New Recommendations for Occupational Radiation Protection

Abstract

INTRODUCTION Occupational radiation protection is a necessity whenever radiation is used. It is especially important for fluoroscopically guided and CT fluoroscopic procedures, in which occupational irradiation cannot be avoided. The International Commission on Radiological Protection (ICRP) publishes recommendations for occupational dose limits intended to limit the risk for stochastic effects to a level that is considered acceptable (ie, the dose limit denotes the value beyond which doses, and hence risks, would be generally considered unacceptable) [1]. In the United States, the ationalCouncilonRadiationProtecion and Measurements (NCRP) pubishes recommendations for maximum ermissible dose (MPD) that generlly, but not always, agree with ICRP ecommendations for dose limits [2]. egulatory bodies require that a orker not receive occupational exosure higher than the dose limits nd also require implementation of he principle of optimization of proection. The expectation is that occuational doses will be considerably ower than the dose limits. There are two types of occupaional dose limits in NCRP and CRP recommendations. The first rovides occupational dose limits for pecific organs or tissues. The second stablishes an acceptable risk level for ancer induction. Dose limits to orkers for exposure of part of the ody are expressed as equivalent ose for tissue (deterministic) efects in an organ or tissue and as ffective dose for stochastic effects hroughout the body. Effective ose is intended to be proportional to the risk for radiation-induced cancer. In the United States, Nuclear Regulatory Commission regulations provide specific requirements for personal dosimetry when using radionuclides. When x-rays are used, the Occupational Safety and Health Administration and state regulations provide corresponding requirements. Different radiation quantities and units are used in these different regulations. For consistency, we use the ICRP notations for radiation quantities and units (Table 1) [1]. Unfortunately, the SI unit for both equivalent dose and effective dose is the sievert. Readers of the regulations and the literature need to be aware of the context in any particular situation.