Assessment of Indoor Radon Gas Concentration in Latvian Households

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

Please find comments in the message attachment.

Regards

Comments for author File: Comments.PDF

Comments on the Quality of English Language

English language can be improved a little.

Author Response

Dear Editor and Reviewer,

Our manuscript entitled “Assessment of Indoor Radon Gas Concentration in Latvian Households” has been carefully corrected according to comments, objections, and suggestions.

Point by point answers to the Reviewer’s 1 comments:

 

Dear authors,

The paper provides an important issue of radon concentrations in Latvian dwellings conducted using RadTrack2 passive detectors. Besides the state-level investigation of radon gas concentration in households, the aim of the manuscript was to raise awareness about radon exposure nationwide, and if necessary, to take measures to reduce radon concentration in dwellings. This is of special interest for understanding the potential radon risk for householders.

However, the main question is: Why do the authors present the results eight years later (measurements are conducted in 2016 – if I am right)? What is the reason? Has the data been published somewhere before by the authorities or in some other way?

 

Thank you for your inquiry. Despite the project being conducted in 2016, there were delays in obtaining data from the relevant authorities for scientific analysis and, subsequently, it took time to process the results. We appreciate your feedback, and it may indicate issues with institutional collaboration. All project findings are publicly available and compiled online https://data.gov.lv/dati/lv/dataset/radona-gazes-limena-novertejums-latvija/resource/480e75c1-e3f8-49a8-bbe8-30842ec93e78 and are available in Latvian only, but until now, there hasn't been a detailed  comparison of the data presented in our paper, making it unique.

Additionally, you can check one of the most significant EU publications on the radiological situation in Europe has been the European Atlas of Radioactivity, recently, which also includes an analysis of indoor radon concentrations in households, mentioning Latvia as well. https://op.europa.eu/en/publication-detail/-/publication/a8c08fd3-56b6-11ea-aece-01aa75ed71a1/language-en  

 

General comments

The structure of the paper is good and follows the journal requirements.

The paper has value for the scientific community; it is generally well written, but should be improved. The Introduction section should be concise, accurately stated,consistently organized, with the aim of the manuscript clearly emphasized. It looks a little out of order/scope. Section Results is well written; it encompasses all factors that affect radon concentration in dwellings. However, the beginning of the section sounds like an Introduction. The same should be applied for Discussion section. Suggestions will be given below.

Some corrections of English language are needed.

 

Authors appreciate your positive comments on the structure of the paper and its value for the scientific community. The Introduction section was modified according to all reviewer's comments. All concerns regarding the scope and order of the Results and Discussion sections have been addressed. Additionally, the English language was kindly proof-edited by MDPI (please see the certificate copied below). Your suggestions have been carefully considered and implemented.

 

Particular comments and Suggestions for Authors

Lines 48-49: “Radon is a noble gas with radioactive characteristics, and under normal conditions is odorless, colorless, and tasteless.” Radon is a noble gas with radioactive characteristics, in all conditions… so it is not necessary to state this.

 

The “under normal conditions” meant the normal temperature and pressure (The NIST temperature is 20 °C (293.15 K, 68 °F) and the absolute pressure is 1 atm (14.696 psi, 101.325 kPa).

Radon is a colourless gas, 7.5 times heavier than air and more than 100 times heavier than hydrogen. The gas liquefies at −61.8 °C (−79.2 °F) and freezes at −71 °C (−96 °F). On further cooling, solid radon glows with a soft yellow light that becomes orange-red at the temperature of liquid air (−195 °C [−319 °F]). Britannica, The Editors of Encyclopaedia. "radon". Encyclopedia Britannica, 11 Apr. 2024, https://www.britannica.com/science/radon  [Accessed 19 April 2024].

 

Thank you for your feedback. We have revised the sentence to improve clarity: “Radon is a colourless and odourless, chemically inert radioactive gas” (Lines 49-50).

 

Lines 50-51: “Among the natural isotopes of radon, radon-222 is the most stable one with a half-life of approximately 3.8 days [4].” This term is inadequate. Radon is unstable. Please correct the sentence into''... , radon-222 has the longest half-life of approximately 3.8 days.''

