Wildfires as a Source of PAHs in Surface Waters of Background Areas (Lake Baikal, Russia)

Round 1

Reviewer 1 Report

Please see attached file.

Comments for author File: Comments.pdf

Author Response

The Authors thank the Reviewer for the time devoted to reviewing the manuscript as well as for questions and valuable comments.

Author Response File: Author Response.docx

Reviewer 2 Report

This manuscript presents PAHs in the water and aerosol samples of Lake Baikal from 2015 to 2020 and access the ecological risk. This work is carefully done and the findings are of considerable interest. However, the paper needs very significant improvement before acceptance for publication.

There are some grammar and format problems. For examples,

Line 14: We were determined-We determined

Line 258: PAHs were detected in the range of ƩPAH concentrations from 15 to 45 ng/L-ƩPAH concentrations ranged from 15 to 45 ng/L.

Line19: Lack a space between data and units.

Figure 2: The font size is not unified.

Reference in Table S1 were not shown in Supplementary Information.

The author should check the manuscript carefully and improve the manuscript quality.

 

Abstract:

At present, abstract does not well summarize the content of this manuscript. It mainly describes the total concentrations of PAHs. How does PAHs concentrations change in different seasons? Which monomer is at the highest level? These should also be reflected in the manuscript.

Line 17: How many PAHs were detected? The kinds of detected PAHs should be described.

Introduction

Line 66-69: Are these descriptions speculative or refer the literature? If these descriptions refer the literature, please add references here.

Materials and methods

Line 121-123: There is no quality control data of PCBs.

Line 129: What is the LOQ calculation method?

Line 134: Could you show the operational definition of "laboratory precision"? (e. g., must be RSD)

Line 137-138: The parameters in the TEQ equation should be given the units.

Line 146-147: RQs have not units, the author should check it.

Discussion

At present, there is some confusion in the discussion, the thinking is not very clear, and further adjustment is needed. For example,

(1) Water samples from deep horizons and tributaries should be listed separately as a section, otherwise they do not correspond to sampling sites.

(2) The discussion of individual PAHs should be added to the section 3.1 and 3.2, and should not be withdrawn in 3.3. Section 3.3 should focus on comparing PAHs of different media and different seasons to analyzing wildfire effects on surface water quality.

(3) The content of line 204-206 belongs to section 3.1 and should be placed here.

(4) PCBs are also determined in this manuscript, but the abstract and introduction are not described. The content of PCBs was a little abrupt. It can be considered to put this part in SI and focus on the concentration of PAHs.

Figure 3: figure a, b and c should be put in order.

Line 313-316: Are these descriptions speculative or refer the literature. If these descriptions refer the literature, please add references.

Figure 5: What is Ʃ₈ПАУ concentrations in figure caption?

Comments for author File: Comments.pdf

Author Response

The Authors thank the Reviewer for the time devoted to reviewing the manuscript as well as for questions and valuable comments.

Author Response File: Author Response.docx

Reviewer 3 Report

I have read and evaluated the manuscript by Gorshkov et al. on the contributory effects of wildfires on the distribution of PAHs in surface water of Lake Baikal in Russia. The work is interesting. However, there are some grey areas that must be addressed before the manuscript can be acceptable for publication in Water. 

1. Line 51-53. What do the authors mean by "systematic monitoring"? Does this in any way mean chronological or temporal analysis? In that case, the phrase should be revised as there are many previously reported works on levels of PAHs in the same Lake (see the following papers:  https://doi.org/10.1080/10406638.2013.764540; https://doi.org/10.1080/02757540.2017.1393533; https://doi.org/10.3103/S1068373915030085).
2. Line 85-86. June to September of each year from 2015 to 2020? Please be specific.
3. Line 85-86. Figures are supposed to be mentioned (numbered) consecutively).
4. Line 107-110. Some results are presented together with the map of the lake alongside the description of the study area in the Materials and Methods section. Presentation and discussion of results should be done in the Results and Discussion section. 
5. Line 96-101. How was PAHs extracted from the filters for aerosol samples?
6. As the authors analyzed leached runoffs from soils where wildfires occurred, it is expected that other pyrolyzed organics were present in the water samples and extracted samples. How did the authors eliminate interferences. Was clean-up procedure carried out? 
7. Line 326. The Table is not numbered. Secondly, the authors captioned the Table as "PAH concentrations in the surface water of the world", but failed to provide enough geographically representative data (e.g. America/Africa). The authors should consider revising the Table and add PAH data from the following papers: https://doi.org/10.1007/s00244-015-0136-9; https://doi.org/10.1007/s10661-015-5038-9;  https://doi.org/10.1016/j.marpolbul.2016.12.058.
8. The conclusion looks more like a summary. It should be re-written to address the main objectives of the work stated in line 73-81. 
9. The abstract should be revised. in contains unexplained abbreviations (Line 13) and wrong grammar (Line 14). 

Author Response

The Authors thank the Reviewer for the time devoted to reviewing the manuscript as well as for questions and valuable comments.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

It can be accepted in current version.

Reviewer 3 Report

The authors seem to have addressed my concerns. Minor typo and grammar checks may be required before final publication.