Radon Exposure to the General Population of the Fernald Community Cohort

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript submitted for review is highly interesting due to its specificity and uniqueness. The reading experience is both engaging and complex, particularly for readers familiar with residential radon monitoring studies. While my area of expertise does not extend to modeling the distribution of outdoor air pollutants—such as radon in this case—I do not feel qualified to comment on the modeling methodology itself.

However, from my perspective as an experimentalist in the field of radon, I believe that several additional clarifications could further strengthen the manuscript.

For example, in lines 76–78, it is mentioned that the estimated amount of radon released between 1952 and 1988 is 160,000 Ci. Could the authors provide more details on how this estimate was obtained? Reference [2] appears to lead to an archived page with limited accessibility ("This page is archived for historical purposes and is no longer being updated"), and as such, the original report cannot be accessed for verification.

In Table 4, given the wide range of values calculated for mean and maximum exposure, I would suggest reporting the values with no more than two decimal places to enhance clarity and readability.

Considering the historical estimates of radon emissions from silos 1 and 2, was there any past long-term or medium-term residential radon monitoring study conducted in the area? If so, comparing the modeled data in this manuscript with historical measured data could provide valuable validation and context.

On line 426, a value of 1.44 Sv is presented as the highest median radon-related dose. Since the sievert (Sv) refers to effective dose, could the authors clarify whether this refers to the equivalent dose resulting from exposure to the highest median radon concentration? The authors are commendably transparent in stating the limitations of this estimate. As a complement, I believe it would be beneficial to report the average indoor radon concentration in Ohio. This would help readers better understand the implications of radon emissions from silos in comparison to typical indoor radon exposure resulting from soil infiltration in a standard Ohio home.

Furthermore, it would add value if the authors could include any available data on lung cancer incidence in the affected area, compared to statewide or national statistics. Lastly, unless this has already been addressed and I may have overlooked it, it is important to specify the assumed time a person is expected to spend indoors versus outdoors, and whether radon infiltration from soil was accounted for in the estimation of annual average exposure.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Reichard et al. present results describing radon exposures to the general population of the Fernald community based on air dispersion modeling and residential data. Overall, the manuscript is well-presented, the science is high-quality, and I was impressed by the level of detail taken by these authors to accurately model exposures. A few changes are needed, however, before I can recommend this manuscript for publication.

 

Major comments:

-The air dispersion model does not appear to take into account that the half-life of 222Rn is only 3.8 days. Depending on the atmospheric residence time and/or time it takes for Radon to travel from the site to the surrounding community, a fraction of the Radon could have already decayed to 218Po. Please either include an exponential decay equation to address this effect or discuss in the text why a correction for radioactive decay could be ignored based on the travel time of the 222Rn.

 

Minor comments:

-Line 40: please define the word raffinate.

-Lines 95-98: The way this sentence is phrased creates the impression that the alpha decay of the 222Rn and daughter products creates health hazards, not the effect of decay to solid phase radionuclides such as 218Po and 210Pb, which can be retained in the lungs. Radon itself can leave the lungs given that it is a gas; it is thus the daughter products that are retained and continue to decay that are a greater concern for health. Please describe the health effects of radon more carefully here.

-It would be helpful to have a schematic/diagram in the introduction of the silos. The measurements/dimensions of the silos and history are useful but it would be easier for readers to visualize with a figure.

-Figures 4 and 5. Consider removing the gray background and gridlines from these plots. These look like default python/ggplot plots and the gray background makes it hard to see the lines in Figure 4.

-Lines 246-248: It would be helpful to have some context for the reader as to what Task 6 of the Fernald Dosimetry project is. It is hard to follow the logic in this paragraph without that context.

-Line 445: change “reconstructions” to “reconstruction”

-Line 470: change “allow” to “allows”

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Good job on your paper--I appreciate the thorough and detailed responses to reviewer comments! This manuscript is now suitable for publication.

 

Please fix one minor typo in your revised text before final publication.

In the following sentence, change "spares sets" to "spare sets": "The mathematical computation of the Rn diffusion function is complex because it is based on two relatively spares sets
of air monitoring data collected in the 1980s, as well as average annualized radon emission rates for both unconstrained (pre-1980) and constrained (post1980) daytime and nighttime silo radon release, and Pasquill-Gifford atmospheric stability frequencies." 

Author Response

We thank the reviewer for calling our attention to the typographical error. We have made corrections and are resubmitting the manuscript. We are happy to address any additional comments or questions.

Again, we would like to express our gratitude to the reviewer for the time they spent reviewing this manuscript, for their attention to detail and their insightful comments. We strongly feel that the reviewers’ comments made us think more deeply on some of the issues we discuss in this manuscript and as a result they improved this work. Thank you.

- John