Managemental Impacts on Particulate Matter Emission in Tunnel-Ventilated Broiler Houses

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors presented an interesting research on the concentration of the fine dust and aerosols inside the poultry house to investigate the exposure risk of the workers. The research idea is sound and the manuscript is well structured and written. Experimental data from production condition were also collected and can throw light on further work to control the dust concentration inside poultry house.

Some comments to the authors: It is a good idea to separate the working conditions into two categories, ie, MWP and SWP. Perhaps in production condition the lasting time of MWP or SWP can also strongly impact the dust concentration. Some discussion should be added into the manuscript.

Author Response

Response to Reviewer 1 Comments

 

We deeply appreciate your precious reviewed in this manuscript, thus we can improve this research article. Based on the feedback you provided, I have revised the main text and made efforts to improve the English sentences throughout. Minor corrections (such as typos and diagram numbers) have been made in the manuscript without indicator in red.

 

The authors presented interesting research on the concentration of the fine dust and aerosols inside the poultry house to investigate the exposure risk of the workers. The research idea is sound and the manuscript is well structured and written. Experimental data from production condition were also collected and can throw light on further work to control the dust concentration inside poultry house.

Comment 1) Some comments to the authors: It is a good idea to separate the working conditions into two categories, ie, MWP and SWP. Perhaps in production condition the lasting time of MWP or SWP can also strongly impact the dust concentration. Some discussion should be added into the manuscript.

 

Response) Line 211-224

In the analysis of PM exposure levels, time is an important consideration. In this study, we analyzed particle size-specific concentrations using real-time monitoring results obtained by aerosol spectrometer. Real-time measurements of PM concentrations were taken at 6-seconds interval, and based on the results of particle size analysis and video analysis, we differentiated between the dynamic work period(DWP), when workers were moving for management purposes, and the static work period(SWP), when they remained stationary position for mainte-nance purposes. To reduce data errors, we calculated the concentration of the remaining data, excluding the front and back 10% of data for each of the two periods, as the concen-tration for that work period.

The average duration of the moving period was 3.04±1.63 minutes, while the working period lasted 2.27±1.12 minutes. To enhance data stability and remove outliers, we deleted the front and back 10% of data from both DWP and SWP in 6-second interval real-time data, and then calculated the average to obtain a single dataset. Statistical analysis was conducted to ascertain if there were significant differences in concentrations between DWP and SWP according to particle sizes.

Reviewer 2 Report

Comments and Suggestions for Authors

The work reports the results of measurements of particulate matter and aerosol in five poultry farms. The topic is interesting and the equipment used for assessing the particulate concentration is based both on passive and active samplers. However, the work has several limitations and the manuscript should be improved significantly.

The main concern regards the methodology used.

It seems that the measurements are carried out for just one day in five different farms. Two farms have been monitored in autumn and three in summer. Thus, the measurements of the different farms cannot be compared as they are different. The daily variability is an important factor that has not been considered. The lack of repetition does not allow any comparison.

Moreover, the external concentration of particulate has not been measured.

In general, the terminology is not uniform.

I think that the definition of Active and passive sampler should be reported. In my opinion, the use of an active pump to collect the particulate matter in a filter is not a passive sampler.

The authors use the two terms aerosol and particulate matter as synonyms. I think it might be better to distinguish the two terms as part of particulates can settle and are then resuspended when birds or workers move. This dust should not be included in aerosol.

The results presentation can be improved. The data of concentrations in the single farms is not reported. The comparison of the measures obtained with the two methods is not reported.

 

Introduction

Line 52-63 – This section is rather academic and should be incorporated in the previous part of the introduction, just explaining the main aspects.

Line 77-78 I was expecting a decrease in activity with the age. How can you explain this increase?

The introduction might be more focused on the health effect and limits indicated by different organizations in the world.

Besides that, it would be interesting an overview of other experiences in monitoring particulate in poultry farms.

Materials and methods

The description of the 5 building should be improved. The dimensions of the buildings are important.

It seems that JA-1 is significantly smaller than the others. The ventilation system should be detailed (type of fan, flow-rates).

 

Line 187 – It is reported that: During the experiment conducted in the summer season, the sidewall inlets were completely closed. Why the usual ventilation system has been altered?

