GIS, Multivariate Statistics Analysis and Health Risk Assessment of Water Supply Quality for Human Use in Central Mexico

Round 1

Reviewer 1 Report

I have evaluated the manuscript by Valentín Flores-Payán and co-authors. The authors reported the evaluation of water quality and risks using statistical and various other models such as risk assessment and GIS. 

1. I find it difficult to understand the main significance of the work. The authors should review and cite similar studies (e.g. https://doi.org/10.2166/wpt.2020.116), and then state the significance of the present report.
2. Line 68: what is "null treatment"? Authors should consider editing their report for grammatical accuracy. 
3. Line 96: delete "to"
4. Line 106 & Line 114 (Table 1): m.a.s.l. should be in capital letters. 
5. The equation captions/numbering are too close to the equations themselves. 
6. Table 5: What kind of standards are the values being compared to? The authors stated citations "[17,31,32]". The name of the standard reference should be provided in the Table. For example: WHO or USEPA, or UNEP, or EU, etc.
7. Line 327-336: Why is the explanation of Ewi calculation done in the discussion section. I recommend this to be done in the method section.
8. There is no figure caption for Figure S1 in the supplementary file. There is no x-axis label too for the graphs. Please check and correct. 

Author Response

Responses to the comments from the Editors and Reviewers

We wish to express our appreciation to the Editor and Reviewers for their insightful comments, which have helped us significantly to improve our manuscript. According to the suggestions, we have thoroughly revised our manuscript, and its final version is enclosed.

REVIEWER 1

First of all, we thank Reviewer 1 for the efforts in carefully reviewing our manuscript and the constructive comments. We have been able to incorporate changes to reflect most of the suggestions provided by the reviewers. We have highlighted the changes within the manuscript.

Comment 1: I find it difficult to understand the main significance of the work. The authors should review and cite similar studies (e.g. https://doi.org/10.2166/wpt.2020.116), and then state the significance of the present report.

Response: Thank you for raising this point. To address this concern, we have rewritten the paragraphs in line-121-124.  

 

Comment 2: Line 68: what is "null treatment"? Authors should consider editing their report for grammatical accuracy.

Response: The sentence was rewritten. Line 64

 

Comment 3: Line 96: delete "to"

Response: This paragraph was rewritten. Line 115

 

Comment 4: Line 106 & Line 114 (Table 1): m.a.s.l. should be in capital letters.

Response: The abbreviation was changed to capital letters. Line 129. Table S1.

 

Comment 5: The equation captions/numbering are too close to the equations themselves.

Response: Thanks for the observation. The format of equations was improved. Line: 174, 238, 240, 254, 258, 267.

 

Comment 6: Table 5: What kind of standards are the values being compared to? The authors stated citations "[17,31,32]". The name of the standard reference should be provided in the Table. For example: WHO or USEPA, or UNEP, or EU, etc.

Response: The information was added in Table 3 as WHO recommendations and the Mexican regulation NOM-041 and NOM-127. This information also was integrated in Figure 2.

 

Comment 7: Line 327-336: Why is the explanation of Ewi calculation done in the discussion section. I recommend this to be done in the method section.

Response: Thanks for the observation. The equation and its description were moved to section 2.4. Line 172-177.

 

Comment 8: There is no figure caption for Figure S1 in the supplementary file. There is no x-axis label too for the graphs. Please check and correct.

Response: The figure caption for Figure S1 was added and the figures corrected.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear authors, 

I have gone through the paper and found that author did a good work where spatial assessments of water supply quality from wells, springs, and surface bodies, were performed during the dry and rainy seasons in six municipalities in the eastern regions of Michoacán. Paper is written well by taking care of novelties, but still need some corrections before suitable for publication. Kindly find the below comments:-

1) State of the art is missing in the introduction section, kindly revised the introduction section. Authors need to focus on the key aspect of study rather then generalized. 

2) Why only NSF-WQI has been used for this study why not other, kindly write 2-3 line about the advantage of using this WQI over other WQI in introduction.

3) References [7-10] cited in the text is not very much relevant suggested to replace with recent one (Int. J. Env. Res. Public Health 17(7), 2179; https://doi.org/10.1016/j.chemosphere.2020.128855; https://doi.org/10.1016/j.chemosphere.2021.129996; https://doi.org/10.1002/ldr.3984)

4) why only two period (dry and winter) were selected for this study why not four seasons (dry, winter, monsoon, post-monsoon), is there any logic behind this ?

5) Table 1 and 2 need to be shift in supplementary sections

6) Equations 1, 2, 3, 4, 5.......need to be written like (Eq. 1), (Eq. 2).....

7) kindly remove 'by sites from the heading "3.6. Hierarchical Cluster Analysis (HCA) by sites"

8) Resolution of figure 3 need to be increase 

9) kindly write implementation of this study to regional scale and uncertainty and limitation of the study  

 

 

Author Response

Responses to the comments from the Editors and Reviewers

We wish to express our appreciation to the Editor and Reviewers for their insightful comments, which have helped us significantly to improve our manuscript. According to the suggestions, we have thoroughly revised our manuscript, and its final version is enclosed.

