Urban Stormwater Quality in Arequipa, Southern Peru: An Initial Assessment

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Attached in the file

Comments for author File: Comments.pdf

Author Response

The authors deeply thank Reviewer 1 for taking the time and effort to read and improve our manuscript. We have addressed all the reviewer’s requests and the responses are below. We are confident that the reviewer will find this improved version good enough for publication.

 

1. Discussing the implications of the high concentrations of B, Cu, Fe, Mn, and Zn in urban stormwater for downstream ecosystems and human health. Response: The authors thank the reviewer for the suggestion. Though has been already addressed in the manuscript (paragraphs staring at lines 242 and 269, original draft), we added new references when appropriate.

 

2. Exploring the potential sources of B, Cu, Fe, Mn, and Zn in urban stormwater, and whether they are related to vehicle-related contaminants. Response: The authors thank the reviewer for the suggestion. Even though this has been already addressed in paragraphs starting at lines 269, 288, and 296 in the original manuscript, we have incorporated additional references and text.

 

3. Recommending further investigations into the effects of urban stormwater on downstream ecosystems in Peru, and the need for new regulations and preventive/treatment practices to minimize pollution and ensure healthy water for irrigation. Response: The authors thank the reviewer for the suggestion. Even though this was already addressed in the manuscript (Paragraphs staring at lines 345 and 366), we have incorporated additional references.

 

The author could incorporate these suggestions into the paper:

 

Introduction

 

- Provide background information on urban stormwater pollution in Arequipa, Peru, including the sources of pollution and the current state of pollution. Response: The authors thank the reviewer for this suggestion. However, as stated in the Introduction, no information is available on urban stormwater pollution in Arequipa, neither in Peru, making this study pioneer in this important topic. Moreover, we have incorporated additional text so that the reader better understands this important fact.

 

- Discuss the potential health risks associated with exposure to B, Cu, Fe, Mn, and Zn, including their carcinogenic and toxic effects. Response: The authors thank the reviewer for suggesting the discussion of the health effects of metals found above MPLs on human health. However, this was already addressed in the manuscript, as previously mentioned but we have incorporated additional references.

 

- Highlight the need for further research on the health impacts of urban stormwater pollution in Arequipa, given the high concentrations of these metals in stormwater samples. Response: The authors thank the reviewer for this suggestion. Even though this was already addressed in the manuscript, as previously mentioned, we have incorporated additional text and references.

 

Methods

 

- Describe the sampling methods and analytical techniques used to measure B, Cu, Fe, Mn, and Zn concentrations in urban stormwater samples. Response: The authors thank the reviewer for this suggestion. Though sampling methods were already addressed in the manuscript (paragraph starting at Line 84), the authors agree that there is a need for more details about metal analysis. A description of metal determination procedures was added.

 

- Discuss the statistical methods used to analyze the data, such as regression analysis and principal component analysis. Response: The authors thank the reviewer for this suggestion. Statistical analyses consisted of graphical interpretations and correlation matrixes, which are mentioned in the last sentence of Methods.

 

Results

 

- Present the results of the study, including the concentrations of B, Cu, Fe, Mn, and Zn in urban stormwater samples, as well as the sources of these metals and the environmental factors that influence their concentrations. Response: The authors thank the reviewer for this comment. However, concentrations of all analytes (including B, Cu, Fe, Mn, and Zn) are showing in figures and SI material. Moreover, sources of pollution for each metal and environmental factors are (and should be) addressed in the Discussion.

 

Discussion

 

- Interpret the results of the study, discussing the implications of the high concentrations of B, Cu, Fe, Mn, and Zn in urban stormwater for downstream ecosystems and human health. Response: The authors thank the reviewer for this suggestion. However, this has been already addressed in the manuscript, as previously mentioned, but we added additional references.

 

- Explore the potential sources of B, Cu, Fe, Mn, and Zn in urban stormwater, and whether they are related to vehicle-related contaminants. Response: The authors thank the reviewer for this suggestion. However, this has been already addressed in the manuscript, as previously mentioned.

