ABSTRACT
As with all places of employment, nuclear medicine, medical physics and research departments in the United Kingdom which use radiation are required by legislation to make risk assessments associated with their work. Many have been slow to complete these, finding little guidance as to the best approach to take for departments which handle ionizing radiation. The Royal Free Hospital has set up a project to examine the whole procedure and approach to risk assessments in departments which use ionizing radiations, and has produced a standardized approach using matched risk assessment forms for both general risks and ionizing radiation risks. A worked example is included to illustrate the methodology and the standardized risk assessment forms.
Subject(s)
Nuclear Medicine/organization & administration , Radiation Injuries/prevention & control , Radiation Protection/methods , Risk Assessment/methods , Risk Management/methods , Safety Management/methods , Safety Management/organization & administration , Humans , Nuclear Medicine/standards , Occupational Exposure/prevention & control , Proportional Hazards Models , Quality Assurance, Health Care/methods , Quality Assurance, Health Care/organization & administration , Radiation Dosage , Radiation Protection/legislation & jurisprudence , Radiation Protection/standards , Radioisotopes , Risk Assessment/legislation & jurisprudence , Risk Assessment/standards , Risk Factors , Risk Management/organization & administration , Safety Management/legislation & jurisprudence , Safety Management/standards , United KingdomABSTRACT
Radiographs are taken in the neonatal period most commonly to assist in the diagnosis and management of respiratory difficulties. Frequent accurate radiographic assessment is required and a knowledge of the radiation dose is necessary to justify such exposures. A survey of radiation doses to neonates from diagnostic radiography (chest and abdomen) has been carried out in the special care baby unit of the Royal Free Hospital. Entrance surface dose (ESD) was calculated from quality control measurements on the X-ray unit itself. Direct measurement of radiation doses was also performed using highly sensitive thermoluminescent dosemeters (TLDs) (LiF:Mg,Cu,P), calibrated and tested for consistency in sensitivity. ESD, as calculated from exposure parameters, was found to range from 28 microGy to 58 microGy, with a mean ESD per radiograph of 36+/-6 microGy averaged over 95 examinations. ESDs as derived from TLD crystals ranged from 18 microGy to 58 microGy for 30 radiographic examinations. The mean energy imparted, the mean whole body dose per radiograph and the mean effective dose were estimated to be 14+/-8 microJ, 10+/-4 microGy and 8+/-2 microSv, respectively. Assuming that neonates and fetuses are equally susceptible to carcinogenic effects of radiation, which involve an overestimation of risk, the radiation risk of childhood cancer from a single radiograph was estimated to be of the order (0.3-1.3) x 10(-6). Radiation doses compared favourably with the reference values of 80 microGy ESD published by the Commission of the European Communities in 1996, and 50 microGy published by the National Radiological Protection Board in 2000.