An Analysis of Occupational Hazards Based on the Physical Ergonomics Dimension to Improve the Occupational Health of Agricultural Workers: The Case in Mayo Valley, Mexico

Round 1

Reviewer 1 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

The Authors have satisfactorily improved the quality of the manuscript.

Hence, in this reviewer's opinion it can be considered for publication.

Author Response

Comment 1: The Authors have satisfactorily improved the quality of the manuscript.

Hence, in this reviewer's opinion it can be considered for publication.

Response 1: Thank you so much for your advices.

Author Response File: Author Response.docx

Reviewer 2 Report (Previous Reviewer 2)

Comments and Suggestions for Authors

1.     It is recommended to merge the Introduction and Literature Review sections. The Introduction already includes many elements of a literature review, making it inappropriate to separate them.

2.     It is recommended to move subsection 3.1 to the end of the Methodology section.

3.     This resubmitted version explains the calculation of the sample size, which is crucial for similar studies as it directly affects the validity of the study. Consequently, this study calculated n=197, but the calculation process remains unclear. Was G*Power used for the calculation? Please provide a clearer explanation of the calculation process.

4.     Please move subsections 6.1, 6.2, and 6.3 to the end of the Discussion section.

5.     I understand that at this stage of the research, particularly when the analysis has been completed, many corrections cannot be made. However, based on the study's rationale and logic, I strongly suggest that the authors strengthen the explanation and clarification of the following issues:

(1) The impact of a relatively small sample size.

(2) Line 180 states that the current population (relevant number of employees) is about 500,000. Thus, the results of this study should be generalizable to this population. Given the relatively young age of this study's sample (as noted in Lines 223-230), the authors should indicate the difference between the age of this study's sample and the age of the population.

(3) Previous studies have used the NMQ method, supplemented by logistic regression analysis, to effectively verify the relationship between task factors and physical hazards. However, this study used PCA. The authors should explain the comparison with past research methods or the necessity of using PCA.

Author Response

Comment 1: It is recommended to merge the Introduction and Literature Review sections. The Introduction already includes many elements of a literature review, making it inappropriate to separate them.

Response 1: Our working group analyzed the comment and concluded that the introduction section provides generalities, while the literature review section provides more detail about the research problem and approaches. In fact, recent articles published in the Safety Journal support our comment.

https://www.mdpi.com/2313-576X/10/2/51

Comment 2: It is recommended to move subsection 3.1 to the end of the Methodology section.

Response 2: Our working group analyzed the comment and concluded that changing the location of the subsection does not change the main objective of the Methodology section. Therefore, subsection 3.1 has been moved to the end of the Methodology section (subsection 3.3). We are also changing the references affected by this subsection movement.

Comment 3: This resubmitted version explains the calculation of the sample size, which is crucial for similar studies as it directly affects the validity of the study. Consequently, this study calculated n=197, but the calculation process remains unclear. Was G*Power used for the calculation? Please provide a clearer explanation of the calculation process.

Response 3: The document had an error. The document has been changed based on the reviewer's comment. Please check lines 181-185, “Considering the aforementioned, given a confidence level of 93% (i.e. the degree of certainty that the data are representative of the whole population) and a margin of error of 7% (i.e. the percentage of error that may be present in the sample), the theoretical sample size should be 168 agricultural workers, using the Simple Random Sample method (SRS) in MatLab© program.”

Comment 4:   Please move subsections 6.1, 6.2, and 6.3 to the end of the Discussion section.

Response 4:  Our working group analyzed the comment and concluded that the subsections mentioned were well-placed. In fact, recent articles published in the Safety Journal support our comment.

https://www.mdpi.com/2313-576X/10/3/55

https://www.mdpi.com/2313-576X/10/2/52

Comment 5: I understand that at this stage of the research, particularly when the analysis has been completed, many corrections cannot be made. However, based on the study's rationale and logic, I strongly suggest that the authors strengthen the explanation and clarification of the following issues:

(1) The impact of a relatively small sample size.

(2) Line 180 states that the current population (relevant number of employees) is about 500,000. Thus, the results of this study should be generalizable to this population. Given the relatively young age of this study's sample (as noted in Lines 223-230), the authors should indicate the difference between the age of this study's sample and the age of the population.

(3) Previous studies have used the NMQ method, supplemented by logistic regression analysis, to effectively verify the relationship between task factors and physical hazards. However, this study used PCA. The authors should explain the comparison with past research methods or the necessity of using PCA.

Response 5:

Regarding comment 1, lines 160-165 provide information on the representativeness of the sample, “Considering the aforementioned, given a confidence level of 93% (i.e. the degree of certainty that the data are representative of the whole population) and a margin of error of 7% (i.e. the percentage of error that may be present in the sample), the theoretical sample size should be 168 agricultural workers, using the Simple Random Sample method (SRS) in MatLab© program. In our case, the sample is 200 people, which means it is representative and adequate for the population. In our case, the sample is 200 people, which means it is representative and adequate for the population.” Also in subsection 6.2. Limitations, Line 433-438, our argument is clarified, “Another limitation could be the sample size. Although it was mentioned earlier that the sample size is representative with a confidence level of 93% and a margin of error of 7%, it is possible to improve the accuracy of the results by increasing the confidence level and decreasing the margin of error, e.g. with a confidence level of 95% and a margin of error of 5%, the future sample size should be 384 agricultural workers.”

