Trends and Distribution Analysis of Occupational Exposure from Medical Practices in China (2010-2016).

Occupational exposure to ionizing radiation from medical practices in China has been collected for a 7 y period between 2010 and 2016 from roughly 220 individual monitoring service providers through the Chinese Registry of Radiation Workers. Statistical dose distributions and characteristic tendencies are presented based on the evaluation in terms of six occupational categories. A reduction can be seen in average annual effective dose for interventional radiology, nuclear medicine, diagnostic radiology, radiotherapy, dental radiology, and others by 52%, 47%, 46%, 34%, 69%, and 31%, respectively, for the 7 y period. More than 94.5% of radiation workers received annual doses less than the public dose limit (1 mSv) in 2016. Workers engaged in nuclear medicine and interventional radiology activities were found to receive relatively more dose than the other fields of practice. Diagnostic radiology makes the dominant contribution of 68% to the collective effective dose of 73,641.3 person mSv received by 211,613 radiation workers in medical practices in 2016. The observation of workers in medical practices receiving well below the recommended occupational dose limit (20 mSv) could be a result of an improvement in radiation protection practices in the medical field in China. However, it is still necessary to control and manage the workplace and radiation workers to avoid unnecessary exposures, in particular for the workers engaged in nuclear medicine and interventional radiology activities.