Occupational exposure and radiation protection in the medical field -non-uniform exposure management of medical staffs

In medical field, radiation is used for various examinations and treatments. The number of radiological examinations has also increased internationally. Radiation is regulated by laws in each country in order to secure the safety of workers and the public in effective use. As a recent trend in occupational exposure, the International Commission on Radiological Protection (ICRP) has issued a statement to lower the equivalent dose limit of the crystalline lens of the eye to 20 mSv per year on average for five years. They released their scientific basis at ICRP Publication 118. From this statement, there is an increasing interest in the lens exposure in the medical field, its evaluation, and protection methods. In recent years surgical imaging machines used in surgery have become widespread. The use of radiation outside the imaging diagnosis department has increased, and radiation management of patients and radiation workers has been taken up in ICRP Publication 117 as a problem. This paper reports on the current situation of exposure of radiation workers at medical fields and how to manage them.