Risk communication regarding radiation exposure by experts using two concepts of regulatory science and ALARA

In the Tohoku region of Japan, risk communication programs on radiation exposure are of great importance, especially with respect to reducing the stress and anxiety among those affected by radiation exposure. Although the concepts of ‘as low as reasonably achievable’ (ALARA) and regulatory sciences (RS) were very important for the smooth operation of risk communication among a wide range of stakeholders, our previous research showed that only 23.5% and 16.5% of medical doctors in Japan had an accurate awareness of them, respectively. To make risk communication more effective, this study examined the levels of awareness of the concepts of ALARA and RS among academic experts in Japan and compared their level of awareness of technical terms regarding radiation to that of the expected level for a layperson. This study also showed that, even among faculty working at graduate schools in Japan, only 29.8% and 39.4% had an accurate knowledge of ALARA and RS. To improve the knowledge of laypeople and experts on these concepts, they should be added to the primary education curriculum. This study demonstrated that among experts in many academic fields, a significant range of estimates existed of lay knowledge of technical terms regarding radiation. The highest scores were assigned by faculty in the field of humanities. Thus, before conducting risk communications, experts from all fields should identify the expected level of awareness among laypeople on the topic. In addition, risk communications regarding radiation should be conducted by academic experts and healthcare professionals together with facilitators or lecturers.


Introduction
March 2011, the Great East Japan Earthquake hit the Tohoku region of Japan, causing a major accident at a nuclear power plant. Reporting by the Japanese Reconstruction Agency as of March 2022 indicates that 37 000 evacuees are still unable to return to their homes in Tohoku due to the incomplete reconstruction [1]. Immediately following the disaster, a range of stakeholders in Tohoku released risk communications for residents in the devastated region. In particular, doctors, nurses, and pharmacists, along with other healthcare professionals, have been taking part in risk communication.
The efficacy of risk communications has previously been evaluated in terms of possibilities of enhancing the effectiveness of risk communications that followed the Great East Japan Earthquake in Tohoku [2][3][4][5][6]. The authors of this article previously conducted research on the evaluation of risk communication and the degree of awareness of technical terms regarding radiation in six prefectures: Fukushima and Miyagi, which were hardest hit by the Great East Japan Earthquake and the consequent damage; Hiroshima and Nagasaki, which had been hit by atomic bombs; and Tokyo and Aichi, as controls [7]. We found that Fukushima Prefecture, followed by Miyagi Prefecture, had a significantly higher level of understanding than Aichi Prefecture, and we also found reported that residents in the disaster-stricken areas had obtained the necessary information and were proactive about their understanding of risk.
We also found that the two abbreviations, 'as low as reasonably achievable' (ALARA) and regulatory sciences (RS), are central for smooth risk communication. However, we also found that medical professionals, including doctors as instructors, did not understand these two concepts very well [8].
The International Commission on Radiological Protection defines ALARA as 'the principle of optimization of protection: the likelihood of incurring exposures, the number of people exposed, and the magnitude of their individual doses should all be kept as low as reasonably achievable, taking into account economic and societal factors' [9]. Because ALARA takes into account economic and social factors, it has attracted some controversy regarding its effectiveness. With reference to the experiences of the Fukushima Daiichi Nuclear Power Plant accident, the International Radiation Protection Association has found that ALARA is a globally accepted concept, and the principle of optimization is a central dogma for radiation protection, as well as being the most important factor in avoiding radiation exposure [10].
In 1987, Dr Mitsuru Uchiyama proposed the concept of RS, which refers to a fit with the technological and scientific accomplishments of a community. This concept is used in establishing standard values from the perspective of current scientific and technological accomplishments. Recently, RS has come into wider use globally as a key concept that defines how much risk can be tolerated within the range allowable by safety regulations in areas of risk, especially in the field of drug approval regulations [11,12].
In risk communication in Japan, both healthcare professionals and experts in a range of academic fields play crucial roles in the communication of risk as instructors and/or counselors [13]. This study examined the level of awareness of ALARA and RS by experts in academia. It also investigated differences among experts with respect to the layperson's awareness of 20 medical terms regarding radiation and experts' perceptions of needs for the public in risk communication to compare this with the needs of the public.
This study is the third of three in a sequence making up a larger study.
The title of the first study was 'Level of perception of technical terms related to the effect of radiation to human body by residents of Japan,' conducted from 13 to 19 February 2014 [7]. Demographic data pertaining to the residents of Miyagi, Fukushima, Tokyo, Aichi, Hiroshima, and Nagasaki Prefectures were the subjects of this study. A sample size of 160 was determined for each prefecture. The highest recognition levels were reported by respondents from Fukushima (17 items). Those from Miyagi had the second-highest levels (10 of 17 terms); the second-highest recognition levels for the remaining seven terms were marked by the respondents of Tokyo. Respondents in the Tohoku region had superior recognition of the technical terminology relevant to the effects of radiation on the human body.
The title of the second study was 'Medical staff perceptions of risk communication needs for the public and comparison with the needs expressed by the public' [8]. Demographics were collected from doctors, pharmacists, and nurses from all over Japan and compared to the data gathered from laypeople from the first study. In total, 170 medical doctors, 84 pharmacists, and 246 nurses were selected from all over Japan from 12 to 17 August 2016. The results showed differences between the public perception of risks and what the belief in the perception of risk was among medical workers. Only 23.5% and 16.5% medical doctors had an accurate perception of ALARA and RS in Japan, respectively.