Report the days of measurement (not ony the season).

What about external concentrations of particulates?

Line 242-244 – It is not clear how the classification has been done. When the workers stop, there is the need of some time to allow the settling of particles. How this has been managed?

Results

Line 254-257 – this sentence can be deleted as already reported in methods.

Line 258-262 – The ventilation flow rates in the different farms should be reported.

Line 264 – Figure 5 should be Figure 6

Line 308-309 – Figure 6. I think this figure is misleading. If I well understood the summer is the average of three different farms while autumn is the average of two different farms. As the farms are different, with different characteristics and monitored in different days, they should be treated separately, without aggregating the data. The meaning of the bars should be clarified.

Line 274-275 - This statement is not supported by the results as the farms are different and there are not information on the concentrations in the same farm in the two seasons. The differences among farms are also stated by the authors at line 279 and following “There were variations in absolute concentrations measured between farms,  primarily due to differences in farm management practices………..”

Line 289-291 – It not clear. Clarify to what parameter the percentage are referred.

Line 293 – PM2.5 should be smaller than 2.5 µm

Line 325-326 – Figure 7. See the comments to figure 6. Why error bars are not reported here?

Line 332-340 – Move this paragraph to methods

Line 355-356 – Figure 8. It would be nice to compare these data with those obtained with the gravimetric filters. There bars are not defined, but there is a high variability. What’s the cause?

Line 363-368 – This considerations cannot be valid as the farms are different.

Line 387-389 – the statistical analysis should be reported in methods. It is not clear what has been compared: the workers?

Conclusions

The first part of the conclusions is a summary and is not what is expected.

Line 426-430 – This conclusions are not supported by the results and are not motivated

Punctuation, typing errors etc. should be checked carefully

Author Response

Response to Reviewer 2 Comments

 

We deeply appreciate your precious reviewed in this manuscript, thus we can improve this research article. Based on the feedback you provided, I have revised the main text and made efforts to improve the English sentences throughout. Minor corrections (such as typos and diagram numbers) have been made in the manuscript without indicator in red.

 

The work reports the results of measurements of particulate matter and aerosol in five poultry farms. The topic is interesting and the equipment used for assessing the particulate concentration is based both on passive and active samplers. However, the work has several limitations and the manuscript should be improved significantly.

The main concern regards the methodology used.

Comment 1) It seems that the measurements are carried out for just one day in five different farms. Two farms have been monitored in autumn and three in summer. Thus, the measurements of the different farms cannot be compared as they are different. The daily variability is an important factor that has not been considered. The lack of repetition does not allow any comparison.

Moreover, the external concentration of particulate has not been measured.

Response 1)

To maximize generalizability for commercial poultry farms, experiments were conducted aligning with the farm size and ventilation structures. Given that the concentration of fine dust varies significantly based on external weather conditions and internal operational practices, standardizing these factors for experimentation proved to be exceedingly challenging. Moreover, extrapolating exposure to fine dust for agricultural workers based on results obtained from a specific individual farm is difficult. Therefore, efforts were made to collect data from a diverse range of farms. While constraints in time and budget prevented measurement on a larger scale, we were able to adequately indicate the approximate levels of exposure and highlight that workers are exposed to higher concentrations during their movement, despite the inability to measure more farms. Weather data and external particulate matter concentration data for all experiment dates have been added.

 

Comment 2) general, the terminology is not uniform.

Response 2) The entire text was revised taking terminology into consideration.

 

Comment 3) I think that the definition of Active and passive sampler should be reported. In my opinion, the use of an active pump to collect the particulate matter in a filter is not a passive sampler.

Response 3) Line 46-55 – As you pointed out, I incorrectly wrote the concepts of passive and active samplers, so I have revised the text accordingly. The methods used were all active, and I have removed the content distinguishing between passive and active.

Instead, I have explained that the Local monitoring used the gravimetric method, and the Personal monitoring used the light scattering method. Furthermore, I have revised all the relevant content throughout the text.

 

Comment 4) The authors use the two terms aerosol and particulate matter as synonyms. I think it might be better to distinguish the two terms as part of particulates can settle and are then resuspended when birds or workers move. This dust should not be included in aerosol.

