20.4.1 Verification of the Usability
As a method of using this system, before cooking any meal or buying any ingredients, one can enter the system from a personal computer or a smart phone, enter the meal ingredients one has access to. By doing this, one will estimate the intake. This way allows obtaining the history of radioactivity intake and estimates the information about the intake of internal exposure dose, so one can make the decision to reduce the amount to eat/not to eat something if it is not suitable/eat everyday or occasionally/not eat at all/so from that previously ingested data the user can decide what and how much to eat or not. When the user ate it, the information is kept in history and becomes the basic judgment criteria for the meals eaten after. Thus, this system can be considered to contribute to the “recovery of the right to self-determination” and is expected to help residents to regain confidence by managing their day-to-day intakes.
Then, as the present system has been constructed keeping in mind the assessment capabilities of the original CORPORE, it is also applicable for reverse utilized assessment. Therefore, it can be used not only in Japan. In fact, we asked the original CORPORE development team to trial this system, and it was highly evaluated. It was also announced to be easier to use than the “original CORPORE because it is only necessary to input each dish, and not each food ingredient as originally and this is obviously more realistic for the Japanese context,” “Because ETHOS and CORE activities in Belarus started 10 years after the accident, Cs-134 was ignored in CORPORE given its very small influence at the start of the project. In Japan, the accident has just happened so the knowledge about short nuclides in their half-life corresponded to the multi-nuclides is extremely valuable.”
Also, it became possible to handle the natural origins of radioactivity information from the previous self, and to perform the management of global radioactivity uptake.
The number of food products is 1,199,241, which is integrated in the product database. The levels of 1,113,931 products of them (92.8 %) are under the detection limit value. Among them the number of food products added from January to March 2015 is 67,401, among them 65,117 (96.6 %) are about the detection limit value or less, equal to or greater than the limit value (Table
20.1) of the food makes 145 (0.2 %) of cases. For the 145 ingredients of the limit value or more see Table
20.2. The percentage of foods with the limit value or more is very little, mostly it is wild boar meat, but because black bear meat and Japanese deer meat is not common in a general household it is hardly applicable as a food ingredient for Japan. It can be said that the majority of Japanese people at the moment are hardly affected by this food. However, easy evaluation tools are required in contaminated areas for evaluation and the understanding of the situation. These tools will help to develop the radiation protection culture to individuals allowing them to have a grip on their own protection.
Table 20.1
The reference levels of foods in Japan (Notice No. 0315 Articles 1 of the Department of Food Safety, March 15, 2012)
Water | 10 |
Soft drinks | 10 |
Tea for drinking | 10 |
Milk | 50 |
Foods other than above | 100 |
Table 20.2
A breakdown of the products positive at levels exceeding limits between January 1st and March 31st 2015 in the product database
Wild boar meat | 116 |
Japanese deer meat | 10 |
Asian black bear meat | 5 |
Copper pheasant meat | 3 |
Japanese stingfish | 3 |
Iwana mountain trout | 5 |
Landlocked masu salmon | 1 |
Mushroom powder | 1 |
Stone flounder | 1 |
Moreover, these tools are urgently required in this situation, and it is essential to prepare and keep them in order in case of future contingencies.
20.4.2 Subject of Future Investigation
The system is made to favor the development of the radiation protection culture of people in contaminated areas and its neighborhoods; it will be one of the tools of reconstruction of their living environment, so it is necessary to consider this system for the future.
This system estimates the amount (Bq) of radioactivity that was ingested by using the mechanism of CORPORE, visualizes the state of users’ history, and helps to show the discharged radioactivity as a graph. However, the residents of contaminated areas want to know how much of the exposure dose (mSv) they receive and the ingestion part of it. In the future, it will be necessary to establish a mechanism for displaying the conversion of the level of contamination (Bq) into the internal dose (mSv) by using a conversion coefficient of each species that is provided by the ingested amount of radioactivity of the ICRP Publication 72 [
13].
Although inputting cooking information is available and there are cooking information templates to be obtained from a recipe site to make the input easier, it is still a hard work to manage each meal every day. We want to consider the ways to make this process even easier. For example, we consider making it possible to identify food from a photograph of the cooking or the supermarket receipt and POS information of shopping to guess the food.
For determining the amount of the radioactivity ingested, the food eaten by the user might not be available in the food database, and does not correspond to any food measurement results; even if it is unknown it still may be sufficient. We do not consider the radiation level to be 0 but wait a month and build a graph of the uptake potential calculating it from the maximum value and the minimum value of radioactivity in food of the predetermined period on the food database width, or ingenuity, such as displaying the value of the radioactivity survey conducted before the accident [
14]. In this regard we think it is necessary to pursue the reflection on the best way to proceed.
As mentioned earlier, the results for Cs-137 and other nuclide species are not currently integrated into the database structure to correspond to the multi-nuclide variety. This not only concerns nuclides which are listed in the radioactivity measurement results of the MHLW, but also the internal exposure control is possible by ingestion of natural radionuclides by incorporating models such as potassium 40 and polonium 210.
Also, due to the use of a computational model of the original CORPORE calculation system, used in the European context, we would like to consider the comparison method and use of the computational model with accordance to the Japanese data only.
Then, from the original CORPORE development team we receive an opinion that “since the genre of diet became different we want to be able to compare the exposure situations. Separating the diet patterns will help to make groups in the future automatically.” For example, seafood diet group, agricultural group, etc. will help to build a kind of patterned templates for further study, and can increase the number of subgroups in each group such as according to gender or regions for future statistical data. In this paper, the system was evaluated by experts. The evaluation by residents is also required to evaluate the actual usability. We intend doing it in the future.
In addition, after the nuclear accident, there was an increasing interest in medical exposure; the efforts have become more active for the medical exposure dose management [
15‐
17]. Also, Dose Structured Report was defined in DICOM as a standard for radiation exposure information management for medical exposure [
18], while we are in the environment, which is easy to collect the information of the medical exposure.
As it is described above, in the present situation the influence of internal exposure from food is almost negligible for a large number of individuals although it is of concern for the residents and could be sensitive for specific groups of population consuming home-grown products and products from the forest. The impact of external exposure from the surrounding environment is considered to be potentially larger depending on the area as well as on the individual habits and activities. External exposure data have been gathered in the Prefecture health survey in collaboration with dose assessment [
19]. In the future we consider building a system that can manage all the radiation exposures (including medical exposures) of the individual, with the main purpose to develop the radiation protection culture.
In addition, radiation dose information should not only be managed, but also the day-to-day nutrition management and health management could be considered also, with a unification mechanism where individuals can add nutrition information on food. Furthermore, it is expected to be also applicable for the management of the body accumulation of toxics such as arsenic and heavy metals and not only radioactivity.