Research on the Characteristics of Heavy Metal Pollution in Lake and Reservoir Sediments in China Based on Meta-Analysis
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript presents a large-scale meta-analysis of heavy metal contamination in Chinese lake sediments, incorporating over 170 papers published from 2003 to 2022. The use of Monte Carlo simulation for uncertainty assessment and the application of the Igeo, RI, and STU indices provide a multifaceted evaluation of pollution severity and ecological risks. The authors address an important environmental issue with implications for water quality management and public health. However, while the structure of the paper is overall logical and the dataset is comprehensive, several aspects require revisions.
Q-I. The phrase the severity of Cr contamination is relatively low, and 54.5% of the lakes exceed the soil Background values (mentioned in the Abstract) is contradictory. If more than half the lakes exceed the background level, the term “relatively low” needs to be quantitatively justified.
Q-II. Background values is used interchangeably with soil background values. In some places, environmental background value is also used. These should be clearly defined and used consistently throughout the text.
Q-III. While the authors correctly focus their data analysis on heavy metal contamination in Chinese lakes, the Introduction section lacks a broader geographical context that would position the research within a global framework. The current literature review relies exclusively on Chinese sources, which, although logical for the study’s core methodology, limits the perception of the topic’s international relevance. To enhance the scholarly impact of the manuscript, I recommend citing studies from other geographical regions facing similar heavy metal pollution challenges. For instance, relevant recent studies include (from different countries):
Alybaeva, R., Akhambayeva, N., Inelova, Z., Atabayeva, S., Authanova, N., & Kalmakhan, M. (2021). Features of the accumulation of heavy metals by different genotypes of spring wheat under conditions of soil contamination with copper and lead. Engineering Journal of Satbayev University, 143(1), 110–119. https://doi.org/10.51301/vest.su.2021.v143.i1.15
Rysbekov K., Yinli, B., Demeuov, S., Mukanova, G., & Zhakypbek, Y. (2021). Assessment of soil polution by нeavy metals in the area of open mining works. Engineering Journal of Satbayev University, 143(6), 14–25. https://doi.org/10.51301/vest.su.2021.i6.03
Popovych, V., Skrobala, V., Tyndyk, O., & Kaspruk, O. (2024). Hydro-ecological monitoring of heavy metal pollution of water bodies in the Western Bug River basin within the mining-industrial region. Mining of Mineral Deposits, 18(4), 139-152. https://doi.org/10.33271/mining18.04.139
Sheremeti-Kabashi, F., Kutllovci, F., Mangjolli, B., Hasani, A. (2024). Investigation of heavy metal concentrations in the Kelmend tailings landfill and ecological assessment of pollution. Mining of Mineral Deposits, 18(1), 110-118. http://mining.in.ua/2024vol18_1_12.html
Incorporating such references into the Introduction would demonstrate that the problem of heavy metal contamination is not only a localized Chinese concern but part of a broader global issue.
Q-IV. Section 3.3.2 attributes high Cd contributions in quadrants 2 and 3 to industrial wastewater and smelting without citing specific regional studies. Statements such as the intensive zones intended for mining development are located in the southern karst regions… (p. 14) require explicit references to back them up.
Q-V. In Section 2.3.1, the formula for SNWM is incomplete in the PDF file of the paper, or I do not understand the logic of it.
Q-VI. The Monte Carlo simulation methodology (Section 2.1.2) mentions the use of Crystal Ball software. However, the source of the assumed normal distribution is not justified. What tests were used to determine normality in the original datasets?
Q-VII. PCA is properly described in structure, the interpretation in Section 4.2 is too poor. Here the attributing Principal Component 3 to natural sources based on high Cr and Ni loadings lacks supporting geochemical data
Q-VIII. The phrase lakes are in a unpolluted ( p.12, p.13) contains a grammatical error. It should be lakes are unpolluted or in an unpolluted state
Q-IX. The statement the proportion of heavy metals with a greater coefficient of variation than 0.5 ranges from 18% to 43.3%. Please clarify in discussion. What does it mmean?
Q-X. Tables 4 and 5 provide quadrant-based risk/toxicity indices. On my opinion summary table or plot comparing Igeo, RI, and STU values by quadrant would enhance clarity of regional trends. It is difficult to me and potential reader to jump from page to page to evaluate data
Q-XI. Describe noveltyy of the paper in the conclusion section.
Q-XII. The paper that describe meta-analysis has made a positive impact, and with the incorporation of the suggested revisions and recommendations, may be suitable for publication in the Sustainability journal.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments and Suggestions for AuthorsDear authors, thank you for submitting your paper into sustainability journal. The following comments will help you to improve the paper:
1) Clearly state the novelty of this work: your statement should start as follows''The state of art of this work is...."