Study population and design
On 14 July 2016, this study was approved by Shubun University Ethics Committee prior to conducting research (approval number: 28SR2). The research was conducted through a contract with NTT Com Online Marketing Solution Co., Ltd, using an internet survey maintained by them. The monitors were registered with an internet survey company, along with basic information, including their gender, location of residence, and so on.
In total, 104 faculty members of graduate schools, 169 faculty members of universities, 58 teachers of college/vocational schools, and 1094 laypersons were selected from all over Japan, making 110% of the total amount intended. A two-step method was used to collect data from the experts. After excluding imperfect samples (as assessed by the contracting survey company), the results of the questionnaires were submitted to us. The research period was 7-27 August 2018.

Questionnaires and analyses
Questionnaires were composed incorporating respondent demographic information, how often the respondent had participated in a risk communication regarding the effects of radiation on the human body, the respondent's level of awareness of 20 medical terms related to radiation, the level of awareness of the meanings of eight medical issues related to radiation, the necessity of knowledge to be shared in risk communications, information sources related to radiation, and the practitioner's assessment of the reliability of the layperson and the reliability of the government of Japan, followed by information on risk avoidance behavior related to radiation.
The scoring of the answers was given on a scale of 1-5; for questions related to the respondent's own knowledge, for instance, the scale included 1, 'I have no idea'; 3, 'I cannot say for sure whether I know'; and 5, 'I know very well.' Table 1 presents the demographic information of the respondents. First of all, a statistically significant difference in age was seen between male and female faculty. Statistically significant differences were also observed across disciplines between male and female faculty at graduate schools, as well as between male and female teachers at college/vocational schools. A statistically significant difference also existed in age and education between male and female lay individuals.

