(12) In the Conclusion section, the authors write “it is possible to predict the external exposure dose received by each individual based on the aircraft monitoring data”. As we pointed out above, individual fluctuations of the coefficient are not taken into account in drawing such a conclusion. The conclusion of this paper cannot be a basis of radiological protection.
To summarize all the issues (1)–(12) above, the treatment of data in the paper does not satisfy the minimum standard required for scientific papers. For instance, it is even unclear whether the main conclusion “c = 0.15” represents the average or the median of the actual data, and the number of samples excluded as outliers is not specified. Given that the exposure dose is known to follow the log-normal distribution, there should be no need
to exclude part of the samples as outliers if the logarithm is taken in the first place. As observed in Fig. 4, it is highly likely that c is underestimated because samples with high dose exposure are excluded. The authors of this paper analyzed the logarithm of exposure in other papers . It is necessary to explain why this paper did not do so. For the purpose
of radiological protection, the large variation of the individual doses is important, and it is inappropriate just to use the median or the average. Furthermore, c should depend on the age and lifestyles of participants, but the authors did not take that into account. Moreover, although they state “[T]hese results show that coarse-grained airborne data can be a useful
estimator for predicting the individual doses of residents living in contaminated areas” in Section 4, they do not give any information that shows the goodness-of-fit. We note that, while one of us (S. K.) has written a comment  concerning the subsequent paper , this Letter addresses separate issues on a different paper .
We thank Ms. Akemi Shima for providing us with the public documents obtained through her Freedom of Information requests.
Some of the issues pointed out in this Letter were discussed in Refs. [11, 12, 13], in the Japanese magazine KAGAKU. This Letter is composed as an original article in English, with a permission of the publisher of KAGAKU (Iwanami Shoten, Publishers). We also thank the KAGAKU Editorial Office for opportunities to discuss this work.