 

We appreciate your clarification regarding the terminology. The sentence have revised as you suggested: “radon-222 has the longest half-life of approximately 3.8 days.” (Lines 51-52).

 

Lines 53-55: “Free radon gas is able to reach deepest areas of lungs irradiating them, but in dusty environments the behavior of radon would depend on particulate matter size on it was attached.” Radon is a gas, it cannot be attached to dust particles in the air, but its progeny can. So, correct this mistake.

 

Free radon gas is able to reach deepest areas of lungs irradiating them. In dusty environments, there is a mixture of radon gas, its progeny, and dust. And, the level of airways irradiated more depends on particulate matter size inhaled. We value your attention to detail. The text was revised and corrected (please see Line 54-57).

 

Line 60: Use the correct half-life of radon (3.8 days), as previously written, and check the other half-lives. State the equivalence between post-radon chains present in Figure 1 using the left–right double arrow.

 

We have ensured the correct half-life of radon (3.8 days) and verified the accuracy of the other half-lives mentioned in Figure 1 (please see below), as well as used the left–right double arrow to make the Figure clear. Your input helps improve the accuracy of our paper, and we value your attention to detail.

 

Lines 81-83: Why implement moderation measures if radon levels are low? Clarify.

 

We appreciate your question. Even if radon levels are initially low, implementing moderation measures is crucial for several reasons. Radon levels can fluctuate over time, so continuous monitoring and precautionary measures are essential. Additionally, even low levels of radon exposure can pose health risks over prolonged periods and proactive mitigation measures can prevent potential future increases in radon levels as well as ensure long-term indoor air quality and inhabitants’ safety. Text was improved (see Lines 92-95).

 

Lines 99-104: This sentence is too long, please reorder or split it.

 

Thank you for your suggestion. We have splited the text as follows: “Practical strategies, including radon gas concentration testing and raising awareness among inhabitants and policymakers, play a key role. Consequently, implementing sealing procedures by removing cracks and gaps in the foundation and floors, as well as ensuring adequate air ventilation, whether through natural means such as opening windows or using mechanical systems, helps disperse radon gas, ultimately minimizing its accumulation.”

 

Line 136: The authors should indicate in which season the detectors were exposed, or time period.

 

Thank you for your suggestion. The information have been included in the manuscript about the time period during which the detectors were exposed. The measurements were conducted during the period of  January 2016 –December 2016. (Lines 143-144).

 

Line 175-178: This sentence should be deleted or removed in the last paragraph of the Introduction. This is the aim of study.

 

Thank you for your feedback. The authors understand your perspective, however, we believe it is important to orient the reader and provide a clear understanding of the study's design. (Lines 194-197).

 

Lines 244-253: Please add some references to substantiate the assertions, and improved the discussion. A suggestion for the authors:

Radon levels and indoor air quality after application of thermal retrofit measures - a case study.Air Quality, Atmosphere & Health, 2023, 16, 363–373. https://doi.org/10.1007/s11869-

022-01278-w

 

Thank you for the opportunity to provide recommendations on the latest literature and incorporate it into our article. The study highlights the importance of considering floor type alongside insulation measures. The findings underscore the need for efficient ventilation systems to maintain healthy indoor environments and minimize occupational radon exposure, emphasizing the practical implications for building renovations and occupant safety. Some more references were added to improve the Discussion section. The updated references can enhance the credibility of the paper and provide additional support for research findings.

 

Lines 287-309: These two paragraphs completely repeat the Introduction section. This should be deleted from here.

 

Thank you for your feedback. The authors acknowledge your concern regarding the repetition of content in the Introduction and Discussion sections. The content had been removed. (Lines 313-327)

 

Lines 310-314: These sentences sound like ‘Conclusion’, and can be moved there.

 

Thank you for your suggestion. While we acknowledge that these sentences share similarities with those typically found in a conclusion, we believe they also contribute to the discussion by providing key insights. The text was moved closer to the end of the Discussion section. (Line 406-410).

 

Waiting for your reply.

