A Study on the Measurement of Unregulated Pollutants in Korean Residential Environments

Round 1

Reviewer 1 Report

Thank the authors for their patiently reviewing the comments and most of the comments have been addressed properly. I think the revised version is now in a much better shape. However, some of the previous questions were not answered properly, and to make it clearer and easier to be followed by the readers, some improvements still need to be done. Additionally, the point-to-point responses to the reviewers’ comments (as required by the journal, https://www.mdpi.com/authors/layout) were missing. Besides, when making revisions, it is suggested to use the “track changes” feature in Microsoft Word. The “compare” function in Word can add tracked changes to the final version by comparing it with an earlier version (see chapter 10 in https://www.mdpi.com/authors/layout). The following detailed comments could help the authors to revise the paper.

Abstract

• “14 substances out of the 16 analyzed chemicals were detected and, among them, the concentrations of phenol, α-pinene, and limonene within the indoor air were high… Among the terpenes, α-pinene and limonene were detected, of which the highest concentrations were as 598.2 ug/m³ and 652.5 ug/m³, respectively”. The authors were suggested not mention “terpenes” here, which makes the sentences confusing.
• “the reason for high the concentrations of the two substances…” should be “the reason for the high concentrations of the two substances…”, and “wood use should be reduced” is better to be “the usage of wood should be reduced”

Introduction

• Page 1 line 51-53: “Therefore, this study measured …. and identified new indoor pollutants that could cause sick house syndrome”. Which new indoor pollutants are identified by this study? Do the authors mean “phenol, α-pinene, and limonene”? they are not new indoor pollutants identified by this study, they have been measured and analyzed before by previous studies.

Method

• For Table 3, is the classification important? If so,  please add related discerptions in section 2.2. If the classification is not important, then do not mention them, they make the results section sound complicated. It will be better to add the corresponding reference behind these chemicals since the authors said they were mentioned in previous studies.

• For Table 4 the conditions of GC/MS, the information presented is still not clear. What is the meaning of the first row (Automatic Thermal Desorption PerkinElner Turbo Matrix ATD) and fourth row (Gas Chromatography-Mass Spectrometry Agilent GC/MS 6890N/5973inert)? Isn’t the whole table about Gas Chromatography/ Mass Spectrometry? Is the fourth row about a particulate aspect of the GC/MS? It is confusing. More description is needed in the text, as the authors did for the “chromatographic column”. For the GC oven temperature, (35 ˚C（2 min）→15 ˚C/min→95 ˚C→5 ˚C /min→105 ˚C →5 ˚C /min→250 ˚C (5min) ), why not mention time durations for all 95 ˚C and 105 ˚C? Besides, the units of “15 ˚C/min”, “2.5 ˚C/min”, and “5 ˚C/min” look weird. Do the authors mean one minute for these temperatures? This analysis method is not commonly used in the field of buildings, so the authors should explain it more carefully. (by the way, it is better to change the “Temp.” in the third row to “temp.”, to keep them the same)

Results

• Please check the English carefully. Some sentences need to be improved or rephrased. For example, “the indoor air concentration of acetone was 31.0-83.4 ug/m³” is better to be “the concentration range of acetone in the indoor air was 31.0-83.4 ug/m³” (line 118); “the B house measured in Daegu had 402.5 ug/m³, which was the highest concentration among the houses measured” is better to be “the highest concentration was 402.5 ug/m³, which was found in House B in Daegu” (line 120); “which was low” should be “which were low ”(line 127); etc.

• Page 5 line 124-126, “It was important to identify whether houses with high concentrations of chemicals in the indoor air used vinyl flooring or vinyl wallpaper as an indoor finishing material.” Why suddenly mention this sentence here? What is the connection between this and the context?

• For figures 1-4, they are suggested to be combined as one figure, and there is no need to separate them into different categories since the authors didn’t mention anything about the categories when they describe the related results (section 3.1).

• Page 6 lines 223 -225 ‘Phenol was measured at a level that was 2.51 times higher than the LCI, while the terpenes, α-pinene and limonene were 2.39 and 2.18 times higher, respectively“. First, this is not accurate, it’s easy to cause misunderstanding. The maximum results cannot represent the whole measurement results, as the authors mentioned in section 3.1 “The average concentration of phenol … showing differences in concentration depending on the housing”. If the authors must select a value to compare with the standard, then the average value is better than the max, because the average could represent the group while the maximum can only represent one. Or the authors could add the average in table 5, and explain more in the text, for example, “the average concentration of phenol was 23.8 ug/m³, which is higher than the LCI value -20 ug/m³. As shown in Figure 1, the measured values of phenol in six houses exceeded this value…”. Second, it’s better not to mention terpenes here, because “while the terpenes, α-pinene and limonene were 2.39 and 2.18 times higher, respectively” sounds really confusing. Lastly, the English expression of this section also needs to be improved.