Response 4) The terms aerosol, dust, and particulate matter were frequently interchanged. While semantically, PM is the most accurate, for the sake of simplicity in explanation, the term "Dust" has been included. Throughout the text, efforts were made to minimize the use of "Aerosol," and certain essential sections originally based on PM were adjusted to incorporate the term "Dust."

 

Comment 5) The results presentation can be improved. The data of concentrations in the single farms is not reported. The comparison of the measures obtained with the two methods is not reported.

Response 5) Line 276-277

In response to your feedback, the text has been thoroughly revised, encompassing both the method and results of the experiment. Additionally, farm-level data has been incorporated.

 

 

Introduction

Comment 6) Line 52-63 – This section is rather academic and should be incorporated in the previous part of the introduction, just explaining the main aspects.

Response 6) I have deleted the entire section as it was considered non-essential to the overall flow, consisting of textbook-like explanations.

 

Comment 7) Line 77-78 I was expecting a decrease in activity with the age. How can you explain this increase?

Response 7) In this context, 'age' refers to the activity of chicks and adult chickens. For accurate conveyance of the meaning, I have removed the part concerning 'age' and supplemented the description focusing on the movement of chickens.

 

Comment 8) The introduction might be more focused on the health effect and limits indicated by different organizations in the world.

Besides that, it would be interesting an overview of other experiences in monitoring particulate in poultry farms.

Response 8) Line 31-86

Following your comments, the introduction part has been revised entirely.

 

Materials and methods

Comment 9) The description of the 5 building should be improved. The dimensions of the buildings are important.

It seems that JA-1 is significantly smaller than the others. The ventilation system should be detailed (type of fan, flow-rates).

Response 9) Line 112 – Five broiler houses with the same ventilation structure were selected from commercial farms in Korea. Due to the scarcity of land suitable for poultry farming in Korea's geographical landscape, it was challenging to find broiler houses of identical size and structure as those in flat areas. Therefore, through a large poultry processing company (Harim inc.), farms with the same ventilation structure and system were recruited. JA-1, despite its smaller size and fewer ventilation fans, implemented the same system. Relevant information has been added to the text.

 

Comment 10) Line 187 – It is reported that: During the experiment conducted in the summer season, the sidewall inlets were completely closed. Why the usual ventilation system has been altered?

Report the days of measurement (not only the season).

What about external concentrations of particulates?

Response 10) Line – 108-112, 165

In Korea, the temperature difference between winter and summer can reach over 50 degrees Celsius. Sidewall inlets are used only during the coldest months to provide minimal ventilation, while tunnel ventilation using end exhausting fans is employed during the changing and summer seasons. I have made revisions to the sentences to enhance clarity and comprehension.

Following your comments, we have provided detailed information on the measurement dates and external particle concentrations in Table 1&2."

 

Comment 11) Line 242-244 – It is not clear how the classification has been done. When the workers stop, there is the need of some time to allow the settling of particles. How this has been managed?

Response 11) Line 211-217

As mentioned in the comment, stabilization takes time, but this study focused on monitoring the particulate matter (PM) in the air breathed by workers, both during moving and staying. Additional explanations regarding DWP (dynamic work period) and SWP (Static work period) have been added.

 

Results

Comment 12) Line 254-257 – this sentence can be deleted as already reported in methods.

Response 12) The sentence was deleted as following your comment

 

Comment 13) Line 258-262 – The ventilation flow rates in the different farms should be reported.

Response 13) Line 112, 231-235

The ventilation rates for each farm have been added to Table 1, and explanations regarding these ventilation rates have been included in the relevant sections of the text.

The ventilation rates varied according to the size of the experimental commercial broiler houses, with an average of 12.0 CMH/head (cubic meters per hour) during the summer, and 2.1 CMH/head during the transitional seasons.

 

Comment 14) Line 264 – Figure 5 should be Figure 6

Response 14) fully followed your comment

 

Comment 15) Line 308-309 – Figure 6. I think this figure is misleading. If I well understood the summer is the average of three different farms while autumn is the average of two different farms. As the farms are different, with different characteristics and monitored in different days, they should be treated separately, without aggregating the data. The meaning of the bars should be clarified.

Response 15) Line 253-274

In the overall context, the sections pertaining to summer and autumn were revised and supplemented, focusing on ventilation rates for each farm. Additionally, all data related to the farms were re-presented and modified by Figure 6, and the explanation for it was enhanced.

