Atmospheric Pollution Particulate Matter Absorption Efficiency by Bryophytes in Laboratory Conditions

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Editor/Authors,

The manuscript entitled “Atmosphere pollution Particulate Matter absorption efficiency by bryophytes in laboratory conditions” deals with the estimation of the possibility of using mosses for particle removal from air, in laboratory-controlled conditions. The topic of the study is extremely interesting, novel, and of interest to the broader community, scientists and technologists, policymakers, and practitioners. However, the experimental design is rather naive and modestly performed. I know that this kind of experiment is complex since the tests (or experiments, as the authors said) must be repeated in the same manner. However, the PM was manually injected, and I do not know how it can be repeatably. Then, the cleaning of the particles inside of chamber between the consecutive tests must be carefully done to achieve the same pre-conditions for each test. The English of the manuscript in some descriptions is not proper, and it should be checked by professionals. To summarize, this manuscript must be seriously revised upon the below-listed remarks, and in general, major revisions are necessary.

38 line: resulting currently in more ..

39: PM is not a source of air pollution; it is a pollutant, but a source of PM could be natural and anthropogenic. Please rewrite the sentence.

Fig.1 is too simplified and does not reflect the complexity of air movement in the condition of urban topography, although I suppose what the authors want to say.

98: "Contrary" instead of "Moreover" since the results of the two described studies were not similar.

148: Please provide the name of the moss cultivation company

164: Specify more details about the chamber…what is the form – cubic? How did you disperse the particles…by nebulizer or?  What about the quantity of particles per injection? Then, what is the power of the fan? How did you clean the chamber between repeated experiments (since some quantity of particles have to be attached to the chamber walls)...by air flow or washing? Whether measured in parallel, both fractions, PM2.5 and PM10, on one device?

Figure 4. Mark the direction of air flow with an arrow

206: And, what about the results of validation? Was it an agreement between LOAC and Pollutrack measurements? Provide this info.

213: 13 tests/probes instead of 13 experiments

Fig. 5c should be uniform with the other graphs in the Figure. Also, the correct is PM2.5, not PM2,5.

Table 2: Use a dot instead of a comma in numbers. Why not mark experiments (tests) from 1 to 13? Why, for both wind speeds, did you not repeat the tests with the same reference materials? There was not enough Granit material to be tested with the higher wind speed.

Similar Tables should be provided for the rest of three tested species…and these tables are rather for the Supplementary material.

I do not understand why Thuja was chosen as a control species. This is a coniferous plant and its leaves also have with complex, rough surface. I would understand that you have chosen the species with smooth leaves…

Table 3. I understand that due to some practical reasons, you did not have the same number of tests for each species, but it certainly affects the average value of estimated efficiency for the species tested… Latin name of species: name of genus is with the first capital letter while the species name starts with a small first letter (e.g., Thuja plicata…correct this.

274-275: is injected directly towards the moss tile (distance between, 200 cm). This statement fits more in the 2.2 subsection. And all technical details about the experimental design should be in this subsection.

Since there is a Results section, Figure 6 should be moved there.

Figure 6. The chart title looks like a Figure caption. Please, make it shorter. Use a dot in PM2.5. Scale both axes and specify axes titles. The trend line between only two data sets makes no sense.

284: I can not understand how the injection was done manually. By hand? Please specify the procedure.

289-302: Honestly, the proper validation setup would be if you set in parallel, Pollutrack and LOAC within the same tests. Thus, in separate tests, you can not guarantee that you repeated all conditions and used only different particulate monitors.

303: “Squares represent the error bars.” Error bars should be presented as error lines with stops…

338: highest efficiency

Comments on the Quality of English Language

The English of the manuscript in some descriptions is not proper, and it should be checked by professionals. 

Author Response

Hello! Thanks a lot for your review and concrete suggestion, which are really helpful.