Good luck

 

The Authors are grateful for your time and valuable suggestions. All of your constructive suggestions have been carefully reviewed. We believe that the necessary corrections have been made based on your feedback. Please take a moment to review the revised text.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have conducted a significant survey on radon concentrations in Latvian households. However, substantial improvements are needed for the manuscript to be considered for acceptance. Here are my specific comments:

1) Line45-47: One percent more time spent at home does not seem to be a large increase, which means that the increase in the health effects of radon on people does not seem to be large. If I am wrong, please explain in detail.

2) Line74-77: The current paragraph is notably brief and lacks cohesion with surrounding text. It could be merged with the introductory paragraph to more effectively highlight the dangers of radon gas.

3) Line115-126: The author's description of the survey process is not clear. Was the survey conducted in 2016? If yes, it has been nine years, is there a timeliness issue with the data? Because the architectural form and other factors may change with the change of economic level and other factors.

4) Line287-300: The impact of radon radiation on human health has already been emphasized earlier in the text. I recommend deleting this paragraph or integrating its contents into an earlier section to avoid redundancy.

5) Line339-350: Similar to the previous point. This paragraph, which emphasizes the effects of radon on vulnerable groups, also seems to have little significance and should not be included in the discussion section.

6) Discussion Section: The authors should enhance the discussion by exploring how factors like building age, type, presence of a cellar, and ventilation influence radon gas concentrations.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

Dear Editor and Reviewer,

Our manuscript entitled “Assessment of Indoor Radon Gas Concentration in Latvian Households” has been carefully corrected according to comments, objections, and suggestions.

Point by point answers to the Reviewer’s 2 comments:

The authors have conducted a significant survey on radon concentrations in Latvian households. However, substantial improvements are needed for the manuscript to be considered for acceptance. Here are my specific comments:

• Line 45-47: One percent more time spent at home does not seem to be a large increase, which means that the increase in the health effects of radon on people does not seem to be large. If I am wrong, please explain in detail.

Thank you for your observation. While it may seem that a 1% increase in time spent at home would not result in significant health effects from radon exposure, it's essential to consider the tendency and the cumulative impact over time and the potential interactions with other factors. Your attention to detail have been appreciated.

• Line 74-77: The current paragraph is notably brief and lacks cohesion with surrounding text. It could be merged with the introductory paragraph to more effectively highlight the dangers of radon gas.

The paragraph was merged with the previous one to conclude it and emphasize the importance of the topic. (Line 78-81).

• Line115-126: The author's description of the survey process is not clear. Was the survey conducted in 2016? If yes, it has been nine years, is there a timeliness issue with the data? Because the architectural form and other factors may change with the change of economic level and other factors.

While the survey was indeed conducted in 2016, there were delays in obtaining data from the relevant authorities for scientific analysis and, subsequently it took time to process the results.

In the last decade, the architectural forms, building methods and other factors havn’t been changed much, and geolocical conditions or economic level as well. The obtained data are still actual for protection inhabitants and their health. Thank you for your inquiry. 

• Line287-300: The impact of radon radiation on human health has already been emphasized earlier in the text. I recommend deleting this paragraph or integrating its contents into an earlier section to avoid redundancy.

Thank you for your feedback. The authors acknowledge your concern regarding the repetition of content in the Introduction and Discussion sections. The content had been removed. (Lines 313-327)

• Line339-350: Similar to the previous point. This paragraph, which emphasizes the effects of radon on vulnerable groups, also seems to have little significance and should not be included in the discussion section.

Thank you for your suggestion. However, the authors respectfully disagree with the notion that the paragraph emphasizing the effects of radon on vulnerable groups lacks significance. These insights are crucial for understanding the broader implications of radon exposure and its potential impact on public health, particularly for vulnerable population. Therefore, we believe it is important to retain this information in the discussion section. The text was slighty corrected. (Lines 392-406)

• Discussion Section: The authors should enhance the discussion by exploring how factors like building age, type, presence of a cellar, and ventilation influence radon gas concentrations.

Thank you for your feedback. The Discussion section was slightly improved and supplied with the references according to factors mentioned (please see the text).