 

Comment 16) Line 274-275 - This statement is not supported by the results as the farms are different and there are not information on the concentrations in the same farm in the two seasons. The differences among farms are also stated by the authors at line 279 and following “There were variations in absolute concentrations measured between farms, primarily due to differences in farm management practices………..”

Response 16) Line 253-259

Following your comment, the relevant section has been rewritten. Due to the experimental results not encompassing a broader range of farms, as noted in your comment, it is difficult to generalize the findings. Since the farms are not identical, it's challenging to analyze the results seasonally. Therefore, the results have been presented in terms of differences in ventilation rates by season, and the relevant paragraph has been rewritten in this perspective.

 

Comment 17) Line 289-291 – It not clear. Clarify to what parameter the percentage are referred.

Response 17) Line 260-266

Following your comment, the relevant section has been rewritten.

The findings were presented in the context of exceeding the particulate matter exposure standards for workers as outlined by Donham et al. (2000), and additional explanations were provided to supplement this information.

 

Comment 18) Line 293 – PM2.5 should be smaller than 2.5 µm

Response 18) Line 265-271

Fully followed your comment.

Considering that field measurements captured PM-2.5, whereas respirable dust has a size of 2.5 µm or smaller, it is reasonable to assume that the actual exposure of farm workers to respirable dust may be higher than indicated by the measurements.

 

Comment 19) Line 325-326 – Figure 7. See the comments to figure 6. Why error bars are not reported here?

Response 19) Line 253-274

In this paper, Figure 7 was deemed not crucial to the explanation and was therefore removed. Especially since Figure 6, which was rewritten using all the data, could encompass the necessary details from Figure 7. Consequently, the figure was deleted, and the accompanying explanation was enhanced.

 

Comment 20) Line 332-340 – Move this paragraph to methods

Response 20) Line 211-217

Fully followed your recommendation

Real-time measurements of PM concentrations were taken at 6-seconds interval, and based on the results of particle size analysis and video analysis, we differentiated between the dynamic work period(DWP), when workers were moving for management purposes, and the static work period(SWP), when they remained stationary position for maintenance purposes. To reduce data errors, we calculated the concentration of the remaining data, excluding the front and back 10% of data for each of the two periods, as the concentration for that work period. 

 

Comment 21) Line 355-356 – Figure 8. It would be nice to compare these data with those obtained with the gravimetric filters. There bars are not defined, but there is a high variability. What’s the cause?

Response 21) Line 294-295

The figure displays data measured and differentiated into DWP (Dynamic Work Period) and SWP (Static Work Period) based on real-time data monitored for particle size using an aerosol spectrometer. Due to the use of real-time data, there were instances where a large amount of PM temporarily clustered near the intake even though we tried to minimize that effect, leading to high deviations in the data values. Each data point represents an average of about 2-5 minutes, and the error bars indicate the standard deviation of the measured results.

Additionally, to facilitate comparison with data obtained using the gravimetric method, which involves monitoring using filters, this data was also presented.

 

Comment 22) Line 363-368 – This considerations cannot be valid as the farms are different.

Response 22) Line 299-309

Fully following your comments, similar to previous comments, the generalizations made in the text were altered to interpret the data farm-by-farm, based on ventilation rates and the relevant sections of the manuscript were modified.

 

Comment 23) Line 387-389 – the statistical analysis should be reported in methods. It is not clear what has been compared: the workers?

Response 23) Line 221-224, 327-329

Statistical analysis was conducted as a means to ascertain if there were significant differences in concentrations between DWP and SWP. As shown in Table 3, TSP and PM-10 exhibited a strong correlation, PM-2.5 showed a weak correlation, and PM-1.0 demonstrated no significant difference. Explanations regarding the analysis have been added to the Methods section, and the results have been further supplemented and presented accordingly.

 

Conclusions

Comment 24) The first part of the conclusions is a summary and is not what is expected.

Line 426-430 – This conclusions are not supported by the results and are not motivated

Punctuation, typing errors etc. should be checked carefully

Response 24) Line 344-360

Based on the comments on the conclusion parts and revisions made to the main text, the entire Conclusion section has been rewritten.

