Investigation of Radon in Groundwater and the Corresponding Human-Health Risk Assessment in Northeastern Saudi Arabia
Round 1
Reviewer 1 Report
Dear Authors,
Investigation of radon in groundwater is of interest for determination of populaion exposure to radon by ingestion or inhallation.
However measurements are performed very locally and also investigated region is not an RPA to be of broader interest for scientific community. Thus, this paper is of very local interest.
Comments are given in the paper, however, I would also like to ask authors to pay attention in explaining methodology. One would expect to measure build up of radon concentration in time, until reaching equilibrium between 222Rn and 218Po. Why was only 2 minutes sampling time used (and when performing averaging, at least first 10-15 minutes of measurements should be excluded... i.e. first several halflives of 218Po should be omitted (until reaching equilibrium). Please explain your methodology in detais.
All other comments are in the attached document.
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer 1 Comments
First, we thank the Editor, Associate Editor, and reviewer for their valuable comments. All the comments are essential to improve the quality of our manuscript. We have included responses to their comments and revised the manuscript accordingly.
Please find the attached responses.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Overall, this is a sound study and the results are worthy of publication. Many of the resources from national and international organizations are dated and need to be updated and reviewed. Also, there are strong statements made regarding the relationship between radon exposure via the ingestion route that are not fully supported by the literature.
Author Response
Response to Reviewer 2 Comment
Overall, this is a sound study and the results are worthy of publication. Many of the resources from national and international organizations are dated and need to be updated and reviewed. Also, there are strong statements made regarding the relationship between radon exposure via the ingestion route that are not fully supported by the literature.
Response: We thank the reviewer for the positive response. We completely agree with the reviewer about the need for updated and reviewed data. According to the WHO, to date, epidemiological studies have not confirmed an association between the consumption of drinking water containing radon and an increased risk of stomach cancer. Radon dissolved in drinking water is released into indoor air. Normally, a higher radon dose is received from inhaling radon compared with ingestion, which is in accordance with the reviewer’s comment. Truly, thanks for this statement.
Author Response File: Author Response.docx
Reviewer 3 Report
see pdf-file
Comments for author File: Comments.pdf
Author Response
Response to Reviewer 3 Comments
First, we thank the Editor, Associate Editor, and reviewer for their valuable comments. All the comments are essential to improve the quality of our the manuscript. We have included responses to their comments and revised the manuscript accordingly.
Please see the attached response in details.
Author Response File: Author Response.docx
Reviewer 4 Report
The reviewed manuscript is dealing with the investigation of radon in groundwater and the corresponding human health risk assessment in the northeastern part of Saudi Arabia. Using a portable RAD7 radon detector, the radon concentration and the total effective dose for radon exposure via ingestion and inhalation of water are calculated for different age groups. In general, the manuscript is interesting. I recommend this manuscript publication after minor revision. I expressed some remarks below, believing that they can help authors to improve the final version.
1. The title does not match the content. I suggest adding the specific investigated area (Hafr Al Batin, Saudi Arabia) or the general location (northeastern Saudi Arabia).
2. Line 33; ‘‘radon can be exposed by inhalation by breathing’’ Please revise this sentence.
3. Line 49; ‘‘many countries’’ replace with many researchers.
4. Line 69; ‘‘age limits’’ replace with age groups.
5. Line 74; It will be better to add subtitles in this section such as The Study Area, Sampling, Radon Measurement, and Dose Assessment.
6. Line 75; ‘‘Thybia’’ the used village name does not match the name displayed in Figure 1.
7. Line 76; ‘‘the Kingdom’’ replace with Saudi Arabia.
8. Figure 1; This figure should be improved by adding a coordinate (Long. and Lat.). It is incorrect for writing the names in Arabic.
9. Line 89; ‘‘Vincent and Alsharhan et al.’’ replace with Vincent [26] and Alsharhan et al. [27].
10. Lines 89:93; What about the secondary origins?
11. Lines 98:99; ‘‘granite and metamorphic rocks’’ Are these rock types encountered in the study area's groundwater aquifers?
12. Figure 4; Radon concentration in the air Bq/L or Bq/m3?
13. Line 201; ‘‘the national limit’’ What about this national limit?
14. Lines 202:205; Are there any previous studies on radionuclides (uranium/thorium) levels in these sedimentary rocks? Please support your discussion.
15. Lines 206:210; ‘‘Many national and international organizations’’ all the mentioned organizations can be considered as international.
16. Lines 229:230; ‘‘The geological nature of the sampling area, soil nature, and environment can differ in the radon concentration’’ Please support this sentence with literature.
17. Line 250; ‘‘radon level’’ Please revise.
18. Conclusions; Can you add any recommendations for further studies?
Author Response
Response to Reviewer 4 Comments
First, we thank the Editor, Associate Editor, and reviewer for their valuable comments. All the comments are essential to improve the quality of our manuscript. Therefore, we have included responses to their words and revised the manuscript accordingly.
Please find the attached files for details responses.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Dear Authors,
Thank you for thoroughly going through the comments and correcting them. I do not have further comments.
Sincerely,