2) The keyword should be arranged in alphabetical order.
3) Some references need to be changed to latest ones
Comments on the Quality of English LanguageN/A
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
Comments and Suggestions for AuthorsThe article is devoted to the analysis of the situation with pollution of water bodies in China based on the state of bottom sediments. The article is generalizing and contains a large amount of factual material. The materials in the article are carefully selected and analyzed over vast areas of China. Cd is the main pollutant in lake sediments throughout China, followed by Cu, Zn, Pb, Ni and Cr. Unfortunately, the authors were unable to include mercury in the analysis as the most toxic element. To assess the degree of pollution, the authors used the Nokanson method, although an analysis of the enrichment factor would have been more informative. In addition, there are works that propose standards for assessing the pollution of bottom sediments. The conclusions are clear already based on the location of industries in China. I consider it possible to publish this large work, but in the future, take into account later works on bottom sediments.
Comments on the Quality of English LanguageThe article is devoted to the analysis of the situation with pollution of water bodies in China based on the state of bottom sediments. The article is generalizing and contains a large amount of factual material. The materials in the article are carefully selected and analyzed over vast areas of China. Cd is the main pollutant in lake sediments throughout China, followed by Cu, Zn, Pb, Ni and Cr. Unfortunately, the authors were unable to include mercury in the analysis as the most toxic element. To assess the degree of pollution, the authors used the Nokanson method, although an analysis of the enrichment factor would have been more informative. In addition, there are works that propose standards for assessing the pollution of bottom sediments. The conclusions are clear already based on the location of industries in China. I consider it possible to publish this large work, but in the future, take into account later works on bottom sediments.
Author Response
请参阅附件。
Author Response File: Author Response.docx
Reviewer 4 Report
Comments and Suggestions for AuthorsRearrange, rewrite your manuscript with a clear explanation
Comments for author File: 
Comments.pdf
Grammatical problems and odd language make the book hard to understand.
Highly recommended: professional English editing. Grammar and language should be improved throughout the manuscript.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsDear Authors,
I would like to express my satisfaction with the revisions made to the manuscript titled “Research on the Characteristics of Heavy Metal Pollution in Lake and Reservoir Sediments in China Based on Meta-Analysis.”
Your thoughtful incorporation of the recommended changes has significantly enhanced the overall quality of the work.
Thank you for your diligent efforts in addressing the suggestions.
Best regards,
Reviewer
Author Response
我们在此再次对编辑和审稿人对我们论文的宝贵贡献表示最深切的感谢。
Reviewer 2 Report
Comments and Suggestions for AuthorsIt is ok now and can be accepted.
Author Response
我们在此再次对编辑和审稿人对我们论文的宝贵贡献表示最深切的感谢。
Reviewer 4 Report
Comments and Suggestions for AuthorsThe phrase "the soil background values" is repeated multiple times inside the manuscript, specifically four times, in the same paragraph (lines 319 to 330) within Section 3.1.1. The authors are encouraged to vary the wording to improve readability and avoid redundancy. Consider rephrasing or using synonyms to maintain clarity while enhancing the flow of the text.
Comments on the Quality of English LanguageThe phrase "the soil background values" is repeated multiple times inside the manuscript, specifically four times, in the same paragraph (lines 319 to 330) within Section 3.1.1. The authors are encouraged to vary the wording to improve readability and avoid redundancy. Consider rephrasing or using synonyms to maintain clarity while enhancing the flow of the text.
Author Response
注释 1：短语“土壤背景值”在手稿中重复多次，特别是四次，在第 3.1.1 节的同一段落（第 319 行至第 330 行）中。鼓励作者改变措辞以提高可读性并避免冗余。考虑改写或使用同义词以保持清晰，同时增强文本的流畅性。
回应 1：谢谢你指出这一点。我们根据要求减少了重复内容并提高了此段落的可读性。P9，L319。
在从湖泊沉积物中收集重金属数据时，还记录了参考出版物中提供的环境背景值。对于缺乏此类参考值的湖泊，使用区域土壤背景水平作为替代。在整个数据集中，镉 （Cd） 的平均浓度持续升高，61 个湖泊中有 57 个湖泊 （93.4%） 的 Cd 水平超过了相应的基线阈值。除了 Cd，锌 （Zn）、铜 （Cu） 和铅 （Pb） 污染也达到了令人担忧的水平。具体来说，59 个湖泊的锌浓度超过参考值 （83.1%），而在 77.5% 的调查地点观察到铜和铅含量升高。相比之下，铬 （Cr） 污染似乎不那么严重：在有可用 Cr 数据的 66 个湖泊中，只有 36 个湖泊 （54.5%） 的浓度高于自然本底水平。