 

Reviewer 3 Report

Comments and Suggestions for Authors

Manuscript agriculture-2644796 entitled “Particulate matter exposure in forced ventilated broiler house based on working conditions”. Please notice the following:

General view: The manuscript highlighted a great point of view and emphasized the particulate matter emission in broiler farms concerning working activity and their negative influence on the workers. Copyediting and proofreading of the manuscript as well as a necessity to update the references should be carried out to enhance readability and understanding and to achieve the publication value.

Title: Non-expressive and preferred to be modified into “Managemental Impacts on Particulate Matter Emission in Tunnel-ventilated Broiler Houses”.

Abstract: Clear to a greater extent.

Keywords: Prefered to rearrange in alphabetical order.

Introduction: The introduction is properly arranged and displayed into three long paragraphs that have to be more concise and informative.

The aim: Clear to a greater extent.

Materials and methods: Please notice the following:

1.      Provide further details on the microclimatic conditions that might in an indirect way influence the birds’ activity and the PM emission in the five commercial broiler farms such as microclimatic temperature, relative humidity, housing system & design, manure management, drainage system, lighting program, bird-proof measures, rodent-proof measures, cleaning and disinfection procedures, and treatment and vaccination during the experiment if any.

2.      No ethical statement or approval number was listed.

3.      Specify the sampling number per farm and the total sample size.

4.      Provide a statistical analysis section illustrating the software used, a reference, and the statistical model of the analysis.

Results: Reduce the illustration of numbers among the text of the results as long they are listed in the tables and figures and instead express them in your own words.

Discussion: Informative, clear, and contributes to knowledge with moderate comparison and speculation.

Conclusion: Must be more concise. Remove the first paragraph which was listed with no need.

Authors’ contributions: NA.

Funding: NA.

Acknowledgment: Informative.

References: MUST BE UPDATED  as only 22.5% (7 out of 31) were published in the past five years. The percentage has to increase to at least 35-40%. Old and lack of reference updates negatively impact the importance of the manuscript and show that the study is no longer a point of interest.

Tables: Well organized and presented.

Figures: Well organized and presented.

Comments on the Quality of English Language

Language: The manuscript was expressed using moderate language and grammar.

Author Response

Response to Reviewer 3 Comments

 

We deeply appreciate your precious reviewed in this manuscript, thus we can improve this research article. Based on the feedback you provided, I have revised the main text and made efforts to improve the English sentences throughout. Minor corrections (such as typos and diagram numbers) have been made in the manuscript without indicator in red.

 

Manuscript agriculture-2644796 entitled “Particulate matter exposure in forced ventilated broiler house based on working conditions”. Please notice the following:

General view: The manuscript highlighted a great point of view and emphasized the particulate matter emission in broiler farms concerning working activity and their negative influence on the workers. Copyediting and proofreading of the manuscript as well as a necessity to update the references should be carried out to enhance readability and understanding and to achieve the publication value.

Response 1) We have made efforts to improve the overall manuscripts following reviewer’s recommendation.

 

Title: Non-expressive and preferred to be modified into “Managemental Impacts on Particulate Matter Emission in Tunnel-ventilated Broiler Houses”.

Particulate matter emission in tunnel-ventilated broiler houses based on working conditions

Response 2) Line 2-3 – We fully followed your recommendation.

 

Comment3) Clear to a greater extent. ; Keywords : Preferred to rearrange in alphabetical order.

Response 3) Line 28-29 – We fully followed your recommendation.

 

Response 4) Introduction: The introduction is properly arranged and displayed into three long paragraphs that have to be more concise and informative.(The aim:Clear to a greater extent.)

Response 4) Line 31-85 – We fully followed your recommendation. I have summarized the key content concisely to provide logical information.

 

Materials and methods: Please notice the following:

Comment 5) Provide further details on the microclimatic conditions that might in an indirect way influence the birds’ activity and the PM emission in the five commercial broiler farms such as microclimatic temperature, relative humidity, housing system & design, manure management, drainage system, lighting program, bird-proof measures, rodent-proof measures, cleaning and disinfection procedures, and treatment and vaccination during the experiment if any.