Results
With reference to factors related to the awareness of the ALARA across experts and laypersons, based on the unadjusted results of the analysis, a statistically significant association was observed with respect to having knowledge, as seen in table 2. Those who were male and a faculty member of a graduate school, or a faculty member of a university, were more likely to 'know,' compared with those who were female, and a layperson (OR = 1.943, 95%CI 1.302-2.901, p = 0.001; OR = 4.737, 95%CI 2.954-7.597, p = 0.000; OR = 2.606, 95%CI 1.676-4.050, p = 0.000, for female and laypersons, respectively). After adjusting for gender, age, and lay or expert status, also male, and a faculty member of a graduate school, and a faculty member of a university was related with a significant association with 'know' (adjusted OR = 1.761, 95%CI 1.150-2.698, p = 0.009; adjusted OR = 3.833, 95%CI 2.348-6.259, p = 0.000; adjusted OR = 2.366, 95%CI 1.512-3.701, p = 0.000) compared with female and laypersons as references, respectively.
In our previous work, we evaluated the contexts 'by doing risk avoidance behavior based on the criteria made a definition by the government, citizens can correctly avoid health impacts,' and 'considering the uncertainty of risk assessment, citizens should prevent risk on their own in the case of the Great East Japan Earthquake' for healthcare professionals and laypersons. We also collected data on the abovementioned contexts. For 'by doing risk avoidance behavior based on the criteria made a definition by the government, citizens can correctly avoid health impacts,' in an unadjusted analysis, a statistically significant association existed between "agree" and, with among "Layperson or Institute of Experts" as shown in table 4. Professors at graduate schools were more likely to 'agree,' than laypeople among those who were faculty members (OR = 1.674, 95%CI 1.085-2.583, p = 0.020). After adjusting for gender, lay or expert status, only faculty of graduate schools had a significant agree response (adjusted OR = 1.679, 95%CI 1.075-2.623, p = 0.023, for female and a layperson, respectively). For self-risk avoidance behavior related to the Great East Japan Earthquake, in the unadjusted analysis result, no statistically significant associations existed with responses of 'agree' (data not shown). Table 5 presents the differences among ten knowledge items shared in risk communication; four of the ten were significant. For instance, a statistically significant difference appeared among graduate school faculty, university faculty, college/vocational school instructors, and laypeople with respect to the highest, and 3-5 awareness levels out of ten aspects, such as 'scientific facts, effects of radiation on children, providing the basis for standards, and validation of standards.' Knowledge of scientific facts was claimed by 82.7%, 81.1%, 69.0% and 65.4% of faculty at graduate schools, faculty at universities, instructors at college/vocational schools and laypeople, respectively. The knowledge of the effects of radiation on children, was claimed by 74.0%, 69.8%, 62.1%, and 61.7% of the same groups, respectively. The knowledge of setting rules for standards was claimed by 75.0%, 71.0%, 67.2%, and 62.5% of the same groups, respectively. Knowledge of validation of standards was claimed by 76.9%, 69.2%, 65.5%, and 62.3% of the same groups, respectively. Table 6 showed statistically significant differences for one of the eight information sources related to radiation among respondents: 64.4% of faculty of graduate schools took academic journals/technical books to be a resource, followed by the internet (43.3%), forum/meeting style of risk communication (44.2%),     Regarding factors related to laypeople's expected level of awareness of 20 medical terms related to radiation, in the unadjusted analysis, a statistically significant association existed with the expectation that a layperson would know this term in table 7. Experts in humanities were more apt to think that a layperson would know than those who were experts in natural science (OR = 2.781, 95%CI 1.314-5.883). After adjusting for gender, age, institute of experts, and field of expertise, the field of humanities showed a significant association with the judgment that a layperson would know (adjusted OR = 2.910, 95%CI 1.317-6.428, p = 0.008). most appropriate number from 1 to 5 was selected and was termed 'the sources of information regarding radiation and its reliability and the reliability of the central government and risk avoidance behavior regarding radiation.' For the analyses, 4 and 5 indicated 'I agree' . and 5 out of 1-5 were used as 'I know.' To evaluate the crude odds ratio (OR) and adjusted OR in terms of the awareness of level of a layperson's awareness of the 20 technical terms regarding radiation among experts, the five-point Likert scores of 20 medical terms were totaled, and 61 was used as an index of cut-off, in order that a total score ⩾ 61 for level of awareness of 20 medical terms related to radiation represented that 'a layperson knows.' The 20 technical terms regarding radiation are as follows; x-ray, radioactive substance, WHO (World Health Organization), radioactive cesium, external radiation exposure, internal radiation exposure, IAEA (International Atomic Energy Agency), Sievert, half-life, Becquerel, acute radiation exposure, radioactive strontium, natural background radiation, low-dose radiation exposure, α-ray, β-ray, neutron ray, γ-ray, the law concerning the prevention of radiation hazards due to radioisotopes and others of Japan and ICRP (International Commission on Radiological Protection). b Crude odds ratio and 95% confidence interval. c Adjusted odds ratio for gender, age, occupation, Participation of clinical trial and 95% confidence interval.
N: number of subjects.
With respect to the layperson's expected level of awareness of the meanings of eight medical issues related to radiation by experts, in the unadjusted analysis, no significant differences were found based on socio-demographic parameters (data not shown).

