Physicochemical Characterization of Air Pollution Particulate Matter (PM_2.5 and PM_>2.5) in an Urban Area of Cotonou, Benin

Round 1

Reviewer 1 Report

The paper is an interesting contribution to the related field. Some recommendations on how to improve the manuscript is offered below:

1)    In page 2; line 62-64: Author reported that “….., Pacenti et al. (2009) reported that the main PM source is vehicle exhaust emission…” That reference is too old and the statement is not enough. Besides, there are many recent literatures that describe and investigate the genesis of PM, PAHs, OC, EC and other particulate emissions from different engines and link their effects to human health. I suggest that authors should increase more recent literature and correspondence in that regard to support their discussion. Kindly fill those gaps with 10.1016/j.energy.2021.121837.

2)    The methodology of the present study is innovative but kindly includes the schematic diagram of the research process within the context for better readability.

3)    Instead of reporting what other researchers have done in section 3, I suggest that the authors should give more details in the confrontation of their results. Also, the result trend should be compared with the recent existing literature.

4)   Before the conclusion section, kindly add sub-heading with some discussion or recommendations on how those emissions you investigated could be reduced.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

This study is a study on the physicochemical characteristics of particulate matter, which may be meaningful as data, but the sampling year was too long ago to 2010, lacks novelty.  

Change the references in the text according to the guidance of the journal. 

L.85-L.86. Is sampling year 2010 right?

 Looking at the references in Tables 1 and 3, all years are different, and it is questionable whether they can be compared equally with the results of this study. 

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The presentation of the research paper is significantly improved. However, it can be accepted in the present form. Thank you.

Reviewer 2 Report

The authors have made extensive revisions to their papers and now have reached the publication level of the atmosphere journal.