The Authors are grateful for your time and valuable suggestions. All of your constructive suggestions have been carefully reviewed. We believe that the necessary corrections have been made based on your feedback. Please take a moment to review the revised text.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This work is an interesting piece of work. In addition, some important points should be explain in more detail before formal acceptance. The specific questions for authors and comments are followings:

Line 37-38: It isn't clear. Please clarify what you mean by "other environments."

Line 98: Please consolidate the citations ([16], [18], [19], [20]) into a single pair of brackets.

Materials and Methods: Clarify the logical basis behind the selection of the number of measurements in each municipality as shown in Table S1. Are the measurements proportional to the area of each municipality or ..

? Please provide an explanation or cite the relevant instructions from RSC SES. Consider including a brief geographic description of Latvian municipalities to enhance the discussion and facilitate comparisons with other studies.

Section 2.3: Include the detection limits of radtrack2 devices and discuss in the Discussion sections why uncertainty is high in certain measurements.

Results: In Figure 2, explain why you are using the median radon concentration by municipalities for the map. Given the varying sizes of municipalities, consider discussing whether interpolation methods could provide a more accurate representation. Provide a detailed explanation of your choice.
Consider adding ANOVA analysis (f-value) in Table 1 to assess differences between buildings, types of household, and conditions.

Discussion: Ensure a clear connection between the Results and Discussion sections. Refine the Discussion section to avoid it resembling an introduction (too general Line 287-314). Provide specific discussion information to enhance readability and coherence for the readers. Authors should also include comparisons with other similar studies that use same parameters.

Author Response

Dear Editor and Reviewer,

Our manuscript entitled “Assessment of Indoor Radon Gas Concentration in Latvian Households” has been carefully corrected according to comments, objections, and suggestions.

Point by point answers to the Reviewer’s 2 comments:

The authors have conducted a significant survey on radon concentrations in Latvian households. However, substantial improvements are needed for the manuscript to be considered for acceptance. Here are my specific comments:

• Line 45-47: One percent more time spent at home does not seem to be a large increase, which means that the increase in the health effects of radon on people does not seem to be large. If I am wrong, please explain in detail.

Thank you for your observation. While it may seem that a 1% increase in time spent at home would not result in significant health effects from radon exposure, it's essential to consider the tendency and the cumulative impact over time and the potential interactions with other factors. Your attention to detail have been appreciated.

• Line 74-77: The current paragraph is notably brief and lacks cohesion with surrounding text. It could be merged with the introductory paragraph to more effectively highlight the dangers of radon gas.

The paragraph was merged with the previous one to conclude it and emphasize the importance of the topic. (Line 78-81).

• Line115-126: The author's description of the survey process is not clear. Was the survey conducted in 2016? If yes, it has been nine years, is there a timeliness issue with the data? Because the architectural form and other factors may change with the change of economic level and other factors.

While the survey was indeed conducted in 2016, there were delays in obtaining data from the relevant authorities for scientific analysis and, subsequently it took time to process the results.

In the last decade, the architectural forms, building methods and other factors havn’t been changed much, and geolocical conditions or economic level as well. The obtained data are still actual for protection inhabitants and their health. Thank you for your inquiry. 

• Line287-300: The impact of radon radiation on human health has already been emphasized earlier in the text. I recommend deleting this paragraph or integrating its contents into an earlier section to avoid redundancy.

Thank you for your feedback. The authors acknowledge your concern regarding the repetition of content in the Introduction and Discussion sections. The content had been removed. (Lines 313-327)

• Line339-350: Similar to the previous point. This paragraph, which emphasizes the effects of radon on vulnerable groups, also seems to have little significance and should not be included in the discussion section.

Thank you for your suggestion. However, the authors respectfully disagree with the notion that the paragraph emphasizing the effects of radon on vulnerable groups lacks significance. These insights are crucial for understanding the broader implications of radon exposure and its potential impact on public health, particularly for vulnerable population. Therefore, we believe it is important to retain this information in the discussion section. The text was slighty corrected. (Lines 392-406)

• Discussion Section: The authors should enhance the discussion by exploring how factors like building age, type, presence of a cellar, and ventilation influence radon gas concentrations.

