Trends of Annual Whole-body Occupational Radiation Exposure for Industrial Practices in China (2009-2018).

The national status and dose trends on the occupational exposure to ionizing radiation in industrial practices for 2009-2018 in China are presented in terms of seven occupational categories. A total of 504,538 industrial radiation workers were monitored for the period 2009-2018, with a continuous increase in the number of workers from 23,789 in 2009 to 66,017 in 2018. The annual average effective doses were 0.399, 0.425, 0.392, 0.376, 0.346, 0.355, 0.312, 0.305, 0.270, and 0.230 mSv from 2009 to 2018, respectively, which were well lower than the recommended occupational dose limit of 20 mSv y-1 for radiation workers. The Mann-Kendall test result shows a statistically significant decreasing trend at a rate of 0.02 mSv y-1 in average annual effective doses (p<0.001). In addition, more than 95.4% of radiation workers in industrial practices received an average annual effective dose less than the public dose limit of 1 mSv. It was also found that the average annual effective doses in industrial radiography and well logging were significantly higher than those in five other categories (p<0.001). Based on these observations, it is still necessary to control and manage the workplace and radiation workers to control occupational exposure as low as reasonably achievable, especially for the workers engaged in these two activities.