Response 5) Line 95-108, 112

In this study, commercial farms were visited when the broilers were four weeks old, and monitoring focused primarily on the concentration of particulate matter during the barn work. Additional field data related to the generation of particulate matter were included in the text. The farms' management systems uniformly applied a tunnel-type forced ventilation system. The vaccination and biosecurity levels were consistent across all farms, which were considered excellent controlled by large distribution company for chickens. They followed an all-in, all-out procedure, where after the broilers were shipped out, thorough cleaning was conducted, and all litter was replaced.

 

Comment 6) No ethical statement or approval number was listed.

Response 6) As this study does not involve experimentation on animals, it was determined that it does not fall under the ethical statement and approval number mentioned.

 

Comment 7) Specify the sampling number per farm and the total sample size.

Response 7) The gravimetric method was conducted continuously for 6 hours at four locations: the inlet, center, exhaust, and outside the farm. Real-time particulate matter concentrations, measured using an aerosol spectrometer, were recorded at 6-second intervals, specifically during periods when workers entered and exited throughout the entire monitoring duration. Detailed information regarding the sampling process is provided in the main text using Tables 1 and 2.4.Provide a statistical analysis section illustrating the software used, a reference, and the statistical model of the analysis.

Response 8) Line 221-224

Statistical analysis was conducted to ascertain if there were significant differences in concentrations between DWP and SWP according to particle sizes. The collected data were analyzed by SPSS 22.0 program using descriptive statistics, independent samples t-test was performed.

Results: Reduce the illustration of numbers among the text of the results as long they are listed in the tables and figures and instead express them in your own words.

Response 9) Line 228-342

The entire results section has been revised, with providing a detailed discussion of the results following your comments.

 

Discussion: Informative, clear, and contributes to knowledge with moderate comparison and speculation.

Response 10) Based on the valuable opinions of reviewers, many parts of the text were revised and improved. The entire text was revised and supplemented to supplement the discussion in the results section.

Conclusion: Must be more concise. Remove the first paragraph which was listed with no need.

Response 11) Fully followed your comments, and the content of the text has been completely rewritten.

Authors’ contributions: NA.

Funding: NA.

Acknowledgment: Informative.

Comment 12) References: MUST BE UPDATED as only 22.5% (7 out of 31) were published in the past five years. The percentage has to increase to at least 35-40%. Old and lack of reference updates negatively impact the importance of the manuscript and show that the study is no longer a point of interest.

Response 12) To enhance the percentage of papers published within the last 5 years from the current 7 out of 31 to 17 out of 41, accounting for 41.5%, additional review and supplementation of the latest papers were undertaken.