Concerning comment 2, although it would be interesting to analyze the age distribution of the population, as was done with the sample, according to the Sinaloa Agricultural Census 2022, there is no such detailed public information on this matter.

Regarding comment 3, subsections 3.3. Statistical method and 6.3. Future research, the relevance of the method used (PCA) is already mentioned. Also the need to use other methods to make comparisons. In the case of the NMQ method, the design of this questionnaire has nominal-type responses, whereas the instrument designed for our research has ordinal-type responses. Therefore, we consider that such a specific comparison is not necessary. Furthermore, the variables of the NMQ method are not comparable with the variables of our instrument (see Table 3).

Author Response File: Author Response.docx

Reviewer 3 Report (Previous Reviewer 3)

Comments and Suggestions for Authors

The OHSAS 18001 standard has been repealed , it has been replaced by ISO 45001:2018. Please edit in the article.

Author Response

Comment 1: The OHSAS 18001 standard has been repealed , it has been replaced by ISO 45001:2018. Please edit in the article.

Response 1: The comment is correct. The document was modified to clarify the idea. See Line 77-81, “…Formally, there are occupational health and safety standards and regulations properly established, e.g., ISO 45001 Occupational Health and Safety Management System Requirements, and in the past, OHSAS 18001, Occupational Health and Safety Assessment Serie, and the recommendations of the International Labour Organization, which has been withdrawn and replaced by ISO 45001.”

Author Response File: Author Response.docx

Reviewer 4 Report (Previous Reviewer 4)

Comments and Suggestions for Authors

All comments and suggestions were responded to satisfactorily by the authors.

Article quality has been significantly improved.

Author Response

Comment 1: All comments and suggestions were responded to satisfactorily by the authors. Article quality has been significantly improved.

Response 1: Thank you so much for your advices.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report (Previous Reviewer 2)

Comments and Suggestions for Authors

I appreciate the authors for their diligent efforts in revising the manuscript. Their careful and detailed revisions are evident. I have thoroughly reviewed the authors' responses to my previous questions and concerns, and I found that all of them have been well addressed, whether through revision or clarification. However, some issues that cannot be changed in this stage have also been considered as the study limitations. I am pleased to say that I have no further comments on the revised manuscript.

Reviewer 3 Report (Previous Reviewer 3)

Comments and Suggestions for Authors

Comments have been incorporated.

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

Comments and Suggestions for Authors

The manuscript proposes an interesting study on physical ergonomics occupational risks among farmers by means of the Principal Component Analysis (PCA) method.

The manuscript is well organised and the subject fits well with the journal topics.

However, before considering it for publication, several improvements are needed.

First, in the introduction, the research motivations are too vague and need to be elaborated more. In addition, in this section, a background analysis is needed to present the state of the art in the investigated field. This is of paramount importance to justify the research in a scientifically sound manner. For this purpose, studies addressing ergonomics issues among farmers should be mentioned to underline the relevance of the subject and research gaps. For example, you can consider the following research on physical ergonomics improvement in the use of work equipment: https://doi.org/10.3390/agriengineering5010015; https://www.designsociety.org/download-publication/32030/A+REVERSE+ENGINEERING+APPROACH+TO+ENHANCE+MACHINERY+DESIGN+FOR+SAFETY.

In section 2, additional information on the research approach should be provided, for example including a diagram/flowchart that illustrates the different steps of the analysis. Moreover, the questionnaire used for the survey could be included as an annex. The criteria used to define the nine variables related to physical ergonomics should be explained as well. The use of both the KMO and Bartlett's tests should be described and justified in this section.

In section 3 the use of diagrams illustrating the output of the analyses could be beneficial for the reader.

The discussion of results needs to be augmented to better highlight the merits of the study taking into account the extant literature.

Text proofreading is needed to improve the quality of language and correct some typos (e.g. lines 118-119; line 154).

In conclusion, the strength of the study relies on the ergonomics analysis carried out, which can certainly augment knowledge among ohs among farmers.

The weakness of the study is related to the lack of a scientifically sound approach both in defining the research motivations and discussing the research outputs.

Comments on the Quality of English Language

Text proofreading is needed to improve the language quality and correct typos.

Reviewer 2 Report

Comments and Suggestions for Authors

This study investigated the health and safety concerns of agricultural workers in a specific region of Mexico. While the manuscript provides valuable insights, its overall writing quality requires further enhancement. Issues such as the small sample size, unclear delineation of working characteristics, lack of clarity regarding whether the sampled respondents are representative of the broader population, the methods of analysis employed, and the comparison of results all impact the study contribution.