REVIEWER 2

First of all, we thank Reviewer 2 for the efforts in carefully reviewing our manuscript and the constructive comments. We have been able to incorporate changes to reflect most of the suggestions provided by the reviewers. We have highlighted the changes within the manuscript.

Comment 1: State of the art is missing in the introduction section, kindly revised the introduction section. Authors need to focus on the key aspect of study rather then generalized. 

Response: Thank you for raising this point. To address this concern, we have rewritten the paragraphs in line 82-107.

 

Comment 2: Why only NSF-WQI has been used for this study why not other, kindly write 2-3 line about the advantage of using this WQI over other WQI in introduction.

Response: The information was added in the introduction section. Line 87-93

 

Comment 3: References [7-10] cited in the text is not very much relevant suggested to replace with recent one (Int. J. Env. Res. Public Health 17(7), 2179; https://doi.org/10.1016/j.chemosphere.2020.128855; https://doi.org/10.1016/j.chemosphere.2021.129996; https://doi.org/10.1002/ldr.3984) Response: Thanks for the suggestion, the references were replaced in line 80.

 

Comment 4: why only two period (dry and winter) were selected for this study why not four seasons (dry, winter, monsoon, post-monsoon), is there any logic behind this?

Response: In Mexico, monsoon circulations only affect the northwest of the country (at states such Sonora, Chihuahua, Sinaloa and Durango-https://www.gob.mx/conagua/prensa/inicio-el-monzon-de-norteamerica-en-el-noroeste-de-mexico-), our study area is in the west, so it is not affected by this phenomenon.

The rainy season was selected to study the effect of hurricanes and tropical storms, equivalent to the impact of the rains caused by the monsoons.

The sampling was designed to investigate the effect of rain runoff on water quality for the study populations. In contrast, samples were taken during the dry season covering the annual period.

 

Comment 5: Table 1 and 2 need to be shift in supplementary sections

Response: Tables 1 and 2 were shifted to supplementary material. In addition, the headings, and the mentions of the other tables in the main text have been updated.

 

Comment 6: Equations 1, 2, 3, 4, 5.......need to be written like (Eq. 1), (Eq. 2).....

Response: The requested changes were made.

 

Comment 7: kindly remove 'by sites from the heading "3.6. Hierarchical Cluster Analysis (HCA) by sites".

Response: The phrase “by sites” was removed. Line: 478.

 

Comment 8: Resolution of figure 3 need to be increase 

Response: The figures changed their resolution to 600 dpi and were rearranged to obtain a larger image.

 

Comment 9: kindly write implementation of this study to regional scale and uncertainty and limitation of the study  

Response: This information was added on line 649-657.

 

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

1. The conclusion is a bit too long.
2. Line 34. Poor grammatical structure. The manuscript still requires formatting and professional English check.

Author Response

Thank you for insightful comments. We appreciate the time and effort you have dedicated to providing insightful feedback on ways to strengthen our paper. We have incorporated changes that reflect the detailed suggestions you have graciously provided. We also hope that our edits and the responses we provide below satisfactorily address all the issues and concerns you and the reviewers have noted.

Comment 1: The conclusion is a bit too long.

Response: According to reviewer’s advice, we shortened the Conclusions as follows (lines 687-711):

“Most parameters for water quality for human consumption were evaluated within limits established by international and national regulations. In some cases, they were outside those limits, such as low pH levels, turbidity, color, Fe, Al, Mn, and arsenic. ZIN, HID, and SPJ stood out for having more sites and parameters with levels outside limits established, mainly of arsenic. The calculated WQI suggests that mainly in the dry season and for each municipality, the water had a classification of "excellent water" and "good water quality,"; and only in the rainy season, the WQI of SPJ and IRI showed "poor water quality."

The PCA and HCA suggested that pollution of geologic and geothermal origin (the type of rock and interactions rock-groundwater) contributes to increasing the levels of most of the parameters analyzed in this study. In addition, the rainy is a seasonal factor that elevates concentrations of some chemical substances and influences the increase in several parameters due possibly to processes such as lixiviation for a larger amount of water from pluvial precipitations.

The GIS led to the prediction and continuous characterization of the concentrations of each study variable

For three target groups, the non-cancer risk level exceeded the recommended criteria in the rainy season, suggesting that the presence of metals represents a threat to the health of adults, children, and infants. The carcinogenic risk of water consumption based on ingestion exposure is high; therefore, residents in this study area may be at increased health risk, and authorities should pay close attention to this area. Furthermore, based on exposure assessments, children may be at increased risk for carcinogens and non-carcinogens through ingestion primarily of As. The information generated by the present work is a starting point for a better understanding of possible relationships between the water supply quality for human consumption and human health effects at the study regions. Such understanding could be attained when results like those presented here are matched to those derived from epidemiologic studies about the number of disease cases in different sectors of the human populations of Cuitzeo and the eastern Michoacán regions.”

Comment 2: Line 34. Poor grammatical structure. The manuscript still requires formatting and professional English check.

Response: Thank you for raising this point. Line 34, 50, 62, and 65 were rewritten. The entire manuscript was edited for English, grammar, punctuation, spelling, and general style.

Reviewer 2 Report

Thanks for your fruitful revision and all the best for upcoming research work

Author Response

Thank you for your wishes. We appreciate the time and effort you have put into providing valuable feedback on strengthening our document.