Risk Associations between Air Pollution Exposure and Cardiovascular Diseases: A Residential Retrospective Cohort Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The human health problems caused by anthropogenic air pollution have always been a concern. This manuscript provides a reference for analyzing cases of disease mortality caused by PM_2.5 in the valleys of southern Italy. However, the unique terrain (valleys) and local population may result in the conclusions of this manuscript not being universally applicable.

The main problems are as follows.

1. Suggest adding a keyword: 'Italy'.

2. Suggest unifying the relevant keywords, such as "atmospheric pollution" and "air pollution".

3. “The burden of diseases associated with exposure to air pollution is large and growing and has a huge impact on human health;” on line 32-33 is ambiguous. Does “the burden of diseases” or “air pollution” have an impact on “human health”?

4. “The World Health Organization” on line 36 can be abbreviated as WHO. Therefore, everyone knows.

5. The language needs further clarification. For example: “between 4 million and 9 million deaths” on line 41-42 should be “approximately 4 million to 9 million deaths”; “populations” on line 51 should be “residents”; “between 17.1 and 20.2 µg/m³” on line 315 should be “from 17.1 to 20.2 µg/m³”.

6. What's the meaning of “PM” on line 57? Should “PM” be “PM_2.5” ?

7. “scientific” on line 62 is unnecessary.

8. The drawing of Figure 2 and 3 is not standardized.

9. This manuscript only distinguishes the gender structure of the research samples and ignores their age structure, although it was mentioned. This also leads to a deviation in the rationality of the relevant results. Because the elderly are more susceptible to the impact of air pollution.

10. The level division of PM_2.5 in Figure 2 on line 157 is inappropriate, as there is no clear classification of the boundary point values. Besides, are 10 levels too many?

11. The format standardization of this manuscript is poor. Authors need to carefully organize the format.

Comments on the Quality of English Language

Extensive editing of English language required.

Author Response

The human health problems caused by anthropogenic air pollution have always been a concern. This manuscript provides a reference for analyzing cases of disease mortality caused by PM_2.5 in the valleys of southern Italy. However, the unique terrain (valleys) and local population may result in the conclusions of this manuscript not being universally applicable.

We are aware that we have considered a small area and agree with the reviewer that the study area and population are not representative of all locations worldwide but, nevertheless, the study contributes to strengthening the evidence for an association related to the effects of air pollution on the cardiovascular health of exposed individuals.

The main problems are as follows.

1. Suggest adding a keyword: 'Italy'.

We thank the reviewer for the suggestion. We included the keyword Italy.

2. Suggest unifying the relevant keywords, such as "atmospheric pollution" and "air pollution".

We thank the reviewer for the suggestion; we report the keyword “air pollution”.

3. “The burden of diseases associated with exposure to air pollution is large and growing and has a huge impact on human health;” on line 32-33 is ambiguous. Does “the burden of diseases” or “air pollution” have an impact on “human health”?

We thank the reviewer for this observation. We modified the sentence to improve clarity.

4. “The World Health Organization” on line 36 can be abbreviated as WHO. Therefore, everyone knows.

We thank the reviewer for this observation. We modified accordingly.

5. The language needs further clarification. For example: “between 4 million and 9 million deaths” on line 41-42 should be “approximately 4 million to 9 million deaths”; “populations” on line 51 should be “residents”; “between 17.1 and 20.2 µg/m³” on line 315 should be “from 17.1 to 20.2 µg/m³”.

The text has been revised in order to enhance clarity and incorporate feedback from the reviewer.

6. What's the meaning of “PM” on line 57? Should “PM” be “PM_2.5” ?

We thank the reviewer for the opportunity to clarify this. We modified the references so that they are now in line with the text.

7. “scientific” on line 62 is unnecessary.

We agree and delete the word “scientific”.

8. The drawing of Figure 2 and 3 is not standardized.

We thank the reviewer for this observation. We standardized figures 2 and 3.

9. This manuscript only distinguishes the gender structure of the research samples and ignores their age structure, although it was mentioned. This also leads to a deviation in the rationality of the relevant results. Because the elderly are more susceptible to the impact of air pollution.

We agree with the reviewer that elderly are more susceptible to the impact of air pollution and precisely, in order to take into account the age-class structure we provided risk associations between air pollution and cardiovascular diseases considering the risks associated with increasing age classes. To do this we adjusted for age groups, as specified in paragraph 2. We rewrote the paragraph to improve clarity.

