Workers’ Occupational Dust Exposure and Pulmonary Function Assessment: Cross-Sectional Study in China

Round 1

Reviewer 1 Report

Dear authors, your work is enjoyable to read.

I would have minor aspects to add to your manuscript presentation.

Please see the file in the attachment

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The authors conducted quite interesting statistical studies from a scientific point of view on the impact of occupational dust on workers and the assessment of lung function in the context of the People's Republic of China. The data provided are up-to-date and new. However, there are some comments on this manuscript:

1. It is necessary to issue an abstract in accordance with the requirements of the journal;

2. Table captions should be centered. It is necessary to check and fix;

3. Table 2, in my opinion, needs to be reworked to fit the format of a "book" page;

4. It is necessary to concretize the conclusions, give specific measures that will prevent dust occurrence and exposure to dust, specify certain numerical intervals of maximum permissible concentrations of dust and its effect on the studied population;

5. It is necessary to issue a reference in accordance with the requirements of the journal, in particular, to give an abbreviated name to the journals, to italicize them, to remove the dates. It is necessary to arrange it as required by the rules of registration for this journal, which are given in the section "Guidelines for authors".

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

This is manuscript presents data from highly relevant preventive work. The manuscript is not acceptable in it's present form but have great potential. I think it should merit publication after some important improvement and clarifications. 

Major 

1) this is a transectional study.  You cannot talk about incidens ( cases per time unit) change to prevalence

2) in abstract you use the wording " abnormal rate of pulmonary function. I would use the  other wording for example " Increased prevalence of abnormal pulmonary function

3) Line 68 There are research questioning the etiological role of smoking  smoking for pneumoconisosis. "Jacobsen M, Burns J, Attfield MD. Smoking and coalworkers' simple pneumoconiosis. Inhaled Particles. 1975 Sep;4 Pt 2:759-772. PMID: 1236248." Smoking is however imprtant for pulmonary functions especially FEV1 and ther ratio FEV1/FVC. Yous hsould perhaps calrify this difference.

I furthermore recommend that data of smoking fore example Packyears shoudl be collected monitoring workers in the future

4) line 88 more information regarding the reseons for not being part of the final analysis should be given preferably as a flow chart 2045/5483

5) lines 104-110. I was not aware of the regulations regarding particles treshold limit values in China. This needs more explanation Especially if it should be used as criteria for abnormal exposure different from normal. Measurements in exhaled air? I have never encountered that do you hve more information explaining the reasons for using that?

6) line 115 Please ad criterias used for defining  "pneumoconiosis-like changes." There are for example ILO criteria

7) Table 1

Chi-2 test only give information that the categories are not of similar prevalence. It is ok to present in this way but ione shoudl be cautious with the interpretation. Cement dus seem to be worse than quartz dus not ok

dust categoreis a dominated by silica dust. I would recommend that  the authors do a sub analysis just for that category if you want to illustrate the effect of other factors given i table 1. A restricted analysis would even more important for the multipleregression part. It is difficult to interpret data when you put different types of dusts as a common  exposure factor.

8) Line 138 check language The abnormal rate of FEV1, FVC, and FEV1/FVC was 4.25% (87/2045), 12.81% 138 (262/2045), and 1.47% (30/2045), respectively. Expain the used defintions of abnormal rate. 

9) Table 2 Lung fucntion se 8) above. One could consider using GLI reference values and lower limit of normal according to ATS/ERS. And more importatntly how do you define abnormal/ normal dust exposure?

Table 2 clearly indicate that effects are mostly related to silica dust. Thsi should be the focus for the Multivariate Logistic Analysis

TAble 3 you should not limit the presentation to only significant data. 

More important dust exposure abnormal seem to be protective för an effect on FVC but a risk factor for FEV1/FVC. This indicates that the effect my be more of obstructive character.  I recommend that you discuss this finding in more detail classical silicosis are described as a rare restrictive but you find an effect that might be related to the much more common COPD disease that are an important effect from inorganics dust exposure>/ quarz.

Would i be possible to create a slighltly better exposure measure for example Exposure time* Concentration? If yes then you could perhaps se even clerarer results in your model (you should probably only include those that have silica dust exposure see pont 9 above. This is realted to your comment on lines 185-187. The reasons for no effect is probably due to misclassification in the exposure variable so pleas try to develop this a little further.

 

 

Minor 1) Table 1 and 2 Categories for age and exposure time are expressed in an inexact way could age middel category be expressed as 40 > - ≤ 50

And in a corresponding way för exposure time

2) Table 3 better but first catagorys should probably read < rather than ≤

 

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

I am fine with the sponses changes