On line 15, the use of a sample of 200 individuals, segregated by gender and age groups, and analyzed using a closed Likert scale survey with five response levels, suggests a relatively small sample size. Guidance on determining an adequate sample size should be included in the Methods section.

Line 18 states findings regarding perceived occupational risks, which align with previous research, potentially limiting the novelty of the study's contribution. Referencing prior work by Keyserling (2000) could support this observation. [Keyserling, W.M. (2000). Workplace risk factors and occupational musculoskeletal disorders, part 1: a review of biomechanical and psychophysical research on risk factors associated with low-back pain. American Industrial Hygiene Association Journal, 61, 39-50.]

Line 63 contains a statement regarding psychophysical demands that lacks clarity. Rephrasing is needed to accurately convey the authors' intended meaning.

Lines 46-59 discuss ergonomic concepts common in occupational safety and health, which could be better structured within the Introduction section to provide a clearer progression from general concepts to specific research objectives and contributions.

Regarding Figure 1 on line 19, the discrepancy between the surveyed location and the photograph's location should be rectified by replacing the image with one taken in the Mayo Valley, Mexico.

On line 100, the use of Principal Component Analysis (PCA) should be justified, as it may not address cause-and-effect relationships. Clear rationale for employing PCA over other statistical methods is necessary.

Lines 100-122 should focus on detailing the specific methods used in the study and why they were chosen over alternative approaches.

Table 1 and Table 2 (lines 123 and 124) are criticized for conveying minimal information and could potentially be replaced with explanatory text.

Lines 129-131 raise concerns about the representativeness of the sample and its alignment with the demographic characteristics of the Mayo Valley or Mexico.

Line 132 highlights the need for a clearer description of the workers' specific tasks to facilitate generalization of the study findings.

Regarding Table 3 (line 141), justification for the inclusion of the nine questions related to physical ergonomics in the survey is needed, along with evidence of their validity from previous studies.

The use of a closed Likert scale survey with five response levels should be briefly explained in the survey process (line 143).

On line 154, the absence of a Discussion section is noted, which should include comparisons with past research findings.

Line 172 suggests correcting the presentation of significance values as <0.001 instead of Significance= 0.000.

Finally, on line 265, the study limitations should be more comprehensively addressed.

Reviewer 3 Report

Comments and Suggestions for Authors

The article has an exploratory character without significant scientific contribution. The authors performed statistics on the effect of ergonomic factors on a sample of people in the agricultural industry. In the introduction, they state that the standards and legislations of safety and health at work are not correctly established. I allow myself to disagree, because the area of health and safety is covered very completely by legislation and regulations. There are various international ISO standards in the field of occupational health and safety and machinery safety. It is difficult to determine the ergonomic factors of the working environment in a field where working conditions are constantly changing. There are now various freely available tools for the prediction of musculoskeletal disorders under just such loads.

There is a lack of elaboration of the available legislative and regulatory requirements in our country and in the world. There is also a lack of development of available tools for the identification of ergonomic factors and their prediction.

Reviewer 4 Report

Comments and Suggestions for Authors

The subject under study is current and relevant, particularly because it is a very important sector in a country's economy.

The abstract needs to be revised because it is very confusing and the aim of the study and its relevance are not well understood. The following topics can be used as a reference: Introduction (contextualizing the study and its relevance); objective of the work; methodology used; results (main results obtained); conclusion (main contributions to the state of the art and current practice) and future studies.

The article needs to be reorganized because the information is presented in a confusing way, for example the authors mix up materials and methods with results.

In the introduction, the authors should present and characterize the problem that has been studied, where this problem occurs or exists, and what its relevance is.

In the Introduction, the concepts of Ergonomics are presented in a very confusing way and not all the statements are entirely correct. For example, according to the International Ergonomics Association, Ergonomics has 3 dimensions, physical, cognitive and organizational, but the authors have added a fourth, environmental, without even understanding what it consists of or what theoretical support it has. This part needs to be reviewed and supported by reference literature. The authors claim that there are no studies on the occupational health of agricultural workers, but if they had carried out a search on Scopus they would have realized that this does not correspond to reality. In fact, there are also several studies on physical ergonomics in this activity.

The authors do not present a theoretical framework to support the study. In addition, the bibliographical references used are very dated (only 5 references out of 21 have been published in the last 5 years) and do not reflect the state of the art.

The authors don't explain on which type of farm the data was collected, as agricultural crops have specific characteristics that condition the type of tasks and the conditions in which they are carried out. The tasks that were analysed need to be described, as well as whether there are any specific characteristics of the workers.

The authors do not explain how the sample was selected, nor what the inclusion and exclusion criteria were. The questionnaire that was supposedly applied is not presented, nor how it was developed and validated. The way in which the questionnaire was validated and applied is also very important, particularly in a sample with low levels of education and training.

The methodology is presented in a very summary and generic way, which does not allow for a full understanding of the way in which the data was collected and the possibility of replicating the study.

The authors present a statistical treatment of the data, but it is not possible to analyse it because it is not possible to understand what they were analysing.