Discussion

• Page 7 line 232, “14 of the 16 chemicals analyzed were detected”, according to figures 1-4, only 13 of them were detected. Please check carefully since this is the main finding of this study.
• Please check the English expression, and some sentences were suggested to be rephrased. For example, lines 249-251, lines 161-165, lines 279-28, 1ect.
• Page 7 lines 238-239, what’s the purpose of mentioning the physical and chemical properties of phenol?
• Page 8 lines 286-287 “If the processing and drying period of wood are adjusted, the amount of terpenes emitted from the wood can be reduced”, is there any theoretical basis? Any references?

Conclusion

• First check the result, according to the results, P-cymene was also below the detection limit.
• Second, only mention the most important finding of this study. “but TXIB and 3-292 caren were below the detection limit” can be deleted since this is not important, these two chemicals were rarely mentioned in the whole paper.
• The structure should be rearranged. One suggestion could be: This study evaluated the contamination of unregulated chemicals in Korean houses. Of the 16 analyzed chemicals, 13 unregulated chemicals were detected. Among them, the average concentrations of phenol (23.8 ug/m³), α-pinene (), and limonene () were higher than their LCI concentrations, and the maximum concentrations of chemicals were found to be more than twice their LCI levels. According to this study, these chemicals should be ….
• The last sentence (lines 299-302) is better to be rephrased.

Author Response

We appreciate your kind comments.
We learned a lot from your comments while revising the content of the manuscript.

We thank you once again for your contribution, and we will try to publish a new article in Buildings.

Author Response File: Author Response.pdf

Reviewer 2 Report

Aim of the  work is to study the pollution caused by unregulated chemical substances in Korean residential environments. Some improvements are required:

• provide for a brief (only two sentences) issues' introduction in the Abstract and add the methodology used
• provide for a more in-dept conclusions and discussion of the results
• make clearer the description of the applied method
• add the innovative contribution of the work to the existing knowledge on the topic. Some references could be: Morano, P., Guarnaccia, C., Tajani, F., Di Liddo, F., & Anelli, D. (2020, September). An analysis of the noise pollution influence on the housing prices in the central area of the city of Bari. In Journal of Physics: Conference Series (Vol. 1603, No. 1, p. 012027). IOP Publishing and Mínguez, R., Montero, J. M., & Fernández-Avilés, G. (2013). Measuring the impact of pollution on property prices in Madrid: objective versus subjective pollution indicators in spatial models. Journal of Geographical Systems, 15(2), 169-191.

Author Response

We appreciate your kind comments.
We learned a lot from your comments while revising the content of the paper. We thank you once again for your contribution, and we will try to publish a new article in Buildings.

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

This paper presents concentrations of 16 indoor pollutants in 11 Korean residential houses. The intentions of conducting such a measurement is good, however, this study is short of innovation. The sample size is too small to get any statistical/general conclusion. It looks like a report rather than a scientific paper. Besides, the topic is not suitable for this journal, it focus more on chemistry, instead of buildings. Last but not least, the English writing of this paper need to be improved. The following detailed comments could help the authors to revise the paper.

Abstract

• In the abstract, the authors are suggested to show the most important findings and conclusion of this study, and not just show the numbers. Please explain the meaning behind the numbers. In addition, try not to use acronyms in the abstract, such as TXIB and LCI.

Introduction

• Page 1 line 51-53: “Therefore, this study measured pollutant chemicals in a new residential environment in Korea and identified new indoor pollutants that could affect residents' health”. Which new indoor pollutants are identified by this study?

