Dr. Tsubokura's Radiation Lecture Vol.134
Author: Masaharu Tsubokura PhD.
Editors: Akihiko Ozaki M.D.,PhD., Yuki Senoo
267. Efforts to minimize occupational radiation exposure
March 8, 2020
Occupational exposure refers to ionizing radiation exposed during the performance of one’s duties. Occupational groups that are routinely exposed to radiation include coal miners, who are usually working in high-natural-radiation areas, airline crews, workers at nuclear power plants, physicians, nurses, and radiology technicians.
Exposure from manmade radiation accounts for approximately 10% of total occupational exposure, and the majority of it is caused by medical radiation exposure, which corresponds to radiation received from health care professionals, such as physicians, nurses, and radiology technicians when they are performing examinations and treatment using radiation.
According to previous evidence, radiation technicians tended to receive higher doses of radiation exposure than physicians and nurses did, and health care professionals working at general hospitals tended to receive higher doses of radiation exposure than those working at university hospitals or clinics did.
In any case, the overall average of annual radiation exposure among health care professionals usually did not exceed one millisievert. In contrast, the proportion of health care professionals with annual radiation exposure exceeding 20 millisieverts was highest among physicians (one in 2000). Of these physicians, some were reported to have received radiation exposure exceeding 50 millisieverts.
In addition, for furthering developing medical equipment, it is crucial to reduce occupational exposure by sharing knowledge as well as improving the work environment and protocols.
268. Challenges reflected in a health survey of workers
March 15, 2020
Occupational exposure refers to exposure to ionizing radiation during the performance of one’s duties. Occupational groups that are routinely exposed to radiation include coal miners, who usually work in high-natural-radiation areas, airline crews, workers at nuclear power plants, physicians, nurses, and radiology technicians.
Naturally, the radiation exposure of the workers at the Fukushima Daiichi Nuclear Power Plant, who were required to engage in radiation work immediately after the 2011 accident, was also considered to be occupational exposure, regardless of its urgency.
According to a report that the United Nations published in 2013, the average exposure dose over a period of 19 months after the Fukushima nuclear accident among workers at the Fukushima Daiichi Nuclear Power Plant was approximately 10 millisieverts. Hoverer, it was also reported that 0.7% (173) of the workers had exposure doses exceeding 100 millisieverts. Of these workers, the maximum exposure dose was 679 millisieverts. A large gap exists between the average exposure dose of workers at the nuclear power plant after the nuclear accident and that of the general population. The report also states that the exposure doses of the workers estimated in the report were based on measurements performed during the early phase of a post-nuclear accident in a time of turmoil, and therefore, further investigation is required before confirming the conclusion.
Routine health checkups have been conducted for workers at the nuclear power plant since the 2011 Fukushima nuclear accident. However, several issues surround these routine health checks; these include, for example, eligibility for health checkups and problems regarding long-term follow-up and adherence to them.
The Japanese version of the manuscript was originally published in Fukushima Minyu, a local newspaper in Fukushima prefecture, Japan, 8 March and 15 March 2020 was reproduced for MRIC Global under the author's permission.