1. Changed.
2. You are absolutely right, it is rephrased.
3. Yes, definately, this image is good to represent the rationale of our experiment and further application of mosses, but do not represent the whole complexity of air pollution transport.
4. Changed.
5. Added, line 151.
6. Rewritten with more details.
7. Figure updated with air flow direction (fan was placed to create traction, not wind).
8. Yes, overall it validates Pollutrack result, but also depicts more information than Pollutrack.
9. Changed accross the Article.
10. Changed.
11. Corrected. We used Iceland dust and Granit, as there was not enough Iceland dust. From physics point of view (to count particles) it is possible to use different pollution sources. Tables revised (added for missing species) and moved to Supplementary material.
12. We totally agree with you, that thuja from biology perspective was not the right choice and can't really be compared with non-vascular plant. However we wanted to show that most popular vegeation for hedges in Europe doesn't really give the benefit of air pollution barrier. And at the same time to show alternative, innovative solution - to build moss walls for pollution absorbtion. 
13. Well noted, to make results justified and comperable, we reduced amount of test for each moss species to 6. For Dicranum Scoparium we removed 7 tests by this rationale - we calculated average efficiency for each test and removed 3 with the highest result of all and 4 with the lowest results of all. Therefore leftover tests represent the mean. For Plagiomnium affine we removed 1 test that had the lowest results of all (average efficiency per test). Therefore now there is the same amount of tests to compare and average efficiency results changed slightly, which is now represented within the whole Article.
14. Statement moved to Methods body paragraph.
15. At first it was moved to Results section, but after we added ANOVA test, it was removed at all from the article. We added ANOVA test for justification of results, after we reduced test amounts to 6 for each moss species, we were able to do more statistical analysis.
16. This figure was removed.
17. Yes, it was done manually by hand neubilizer. We used same amount of pollution (1g) each time.
18. Added extra information in the paragraph. We conducted LOAC test together with Pollutrack session.

Thank you again for delving in our paper, your comments and suggestion really made an impact on enhacing the Article. Hope all the questions were answered, if not, please do not hestitate to contact us.

 

Have a great day,

BR,

Juta.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

Your paper is very good and valuable in its own context. There are few comments you need to consider, particularly doing statistical analysis for supporting your results and selecting Plagiomnium affine with highest efficiency. Below are detailed comments.

 

Introduction

This section well-structured and almost perfect, however there are few minor points to consider:

1. In line 85, I think the sentence “However, there is limited knowledge about the microbes associated with mosses [72-74], and further research must be done [75].” should be removed as it has no relation with your work, and you can’t propose that more research must be done about the microbes associated with mosses.
2. One of your aims is “Can mosses absorb air pollution PM2,5 and PM10 in a laboratory setting”, how this comes as an aim where before this you mentioned in introduction that many different studies confirmed the ability of mosses in capturing particles. If laboratory condition is your point, you should explain it in the introduction.
3. There are more than 80 references in this section. Many citations may address common or widely accepted facts that do not require extensive referencing. So please consider removing those cited to support the same point unnecessarily.

 

Materials and Methods

This section covers necessary parts, but there are a minor and major points here:

1. Number of tests are unclear in below sentence ”One tile was prepared for each species and tested repeatedly.” Line 158.
2. Also, I believe an analysis part should be here. Although one of your aims was “what is the average efficiency of moss species Dicranum scoparium, 126 Plagiomnium affine, and Hypnum cupressiforme in a vertical position?” however, in the results section you did compare these species, but how? Moreover, you have a control treatment, so what is that for? If you want to compare the species efficiency you have to do proper statistical analysis, like three T.test (control vs moss sp1 - control vs moss sp1 - control vs moss sp1) or ANOVA test (compare all treatments together if you want to select more efficient species). This way you can present a clear statistical significancy and proper parameters like p-values and confidence intervals.

 

Results

1. First paragraph of this section is NOT results, and just repeated of what you did. Also please provide a clear figure caption instead of explaining the figure axis in the text. Please consider rewriting this section.
2. Performing appropriate statistical analyses to test differences in efficiency among moss species and the control is lack. My point in methods section is more obvious here, particularly in Figure 5 which shows efficiency results graphically for each moss species and the control (Thuja plicata) across multiple experiments. However, there is no indication of formal statistical comparisons between the control and the moss species, nor is there clear statistical presented.
3. Why a different number of replicates were conducted for each species. You did not provide a clear justification or explanation for these variations. How these differences in experimental numbers impact the reliability of the results?
4. What is the reason of the negative efficiency observed in the control experiments with Thuja plicata?