Outline of research

• The method is not clear enough. Why and how did the authors select these pollutants? In table 1, 16 pollutants were presented, however only 10 of them were mentioned in the previous paragraphs. Why did the author also select the other six (such as phenol, 3-carene)?
• For Table 1, why did the authors classify the chemicals in this way? What is the basis of classification? the authors didn’t mention the categories in the text at all. Besides, the authors should mention CAS is chemical abstracts service in the note below this table.
• For Table 2, the information presented is not clear. What is ATD? What is the meaning of the third row (GC/MS Agilent GC/MS 6890N/5973inert)? What is HP-VOC? For the fifth row (35 ˚C（2 min）→15 ˚C/min→95 ˚C→5 ˚C /min→105 ˚C →5 ˚C /min→250 ˚C (5min) ), why not mention time duration for all the temperature?  This analysis method is not commonly used in the field of buildings, so the authors should explain it more carefully.
• For section 2.3, the selection of housing is not clear either. What is the selection principle? Why only select one in Andong, while seven in Daegu? Additionally, the sample size is small, therefore, it’s difficult to get any statistical results. The four RH houses selected in this study cannot represent the performance of all this kind of houses because the sample size is too small.
• Two small commons: 1, please check the English, for example lines 57-58, line 77, line 86-87 (it is not correct to say “…were measured/detected a low/high concentration…”), line 133-134 (“the room at a height of 1.2-1.5 m above the floor” is not a complete sentence). 2, for the acronyms, such as VOC (line 33 and line 55) and HB Mark (line 42 and line 118), their full names only need to be mentioned once at the first place, then they can be used directly. That’s the point of using acronyms.
• For Table 4, it would be better to add one more column of “resident”, and why not mention the number of residents for Non-RH houses, and the status of furniture, sinks, and tables for Rh houses?

Results

• For some chemicals, the concentration ranges were mentions, for some (e.g., 2-butanone, α-pinene), they were not, why? Same questions for max and average values. The way results are presented should be improved.

Discussion

• Like mentioned before, the sample size is too small, the four/seven RH/Non-RH houses selected in this study cannot represent whole houses in these two categories. Therefore, the comparisons are untenable. For example, “With regard to Texanol, 2- (2-Butoxyethoxy ethanol), Camphene, Dichloromethane, Tridecane, and 1,2,4-Trimethylbenzene, Non-RH houses were measured 1.1 to 1.9 times higher than those of RH houses”, this is not 100% correct, because the concentration of Texanol in most RH house (A,B,D) were lower than that in most Non-RH houses (A,B,C,E) .

Conclusion

• Same as the abstract, in the conclusion part, only the most important findings/conclusions should be mentioned. Try to interpret your findings at a higher level. Do not simple summarize the results that were already presented in the body of this paper.

Comments for author File: Comments.docx

Reviewer 2 Report

This manuscript mainly focuses on several indoor gases that may be harmful to human body which without the regulated of building standards, and carries out experimental measurement research. The study found that there was a higher concentration of pollution gas in the non-regulated houses than in the regulated houses. This is a very meaningful study, but there are still some problems in the study. After correcting these problems, it will be more conducive to be accepted of the manuscript.
1.    The abstract needs to be optimized. overemphasizing the research results is not conducive to readers' understanding of the article, and it is suggested that the proportion of each part of the article in the abstract should be redistributed, so that the structure of the abstract is more reasonable and beneficial to readers' understanding of the research.
2.    The language logic in lines 55-58 is unclear and it is recommended to revise;
3.    In line 59, the author mentioned the new sick house syndrome, which seems to be the principle of selecting harmful gases that are non-regulated in the follow-up research. So why the harmful gases selected in this paper are REPRESENTATIVE?
4.    In line 87, the put forward of wooden house has its particularity. is it the basis for the author to choose the follow-up experimental house?
5.    In describing the harmful gas, only the harm of gas is simply described, and the threshold concentration at which the harm is caused to the gas is not mentioned.
6.    What is the basis for the study to select the completion time of the house? It is found that the supervised houses in this paper were completed earlier-does this lead to lower concentration of harmful gases in the results?
7.    Why is a differential concentration analysis given for only a portion of the harmful gases in the results?
8.    The error bar needs to be given in the experiment result diagrams (Figure 1 - 4).
9.    The discussion needs to be improved. The difference between RH and Non-RH results should be due to the construction and finishing style of the house. The writing in this paper is more likely to mislead readers to think that the reasons for the differences are "house regulation", rather than more specific scientific issues.

Reviewer 3 Report

Dear authors

The research topic, A study on the measurement of unregulated pollutants in Korean Residential Environment, is interested but it is quite challenged to publish with current forms.

First this study could not find special novelties and contributions compared to other similar results founded. This study just describe the measurement data. If there is special methods to improve the indoor air quality or reduction skill of the pollutants, this study can be more specialized. 

Second, Table 5 and 6 should move to Result parts.  In general, discussion parts describe special results parts with authors critical thinking.  However, this discussion showed new results with the tables. 

Third, the following results that measured indoor air pollutants represent typical Korean residential buildings' pollution level? It has special methods to reduce the pollutants with new filters or ventilation strategies? Each test rooms measured air ventilation rate? if it is not, why these results have worthy to present? 

Last, it is very challenged to read the paper smoothly.  The most sentences are written with the passive voice.  Please update the English writing professionally because many grammar errors are founded as well.