is often desirable to demonstrate that x-ray equipment continues to function correctly more frequently. This can usually be demonstrated through the employment of a quality assurance (QA) programme, which assesses the performance of the equipment in order to highlight any changes that might have occurred in the intervening period between service visits.
Low cost QA programmes can be provided by means of a mailed QA pack. These consist of a number of TLD dosemeters that are exposed under predetermined conditions. The results of the dosemeter readings can be used to assess the accuracy of the kV settings, the x-ray output for specific exposure settings, tube filtration etc and checked for consistency over time. Results of such a programme may also be filed electronically on a personalised practice web site for easy access and review. Also, any changes in the x-ray equipment performance can be flagged up and fed directly to a service provider for attention.
Latest posts by Mike Moores (see all)
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- Future developments in radiation protection support to veterinary practice - May 22, 2013