Thank you for your feedback. The Discussion section was slightly improved and supplied with the references according to factors mentioned (please see the text).

The Authors are grateful for your time and valuable suggestions. All of your constructive suggestions have been carefully reviewed. We believe that the necessary corrections have been made based on your feedback. Please take a moment to review the revised text.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

1.      In the introduction, the author described too much about the harm of radon gas to the human body. Please simplify it.

 

2.      In the introduction, the authors should try to indicate what predecessors have done in similar research work to highlight the guidance for this paper.

 

3.      The current study appears to have merely conducted a statistical analysis of indoor radon concentrations in Latvian households, lacking evident innovation. The authors are kindly requested to provide an overview of the novel contributions of this research.

 

4.      This study used detector measurement and questionnaire surveys to evaluate the indoor radon concentration. Please describe the contents of the questionnaire appropriately.

 

5.      In section 2.3 of the manuscript, the authors are advised to insert a picture of the RadTrack2 passive detector

 

6.      The data processing and statistical methods in Section 2.4 of the manuscript should be described in greater detail.

 

7.      Does the survey sample size support this study?

 

8.      Figure 2 lists the distribution of median radon concentration levels by the municipalities of Latvia, and it is recommended to add a description of the distribution characteristics of median radon concentration.

 

9.      The author listed and analyzed the characteristics of various factors affecting radon levels. Can you try to analyze the weight of each factor's influence, i.e. the degree of influence?

 

10.   The discussion in section 4 of the manuscript lacks logic and appears cluttered.

 

11.   It is suggested that the authors enumerate measures for reducing radon concentrations and preventing the impacts of radon exposure in the manuscript.

 

12.   In the discussion section, the authors claim to have provided a direct statistical method for assessing uncertainty. I have some concerns regarding the application and advantages of this method. Could the authors please provide a detailed explanation?

Comments on the Quality of English Language

English has more long sentences, which generally need to be broken down into several short sentences. The quality of English is basically up to the requirement.

Author Response

Dear Reviewer,

all of your constructive suggestions have been carefully reviewed. We believe that the necessary corrections have been made based on your feedback. Please take a moment to review the point by point responses (please see the attachment).

Best regards.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

I really appreciate the author's response. However, I am sorry to say that I do not fully understand the order of their response. The authors mentioned that they would respond point by point; however, there are some important points that seem to be missing. I will enumerate each comment, and I hope the author could clarify these points and provide explanations.

COMMENT 1: Line 37-38: It isn't clear. Please clarify what you mean by "other environments."

COMMENT 2: Line 98: Please consolidate the citations ([16], [18], [19], [20]) into a single pair of brackets.

COMMENT 3: Materials and Methods: Clarify the logical basis behind the selection of the number of measurements in each municipality as shown in Table S1. Are the measurements proportional to the area of each municipality or ..

? Please provide an explanation or cite the relevant instructions from RSC SES. Consider including a brief geographic description of Latvian municipalities to enhance the discussion and facilitate comparisons with other studies.

COMMENT 4: Section 2.3: Include the detection limits of radtrack2 devices and discuss in the Discussion sections why uncertainty is high in certain measurements.

COMMENT 5: Results: In Figure 2, explain why you are using the median radon concentration by municipalities for the map. Given the varying sizes of municipalities, consider discussing whether interpolation methods could provide a more accurate representation. Provide a detailed explanation of your choice.
Consider adding ANOVA analysis (f-value) in Table 1 to assess differences between buildings, types of household, and conditions.

COMMENT 6: Discussion: Ensure a clear connection between the Results and Discussion sections. Refine the Discussion section to avoid it resembling an introduction (too general Line 287-314). Provide specific discussion information to enhance readability and coherence for the readers. Authors should also include comparisons with other similar studies that use same parameters.

Author Response

Dear Reviewer,

It seems that some kind of miscommunication happened regarding the attachment of the point-by-point responses. In our revised submission of the Round 1, we have ensured that the responses were included in a separate file for ease of evaluation answering point by point to every comment. We appreciate the reviewer's suggestions and understanding and hope that now our corrections and answers will be clearly seen (please see the attachment).

Best regards.

Author Response File: Author Response.pdf