10. The level division of PM_2.5 in Figure 2 on line 157 is inappropriate, as there is no clear classification of the boundary point values. Besides, are 10 levels too many?

We thank the reviewer for the comment and the opportunity to better clarify our work. The purpose of Figure 2 is to highlight the PM_2.5 distribution in the study area. To do this we used the equal-interval classification method. This method divides the range of attribute values into subranges of equal size: you specify the number of intervals (or subranges), and the data is divided automatically. We then chose the number of classes that most closely matched the continuous distribution of PM_2.5, i.e. 10 classes. However, the figure that should be taken into greater consideration in this study is Figure 3 which represents the attribution of the exposure class to the residential cohort through the concentration map divided into the four classes of PM_2.5.

11. The format standardization of this manuscript is poor. Authors need to carefully organize the format.

The comment is not clear, we used the standard provided by the journal.

 

We would like to thank the reviewer for his/her constructive comments, which have helped us to enhance the clarity and comprehensibility of the text.

Reviewer 2 Report

Comments and Suggestions for Authors

The publication discusses a retrospective population-based cohort study conducted in the Venafro Valley, Southern Italy, to assess the impact of anthropogenic air pollution, particularly fine particulate matter (PM2.5), on cardiovascular diseases. The study used a multi-stage random forest model to estimate exposure to air pollution from various sources, including industrial facilities, traffic, and biomass combustion.

The research aimed to evaluate the association between PM2.5 exposure and cause-specific mortality and morbidity, focusing on cardiovascular diseases. The study found that the entire cohort was exposed to PM2.5 levels exceeding the World Health Organization's recommended limits, with significant mortality and morbidity excesses observed, particularly for heart diseases and ischemic heart diseases in certain exposure classes. These findings suggest a need for mitigation actions in the region to reduce health risks associated with air pollution.

The study also discusses the mechanisms through which PM2.5 exposure can lead to adverse cardiovascular outcomes, such as oxidative stress, inflammation, and autonomic nervous system stimulation. Despite some limitations, including the challenges of accurately attributing exposure based solely on residential addresses, the study underscores the importance of addressing air pollution as a significant public health issue.

The study presents a novel approach by using a multi-stage random forest model to integrate various data sources, such as particulate matter measurements, satellite observations, land-use patterns, and meteorological information, to estimate exposure to air pollution in the Venafro Valley, Southern Italy. This methodology allows for a more detailed and precise estimation of PM2.5 exposure across different areas within the study domain, contributing to the understanding of the relationship between air pollution and cardiovascular diseases. The study's focus on integrating multiple pollution sources and considering sex-specific risks adds further innovation to the research.

However, the study does acknowledge certain limitations and areas for improvement. One key limitation is the reliance on residential addresses to estimate exposure, which may not fully capture individuals' actual exposure levels due to daily movements and activities outside the home. Additionally, the study did not account for potential confounding factors such as smoking, alcohol consumption, diet, and occupational exposures, which could influence the results. The authors suggest that future studies could refine the methodology by improving exposure assessments, incorporating other analytical investigation methods, and considering individual lifestyle factors to reduce uncertainty and enhance the reliability of the findings.

In conclusion, while the study is innovative in its approach and provides valuable insights, there is room for improvement, particularly in the areas of exposure assessment and the consideration of additional confounding factors.

The text appears to be well-written and professionally structured, with no significant syntactical or grammatical errors. The language is formal and appropriate for a scientific publication. The sentences are clear, and the ideas are well-organized. However, as with any academic writing, there might be minor areas for improvement in terms of flow or style, but these do not constitute grammatical or syntactical errors.

Overall, the text meets the high standards expected in academic writing, particularly in a peer-reviewed scientific article.

The study is thorough and well-executed, covering a comprehensive analysis of the impact of PM2.5 exposure on cardiovascular diseases in the Venafro Valley. It utilizes advanced methodologies, such as the multi-stage random forest model, to assess exposure and analyzes a large cohort over a significant period. The study effectively discusses the results, contextualizes them within existing literature, and highlights the importance of addressing air pollution in the region.

However, the study does acknowledge some limitations and areas that could be considered incomplete. For example, the reliance on residential addresses for exposure assessment may not fully capture actual exposure levels, as it does not account for daily activities and movements outside the home. Additionally, the study did not include certain potential confounding factors like smoking, alcohol consumption, diet, and occupational exposures, which could influence the outcomes. These omissions suggest that while the study is robust, there are areas where additional data or analysis could provide a more complete understanding of the health impacts of air pollution in this region.