 

I have no comment for discussion section. There is no suitable statistical analysis to support that the species you select has the highest efficiency if this experiment be repeated many times.

Author Response

Hello! Thanks a lot for the review, it is trully valuable for us to enhance the Article.

Introduction:

1. Well noted, it is removed.
2. Added, line 104-109.
3. Removed around 10 references.

Materials and methods:

1. Explained in the text, line 161-162.
2. This was very valuable suggestion, we added ANOVA test and it suits very well in this situation. Its results are added within Results section.

Results

1. Revised and changed.
2. Taken into account and lots of changes in this body paragraph (added ANOVA test results, removed Dicranum Scoparium results in table, moved it to Supplementary material together with all the rest species).
3. Well noted, to make results justified and comperable, we reduced amount of test for each moss species to 6. For Dicranum Scoparium we removed 7 tests by this rationale - we calculated average efficiency for each test and removed 3 with the highest result of all and 4 with the lowest results of all. Therefore leftover tests represent the mean. For Plagiomnium affine we removed 1 test that had the lowest results of all (average efficiency per test). Therefore now there is the same amount of tests to compare and average efficiency results changed slightly, which is now represented within the whole Article.
4. Basically there is a pollution already in thujas, as thujas were taken from the hedge in Orleans (France) suburbs. The force of traction created by the fan, pulled out excisting pollution and together with injected pollution it made 2nd sensor (after the vegetation) to catch more pollution than first one. As first sensor cought only injected pollution, but second one all the pollution (injected and pollution from vegetation).

Thanks a lot again for your review, 

hope all questions were answered, if not, please let us know.

 

BR,

Juta.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear author,

 

Although, you changed the manuscript mostly according to the given remark but I still have some comments:

I have not seen that you changed Figure 1.

Please use the mathematical format of unit recording m s-1 instead of m/s throughout the manuscript. This is more scientific. Slashes are often associated with `or`. In addition, there is a space between the number and the unit.

Figure 4. has still been improved…you can add dimension up to moss wall, and after…on which position from the wall is k? The moss wall should be represented with the 3^rd dimension, a width of the chamber.

In the text, add the material from which the chamber is made.

Figure 5. The graphs lack x and Z axes. Please, provide it together with axes titles and units.

 

What about the Conclusion section? It is a usual manuscript format, except if the Atmosphere journal does not insists.

Author Response

Comment 1: I have not seen that you changed Figure 1.

Response 1: It has been changed now according to paragraph above it.

Comment 2: Please use the mathematical format of unit recording m s-1 instead of m/s throughout the manuscript. This is more scientific. Slashes are often associated with `or`. In addition, there is a space between the number and the unit.

Response 2: Updated throughout the Article.

Comment 3: Figure 4. has still been improved…you can add dimension up to moss wall, and after…on which position from the wall is k? The moss wall should be represented with the 3^rd dimension, a width of the chamber.

Response 3: It has been updated.

Comment 4: In the text, add the material from which the chamber is made.

Response 4: Added in lines 157-161.

Comment 5: Figure 5. The graphs lack x and Z axes. Please, provide it together with axes titles and units.

Response 5: Figure 5 updated accordingly.

Comment 6: What about the Conclusion section? It is a usual manuscript format, except if the Atmosphere journal does not insist.

Response 6: As per guidelines, the Conclusion section is optional, and in this Article's case, we believe that the Discussion reveals the whole interpretation of the results, is quite simple, and doesn't require an extra summary. Do you agree? If not, please let us know, and we will prepare the Conclusion paragraph.

Thanks a lot for your quick and constructive feedback,

have a great new week,

BR,

Juta.

 

Author Response File: Author Response.pdf