Discussion
Both ALARA and RS are very important for effective risk communication among many kinds of stakeholders. However, our previous study demonstrated that only low percentages of medical doctors in Japan had a correct awareness of the concepts of ALARA and RS, 3.5% and 16.5%, respectively [8]. The results of this research demonstrate that even faculty at graduate schools in Japan, experts in many kinds of fields, have an insufficient knowledge of ALARA and RS. Only 29.8% and 39.4%, respectively, had an adequate knowledge of ALARA and RS. Therefore, to rectify this, both experts or healthcare professionals and laypeople should receive instruction on these concepts in primary education, accompanied by plain explanations.
In total, 32.7% of graduate school faculty agreed that 'by doing risk avoidance behavior based on the criteria made a definition by the government, citizens can correctly avoid health impacts,' showing a statistically significant difference among experts and laypersons. No statistically significant difference was seen between experts and laypersons with respect to the item 'in considering the uncertainty of risk assessment, citizens should prevent from the risk at their own risk in the case of the Great East Japan Earthquake.' In contrast, our previous study showed that about one fifth of healthcare professionals and laypeople agreed that 'by doing risk avoidance behavior based on the criteria made a definition by the government, citizens can correctly avoid health impacts' [8]. A statistically significant difference existed in the self-risk avoidance behavior related to radiation. The highest percentage (54.0%) were identified by laypeople, in relation to 'considering the uncertainty of risk assessment, citizens should prevent from the risk.' Even among experts in healthcare and academia, the reliability of central government showed different aspects. Therefore, both should collaborate as facilitators and/or lecturers on the same forum-style risk communications.
Lochard noted that dialogues regarding radiation exposure were focused on the interest of the public and not on what the healthcare professionals considered to be the public interest [14]. This implies a difference between the groups. In relation to knowledge that should be shared in risk communications based on the results of this study, the highest-interest item for laypeople was the risk of radiation effects (68.6%), followed by scientific facts (65.4%), effectiveness of food standards against radiation effects (65.3%); among the ten items, the uncertainty of radiation effects (55.2%) was the least interesting. Our previous work also indicated that for the layperson, the uncertainty of the radiation effects was the least interesting, possibly because laypeople tended to report that uncertainty produced anxiety [8]. On the other hand, graduate school faculty thought that of most interest to the public was scientific facts (82.7%), followed by standards validation (76.9%) and setting rules for standards (75.0%). University faculty thought that scientific facts (81.1%) were most interesting, followed by setting rules for standards (71.0%). College/vocational instructors thought that of most interest was risk of radiation effects (74.1%), followed by effectiveness of food standards against radiation effects (70.7%). These results demonstrate that there were important differences between the public perception of risks and experts' belief in what the public's risk perception was. This study also demonstrated that experts should consider whether dialogue regarding radiation exposure is focused on the interest of the public to produce the most effective risk communication.
Hidaka et al found that the 'acquisition of correct knowledge of working environment management was related with anxiety over radiation exposure. The acquisition of the knowledge may help the reduction of physical health risks, it may even increase the mental health risk' [15]. That is, these seem to be risk explanations rather than risk communications. Following these findings, facilitators should take these differences into account when engaging in risk communication with the public.
Among graduate school faculty, academic journals and technical books were the most trusted source, followed by forums/meetings for risk communication and television. Additionally, academic journals/technical books, and risk communication had the highest values in terms of reliability. However, the reliability of academic journals/technical books (74.0%) among graduate school faculty was far from 100%, perhaps implying some skepticism among experts.
On the other hand, the reliance on academic journals/technical books among graduate school faculty is higher than among university faculty and college instructors. It seems that faculty of graduate schools were more familiar with accessing academic journal/technical books than university faculty, and college instructors. Our previous study showed that medical doctors responded similarly [8]. Experts and medical professionals should explain the necessary information to laypeople in the most concise and plain, but scientifically sound, way.
Academic experts in the humanities in academia exhibited the highest estimation of lay knowledge in terms of technical terms regarding radiation, with a statistically significant difference. Our previous study showed that medical doctors tended to overestimate lay knowledge of medical terms related to radiation relative to pharmacists and nurses [8]. In contrast, nurses were more likely to estimate that a layperson would know medical terms not related to radiation than pharmacists and medical doctors were [16][17][18].
Regarding communication between the patient and healthcare professionals, Hu called for a strategy to improve patient-provider communication and trust to improve patient acceptability of uncertainty in clinical work. Therefore, many fields' experts should check the awareness level of a layperson on a topic before engaging in risk communication [19].
Although web surveys are widely used in the medical sociology field in Japan, information related to the level of awareness of medical terms might not be obtained in an optimal way through a web survey compared with an interview survey. This is a limitation of this study, therefore.
Moriyama et al found that effective support increased the trust of older residents of restoration shelters regarding the involvement of scientists, including healthcare workers, in risk communications [20].
In conclusion, to improve knowledge of ALARA and RS among both experts/healthcare professionals and laypeople in Japan, the two concepts should be taught in the primary education curriculum with plain explanations. In addition, before conducting risk communication, all experts should endeavor to check the level of awareness of the topic among their lay audience.

Data availability statement
All data that support the findings of this study are included within the article (and any supplementary files).