 

References

 

- There are fewer numbers of new references or recent references especially related to as Urban water Quality studies. Therefore, for current study should be given a strong impact if you can cite the following reference: “Per-and polyfluoroalkyl substances in water and wastewater: A critical review of their global occurrence and distribution”. Response: The authors thank the reviewer for this suggestion. Even though the suggested reference is not related to our study because it is focused on PFAS, we have incorporated this reference as a recommendation for future investigations, as we believe PFAS is an important factor to be analyzed in urban environments.

 

Conclusion

 

- Discuss the limitations of the study and suggest areas for future research. Response: The authors thank the reviewer and agree. New text was incorporated into the conclusions.

 

- Conclude with a call to action, urging policymakers and stakeholders to take action to address urban stormwater pollution in Arequipa and protect the health of local communities and downstream ecosystems. Response: The authors thank the reviewer for the suggestion. However, this important point is already addressed in the last paragraph of the Conclusions.

 

-There are lots of commas and full stops are missing. Response: The authors thank the reviewer for noticing. Grammar was checked and corrected accordingly.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

General comment: 

In this study, Martinez and colleagues characterized the urban stormwater quality in a drainage area of Arequipa city in Peru collected during the 2022 and 2023 rainy seasons, intending to provide an initial scientific assessment about the occurrence of metal pollutants, and the need for stormwater treatment and stronger environmental regulations in the country. The results emphasized the presence of several metals, particularly at the beginning of each rainy season and during the first flush stages, that could have potential implications for aquatic ecosystems and human health. Although the study is not entirely novel, the results obtained here are interesting and offer valuable insights for future decision-making in managing aquatic ecosystems and human health risks. I recommend the authors address the few comments and suggestions mentioned below.

Minor comments:

Line 109: It should only be “referred to”; remove “for”. 

Line 112: Remove “hence”.

Line 117: Maintain a consistent pattern for naming the two rainy seasons: use either the first and second rainy seasons or the 2022 and 2023 rainy seasons throughout the manuscript. For instance, here you are mentioning the first and second rainy seasons. However, at line 131, it was changed to the 2022 rainy season. So, maintain consistency in the manuscript. 

Line 143: Change the dates from Spanish to English in the Table S2 and S3.

Line 233: Change the numbering for the Discussion section from 3 to 4 and also the subsections accordingly.

Comments on the Quality of English Language

Overall, the quality of English in the manuscript is good and acceptable but try to reduce words that do not sound scientific. For instance, words like “Climatically speaking” and “shocking” are in line 120 and 402, respectively.

Author Response

The authors deeply thank Reviewer 2 for taking the time and effort to read and improve our manuscript. We have addressed all the reviewer’s requests and the responses are below. We are confident that the reviewer will find this improved version good enough for publication.

 

Line 109: It should only be “referred to”; remove “for”. Response: We apologize for the error and thank the reviewer for noticing. The word “for” has been deleted.

 

Line 112: Remove “hence”. Response: The word “hence” has been removed, as suggested.

 

Line 117: Maintain a consistent pattern for naming the two rainy seasons: use either the first and second rainy seasons or the 2022 and 2023 rainy seasons throughout the manuscript. For instance, here you are mentioning the first and second rainy seasons. However, at line 131, it was changed to the 2022 rainy season. So, maintain consistency in the manuscript. Response: The authors thank the reviewer for the suggestion and agree. The suggestion was incorporated in the entire manuscript.

 

Line 143: Change the dates from Spanish to English in the Table S2 and S3. Response: The authors thank the reviewer for noticing. Dates were modified accordingly.

 

Line 233: Change the numbering for the Discussion section from 3 to 4 and also the subsections accordingly. Response: The authors apologize for the error and thank the reviewer for noticing. Numbers have been changed accordingly.

 

Overall, the quality of English in the manuscript is good and acceptable but try to reduce words that do not sound scientific. For instance, words like “Climatically speaking” and “shocking” are in line 120 and 402, respectively. Response: The authors thank the reviewer and agree. The entire manuscript has been reviewed to avoid non-scientific terms.

Author Response File: Author Response.pdf