In summary, the study is comprehensive, but there are certain areas where further research or additional data could enhance the completeness and accuracy of the findings.

Author Response

Reviewer 2

The publication discusses a retrospective population-based cohort study conducted in the Venafro Valley, Southern Italy, to assess the impact of anthropogenic air pollution, particularly fine particulate matter (PM2.5), on cardiovascular diseases. The study used a multi-stage random forest model to estimate exposure to air pollution from various sources, including industrial facilities, traffic, and biomass combustion.

The research aimed to evaluate the association between PM2.5 exposure and cause-specific mortality and morbidity, focusing on cardiovascular diseases. The study found that the entire cohort was exposed to PM2.5 levels exceeding the World Health Organization's recommended limits, with significant mortality and morbidity excesses observed, particularly for heart diseases and ischemic heart diseases in certain exposure classes. These findings suggest a need for mitigation actions in the region to reduce health risks associated with air pollution.

The study also discusses the mechanisms through which PM2.5 exposure can lead to adverse cardiovascular outcomes, such as oxidative stress, inflammation, and autonomic nervous system stimulation. Despite some limitations, including the challenges of accurately attributing exposure based solely on residential addresses, the study underscores the importance of addressing air pollution as a significant public health issue.

The study presents a novel approach by using a multi-stage random forest model to integrate various data sources, such as particulate matter measurements, satellite observations, land-use patterns, and meteorological information, to estimate exposure to air pollution in the Venafro Valley, Southern Italy. This methodology allows for a more detailed and precise estimation of PM2.5 exposure across different areas within the study domain, contributing to the understanding of the relationship between air pollution and cardiovascular diseases. The study's focus on integrating multiple pollution sources and considering sex-specific risks adds further innovation to the research.

However, the study does acknowledge certain limitations and areas for improvement. One key limitation is the reliance on residential addresses to estimate exposure, which may not fully capture individuals' actual exposure levels due to daily movements and activities outside the home. Additionally, the study did not account for potential confounding factors such as smoking, alcohol consumption, diet, and occupational exposures, which could influence the results. The authors suggest that future studies could refine the methodology by improving exposure assessments, incorporating other analytical investigation methods, and considering individual lifestyle factors to reduce uncertainty and enhance the reliability of the findings.

In conclusion, while the study is innovative in its approach and provides valuable insights, there is room for improvement, particularly in the areas of exposure assessment and the consideration of additional confounding factors.

The text appears to be well-written and professionally structured, with no significant syntactical or grammatical errors. The language is formal and appropriate for a scientific publication. The sentences are clear, and the ideas are well-organized. However, as with any academic writing, there might be minor areas for improvement in terms of flow or style, but these do not constitute grammatical or syntactical errors.

Overall, the text meets the high standards expected in academic writing, particularly in a peer-reviewed scientific article.

The study is thorough and well-executed, covering a comprehensive analysis of the impact of PM2.5 exposure on cardiovascular diseases in the Venafro Valley. It utilizes advanced methodologies, such as the multi-stage random forest model, to assess exposure and analyzes a large cohort over a significant period. The study effectively discusses the results, contextualizes them within existing literature, and highlights the importance of addressing air pollution in the region.

However, the study does acknowledge some limitations and areas that could be considered incomplete. For example, the reliance on residential addresses for exposure assessment may not fully capture actual exposure levels, as it does not account for daily activities and movements outside the home. Additionally, the study did not include certain potential confounding factors like smoking, alcohol consumption, diet, and occupational exposures, which could influence the outcomes. These omissions suggest that while the study is robust, there are areas where additional data or analysis could provide a more complete understanding of the health impacts of air pollution in this region.

In summary, the study is comprehensive, but there are certain areas where further research or additional data could enhance the completeness and accuracy of the findings.

 

We thank the reviewer both for the careful and timely analysis of our work and for having deeply understood the difficulties and complications in conducting this type of study. We agree with the reviewer that the study can be reinforced improving the exposure assessment and considering additional risk factors, such as lifestyle, alcohol consumption and smoking. In rewriting the discussion and conclusions, we have taken the observations into account and highlighted the limitations and strengths of the study.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have revised the manuscript as requested last time.

Comments on the Quality of English Language

Minor editing of English language required.