Urban Air Quality Monitoring in Decarbonization Context; Case Study—Traditional Coal Mining Area, Petroșani, Romania

Round 1

Reviewer 1 Report

The article “Urban air quality monitoring in decarbonization context. Case study - traditional coal mining area, Petroșani – Romania” is focused on an experiment performed for the monitoring of some air pollutants in a coal mining area of Romania. Through the use of “low-cost” instruments, the authors have measured the concentrations of NO, NO2, SO2, CO, CO2, PM10, PM2.5, PM1, and TSP in six different locations. Moreover, their measurements have been compared with the data coming from a monitoring station of the “Romanian National Air Quality Monitoring Network” located roughly few kilometers far away. The term “low-cost” instruments is here used to distinguish the technology of the instruments used by the authors, which is based on gas or gaseous compound sensors, from the regulatory technology featuring fixed monitoring stations of the “Romanian National Air Quality Monitoring Network”.  Gas sensor based devices are cheaper compared with regulatory instruments, but provide less accurate measurements, although in heavy, or medium-heavy polluted environment, the data produced by such devices can be considered with a reasonable level of reliability. Having exposed this necessary premise, the article appears to be well structured. The introduction gives a clear overview of the issue, and the results are exposed with a good level of clarity. The conclusions are correctly inferred. However, the article needs several minor improvements before publication, because the document presents a poor readability. The author must pay more attention to the punctuation, and in general, English writing style should be more readable with shorter and clearer phrases. Moreover, in more parts of the document several grammar errors are present. Here below, some suggestions to improve the manuscript are exposed.

Line 16: it should be, “In this paper, the main air pollution sources of Petroșani are identified, and the performed measurements emphasize the air quality in the area of its transit road”.

Line 17: could be better: “ the frequency and duration of the program, and other monitoring parameters.”

Line 20: it is better: by the “National Institute for Research and Development in Mine Safety 20 and Protection to Explosion”

Line 21: missed article: the “University of Petroșani”

 

Line 25: missed article: Based on the variation of THE measured values…

 

Line 31: missed article: to THE military…

 

Line 54: it should be: that makes

 

Line 100 and 102: it should be: tons, not tones

 

Line 105: it should be: “have been heating”

 

Line 106: the phrase is a little bit confusing, maybe you meant: often through several pre-existing installations in each building… please, improve this phrase…

 

Line 129: maybe you meant and instead of end…

 

Line 145: the phrase is a little bit confusing, maybe the author meant “the experiment purposes, such as: pollution spreading area, level of pollution, or short-term concentrations.”??

 

Line 171: article missed: According to the No. 104/2011 Law on the ambient air quality, sampling points were placed

 

Line 172: it should be: “to avoid the microenvironment measurement effects, so that the obtained values result to be of proven  relevance for the air quality”

 

Line 174: this phrase is confusing, maybe the author meant: “The sampling port was placed a few  meters away from buildings, trees or other obstacles, so that an area of 270 was clear from any interfering object”???

 

Line 177: maybe the author meant: the particulate matter sampling was placed…

 

Line 196: maybe the author meant: It is possible to select 25 different indoor air quality….

 

Line 223: it should be: based on the established knowledge at the time

 

Line 278: it should be: “can be found”

Line 285: it should be: “As it can be seen in figure 8”

Line 336: it should be: “we have found that”

Line 347: it should be: “for catching”

Line 349: it should be “in different weather conditions”

Line 356: it should be “suggests”

Lines 355-361: I suggest the author to split this long phrase into shorter ones for better manuscript readability.

Line 364: it should be: “it is expected”

Table1: the author must clarify why some values are marked in red.

Line 366-369: the phrase is very confused, please, I invite the author to reformulate it for a better document readability

Lines 336 – 342: the author must pay more attention to the punctuation and also I suggest to split this very long phrase into shorter ones, for a better manuscript readability.

Line 364-365: the author must pay more attention to the punctuation for a better document readability, for example, it should be: “In the energetic mining sector, even if it is expected that the decarbonization process will slow down, diminish or even stop, the fossil fuels burning still remain a necessity.”

Comments for author File: Comments.pdf

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript tried to evaluate the air quality and identify the potential sources of pollution in Petroșani, a traditional mining region from Jiu Valley bituminous coal basin of Romania. The relevant studies and monitoring data are quite few due to the less investigation in this region, as a result, the information provided by this manuscript will be helpful for readers to understand the status in the special historical Romanian bituminous coal mining basins. However, the overall data analysis of the manuscript is not sufficient, the experimental design is less reasonable, and the conclusion is not logical, so, it’s suggested the major revisions should be made by authors to improve the quality.

The major issues were listed for reference as following:

1.      The relevant monitoring instruments selected by this studies are qualified, however, no quality assurance or control (QA/QC) for these instruments were introduced, therefore, the accuracy of monitoring data is questionable.

2.      The six sampling points were located on the road that crosses the city. This is a critical problem concerning about the representative of air quality monitoring.  If the objective of study is to reflect the impact by traffic exhaust or to identify the contribution from traffic pollution, the monitoring site could be set on the roadside or near road area.  Shown by the concentrations of pollutants on Table 1, the most high values of NO or NO2 as well as CO even the TSP are quite closely related to vehicle emissions or the fugitive dust by the fleet directly.  However, the following analysis focused on the potential pollution change trends or possible contribution resulting from the decarbonization process. Here is absolutely no comparison between the monitoring data from the roadside (roundabouts) and the national station of HD-5.  The national standard station is usually located  far away from the major traffic road and the inlet of sampling pipe should be 3 meters high at least to avoid the local emission.      

3.      In addition, only one period of sampling data were provided in the year 2020, there was no air monitoring data in the same city in the past year, e,g. the year of 2014 shown by Figure 9. It’s no logical to infer that roadside air quality is worse than the national site resulting from the decline in coal use over the decades. 

4.      There are so many  symbols of “÷” in Table 3 and Table 4. It should be replace by “-” or “~”.

5.      Values in Table 1 are the maximum of pollutants, which is ambiguous. Please explain it’s the hourly maximum or the minute mean or the time resolution. In order to compare with the value in Table 3 of HD-5, it’s suggested to be treat the data by same time resolution.   

6.      The conclusions about the relationship with RH or temperature should be listed or analyzed in the section of discussion.

7.      Please add the site of HD-5 station on the map of Figure 5.

8.      The words from line 217 to line 224 are quite general, it could be moved to the previous introduction or deleted.

9.      Please check the logic of the data to ensure the value of TSP>PM10>PM2.5>PM1 for the same sampling time on the same site in the Table 1.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The revised version is fine and much better, which could be suggested for next step of publishing.