Status and Trend of Occupational Radiation Exposure in Radiotherapy and Diagnostic X-ray Practices in Bangladesh

Introduction: The evaluation of occupational exposure and related trends due to external ionizing radiation in diagnostic and therapeutic purposes has become crucial to understanding the implementation of regulatory acts and technological advancement. This study describes the status of occupational radiation exposure in the radiotherapy (RT) and diagnostic X-ray (DR) sector and the comparison with related research. Material and Methods: Overall, 12141 radiation workers were monitored using thermoluminescent dosimeters (TLDs) read-out by Harshaw TLD Reader (Model 4500) on a quarterly basis. Several parameters such as annual collective effective dose, average annual effective dose, collective and individual dose distribution, and the probability of cancer risk were analyzed. Results: The number of monitored workers increased by around 35%, whereas the number of radiation workers who received a measurable amount of doses decreased by around 37% during 2014-2018. The annual average effective doses in RT and DR were in the range of 0.017-0.1112 and 0.076-0.1702 mSv, respectively. The results indicate that more than 94% of the total collective dose was for the non-physician group. Among exposed radiation workers, almost 78% received doses below 1mSv and <1% received doses over 15mSv. The annual average effective dose is five times lower than the worldwide average value. Depending on the average occupational dose, the expected number of radiation-induced cancer cases among the monitored workers is below 1. Conclusion: Dose distribution tends to move towards lower levels and reveals that the majority of the organizations maintain adequate radiation protection.