Health Effects of Air-Quality Regulations in Seoul Metropolitan Area: Applying Synthetic Control Method to Controlled-Interrupted Time-Series Analysis

Round 1

Reviewer 1 Report

The manuscript is well written and appropriately organized. I am having a view that it is theoretically sound, and will be helpful in understanding the impact of air pollution on environment and human health. Below are my specific comments, and incorporation of these may enhance the readership of this manuscript.

Comments

Abstract should have few main findings from the study. The basic problem is not clearly mentioned. What is hypothesis behind the presented review manuscript. The presentation fails to discuss the summary, and trying to some of vague reason which is not the explanation. Strengths, limitations, and recommendations of the current study should be demonstrated. what does the paper add to the current literature? and what new knowledge is added by this study? The material and method section is too weak in the manuscript and you need to focus on it more. The explanation for the critical analysis is not sufficient, although some of the good points have has been identified. Conclusions are very generic, and could be tightened up. 

Reference section should be increased with number of recent studies. I would like to suggest to author to include following published article to improve the quality of articles, these are

Gautam S, Tataliya A, Patel M, Chabhadiya K, Pathak P. 2020. Personal exposure to air pollutants from winter season bonfires in rural areas of Gujarat, India. Exposure and Health 12, 89–97. Gautam S, Brema J. 2020. Spatio-temporal variation in the concentration of atmospheric particulate matter: a study in fourth largest urban agglomeration in India. Environmental Technology and Innovation 17 (DoI; 10.1016/j.eti.2019.100546). Gupta A, Gautam S, Mehta N, Patel M, Telatiya A. Association Between Changes in Air Quality and Hospital Admissions During the Holi Festival. SN Applied Sciences 1, 163 (doi.org/10.1007/s42452-019-0165-5). 

Other comments:

English editing is needed in some parts of the manuscript.

Abbreviations should be explained before the introduction.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Review of the manuscript entitled “Health Effects of Air Quality Regulations in Seoul Metropolitan Area: Applying Synthetic Control Method to Controlled Interrupted Time Series Analysis”

General comments:

The manuscript provides methods and evidence of enacting air quality regulation causing health benefits in Seoul Metropolitan Area. The authors have succeeded in quantifying the change in mortality between the pre-intervention and post-intervention periods. However, it is difficult to read and follow the manuscript to understand the construction of the synthetic control group.

There are a few areas that the authors need to clarify in the manuscript.

• Is there any particular reason for using cardiovascular disease mortality rather than other health endpoints such as respiratory diseases mortality ?
• The authors should include the map of the location of sites which are considered to be in the potential control group and the intervention group. Explain the choice of the sites to be in the different groups earlier in the manuscript not later.
• It is helpful to have a table listing the dates of different regulation enacted and implemented in each region or cities.
• For air quality trend, is the effect of meteorology considered or removed ?
• Was consideration give for the proximity of air quality monitoring stations to pollutant sources? For example, are stations used in the study background sites, or roadside, or sites in industrial areas? How might this have affected the results?

I recommend the manuscript to be accepted for publication with some revision to address the above comments and the following specific comments

Specific comments:

• In the introduction, the sentence “Even though there is growing interest about the health effect of air quality regulations in recent, there remains a need for further studies so as to make decision-makers design more effective policies [1,2].” should be changed to

“Even though there is growing interest about the health effect of air quality regulations in recent years, there remains a need for further studies to help decision-makers design more effective policies [1,2].”

• Second paragraph of Introduction, “PM-related budget” should be “PM-related control budget”
• Page 3, second paragraph, sentence beginning “Based on the availability of data…” is not clear
• Please define GRDP for a non-Korean audience
• Page 4, second paragraph: “The NRMSE was calculated by dividing root mean squared error (RMSE) of each variable into the average value of the variable..”, change to

“The NRMSE was calculated by dividing root mean squared error (RMSE) of each variable to the average value of the variable..”

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Thank you for the opportunity to review this manuscript, which I found very interesting and probably scientifically sound. However, it is hard to comment on the results and discussion chapters in the current text, which is confusing in places. 

There are substantial issues with grammar (congruenfcy, tempus, vocabulary), some listed below, but the manuscript should be proofread thuroughly for language.

Specific comments to introduction and the beginning methods.

Introduction

Not so concise

paragraph 2,

too many adjectives, “In South Korea, the exposure to particulate matter (PM) especially became the most serious health problem recently”

PM-related budget? Rather: budget allocated to reduce PM air pollution

Enormous amount of budget -> enormous amount of money? Funds?

Paragraph 3: congruency “Much Many of THE … studies …. used … designS”

Para graph 4:

“The studies in South Korea used a single region as a control group that has similar characteristics with AS an intervention group “

“this study constructED a virtual control group, the ‘synthetic control’, which canCOULD prevent these…”

Past tense and present tense in same sentence,

“this study constructed…” rather “the researchers / we constructed” or use passive voice.

“used type of quasi-experimental study designS”

2: Material and methods

Please state the study period.

Paragraph 2,

“Intervention groups were defined as Seoul and Incheon which are metropolitan cities in Seoul metropolitan area, respectively.” - not clear what “respectively” refers to.

 

Author Response

Please see the attachment

Author Response File: Author Response.docx