9. Wang, K.; Shen, D.; Dai, P.; Li, C. Particulate matter in poultry house on poultry respiratory disease: A systematic review. Poultry Science 2023, 102556, doi:10.1016/j.psj.2023.102556.
10. Yang, W.; Guo, M.; Liu, G.; Yu, G.; Wang, P.; Wang, H.; Chai, T. Detection and analysis of fine particulate matter and microbial aerosol in chicken houses in Shandong Province, China. Poultry science 2018, 97, 995-1005, doi:10.3382/ps/pex388.
11. Yasmeen, R.; Ali, Z.; Tyrrel, S.; Nasir, Z.A. Assessment of respiratory problems in workers associated with intensive poultry facilities in Pakistan. Safety and health at work 2020, 11, 118-124, doi:10.1016/j.shaw.2019.12.011.
12. Younis, F.; Salem, E.; Salem, E. Respiratory health disorders associated with occupational exposure to bioaerosols among workers in poultry breeding farms. Environmental Science and Pollution Research 2020, 27, 19869-19876, doi:10.1007/s11356-020-08485-x.
13. Zhou, Y.; Xu, B.; Wang, L.; Zhang, C.; Li, S. Fine Particulate Matter Perturbs the Pulmonary Microbiota in Broiler Chickens. Animals 2023, 13, 2862, doi:10.3390/ani13182862.
14. Li, Z.; Xiong, Y.; Wang, S.; Wang, C.; Ji, B.; Liu, Y.; Liang, C.; Tong, Q. Assessing particulate matter concentration level and its limit exceedance based on year-round field measurements of different laying hen building systems. Biosystems Engineering 2023, 226, 266-279, doi:https://doi.org/10.1016/j.biosystemseng.2023.01.014.
15. dos Anjos Magri, C.; Garofallo Garcia, R.; Binotto, E.; Duarte da Silva Lima, N.; de Alencar Nääs, I.; Sgavioli, S.; de Castro Burbarelli, M.F. Occupational risk factors in health of broiler-farm workers: A systematic review. Archives of Environmental & Occupational Health 2021, 76, 482-493, doi:10.1080/19338244.2020.1832036.
16. Kim, K.Y. Distribution of concentration and emission of dust according to types of poultry buildings in Korea. 2017, doi:https://doi.org/10.5668/JEHS.2017.43.3.185.
17. Seo, H.-J.; Oh, B.-W.; Kim, H.-C.; Sin, S.-J.; Seo, I.-H. Concentrations of particulate matter exposed to farm workers in the broiler houses. Journal of The Korean Society of Agricultural Engineers 2020, 62, 27-37, doi:https://doi.org/10.5389/KSAE.2020.62.5.027.
18. Shin, S.-J.; Song, E.-S.; Kim, J.-W.; Lee, J.-H.; Gautam, R.; Kim, H.-J.; Kim, Y.-G.; Cho, A.-R.; Yang, S.-J.; Acharya, M. Major environmental characteristics of swine husbandry that affect exposure to dust and airborne endotoxins. Journal of Toxicology and Environmental Health, Part A 2019, 82, 233-243, doi:https://doi.org/10.1080/15287394.2019.1584596.
19. Lee, B-J; S-S Park. Evaluation of PM10 and PM2.5 concentrations from online light scattering dust monitors using gravimetric and beta-ray absorption methods. Journal of Korean Society for Atmospheric Environment 2019, 35, 357-369, doi:https://doi.org/10.5572/kosae.2019.35.3.357.
20. Choi, S-I; J-A An; Y-M Jo. Review of analysis principle of fine dust. Korean Industrial Chemistry News 2018, 21, 16-23.
21. Yasmeen, R.; Ali, Z.; Tyrrel, S.; Nasir, Z.A. Estimation of particulate matter and gaseous concentrations using low-cost sensors from broiler houses. Environmental monitoring and assessment 2019, 191, 1-10, doi:10.1007/s10661-019-7582-1.
22. Fernández, A.P.; Demmers, T.G.; Tong, Q.; Youssef, A.; Norton, T.; Vranken, E.; Berckmans, D. Real-time modelling of indoor particulate matter concentration in poultry houses using broiler activity and ventilation rate. Biosystems Engineering 2019, 187, 214-225, doi:https://doi.org/10.1016/j.biosystemseng.2019.09.004.
23. Dai, P.; Shen, D.; Tang, Q.; Huang, K.; Li, C. PM2. 5 from a broiler breeding production system: The characteristics and microbial community analysis. Environmental Pollution 2020, 256, 113368, doi:10.1016/j.envpol.2019.113368.
24. Kabelitz, T.; Biniasch, O.; Ammon, C.; Nübel, U.; Thiel, N.; Janke, D.; Swaminathan, S.; Funk, R.; Münch, S.; Rösler, U. Particulate matter emissions during field application of poultry manure-The influence of moisture content and treatment. Science of the Total Environment 2021, 780, 146652, doi:10.1016/j.scitotenv.2021.146652.
25. Shen, D.; Wu, S.; Dai, P.; Li, Y.; Li, C. Distribution of particulate matter and ammonia and physicochemical properties of fine particulate matter in a layer house. Poultry science 2018, 97, 4137-4149, doi:https://doi.org/10.3382/ps/pey285.

 

 

Tables: Well organized and presented.

Figures: Well organized and presented.

 

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I appreciate the effort of the authors in improving the manuscript, but I still think there are major limitations.

The lack of repetitions is the more relevant. The high variability of the measurements evidence the need of more data to obtain results that can be compared effectively.

The comparison of DWP and SWP considering together different farms which very different ventilation systems and size is not correct.

Figure 7 show that considering individual farm the differences between DWP and SWP are not significant as the variability is higher than the differences.

There is still some confusion in terms. TSP are the total suspended particles and not the respirable fraction.

The dust exposure standards used are just one of the possible values and different sources are not discussed.

The comparison with other papers is not adequately performed.