Psychological stress and associated factors among municipal solid waste collectors in Hanoi, Vietnam: A cross-sectional study

Quynh Thuy Nguyen; Bang Van Nguyen; Ha Thi Thu Do; Bich Ngoc Nguyen; Van Thanh Nguyen; Son Thai Vu; Thuy Thi Thu Tran

doi:10.1371/journal.pone.0254355

Peer Review History

Original SubmissionOctober 7, 2020
4 May 2021 Decision Letter - Harald Gündel, Editor PONE-D-20-31502 Psychological stress and associated factors among municipal solid waste collectors in Hanoi, Vietnam: A cross-sectional study PLOS ONE Dear Dr. Bang, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.(please see below). Please submit your revised manuscript by 5/30/2021. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. 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We will update your Data Availability statement to reflect the information you provide in your cover letter. 5. We note you have included a table to which you do not refer in the text of your manuscript. Please ensure that you refer to Table 1 in your text; if accepted, production will need this reference to link the reader to the Table. Additional Editor Comments: Dear Bang, I´m sorry for the delay, but major difficulties to find reviewers as well as current Covid - related consequences (additional clinical and other work) played a role. Best, Harald Gündel [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: This study showed the prevalence of psychological stress and related factors among waste collectors in Hanoi. The data was very valuable and the analytic process was appropriate. I pointed out some concerns to be considered. Major comments. 1.[Materials and methods] The section of "Study area" is not appropriate here. Making the section shorter and inserting it into LN 83 seems suitable. Shorter information is enough to explain the settings and context. 2. [Materials and methods] Authors conducted the structured interview. How many researchers engaged in it? Was there any protocol on how to conduct it? How did you standardize the interview? 3. Please separate Results and Discussion. 4. [Conclusion] The implication for further study might be valuable for potential readers. Minor comments. 1.[Abstract] Please state the scale authors used (DASS-21) in the methods section. 2.[Abstract] Authors use a variety of words to indicate the outcome (eg. "mental stress" "self-reported psychological stress" "stress symptoms"). Please unify them into the same term. 3. (LN 128) Why is there missing data on critical variables by conducting the interview? 4. [Methods] Did the participant receive any reward? 5. (LN176) The work-shift variable is needed to add more information. It is a very important variable. The response option "Yes" is included partial shift? Or, indicates only the everyday shift. 6. [discussion] Can knowledge about occupational safety, protective equipment use, and safety education influence the findings? 7. [discussion] Can interview cause any bias? (eg, Social-desirability bias) ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: Yes:** Natsu Sasaki [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0254355.r001
Revision 1
29 May 2021 Author Response RESPONSE TO REVIEWER’S COMMENTS: Reviewer #1: This study showed the prevalence of psychological stress and related factors among waste collectors in Hanoi. The data was very valuable and the analytic process was appropriate. I pointed out some concerns to be considered. Major comments. 1.[Materials and methods] The section of "Study area" is not appropriate here. Making the section shorter and inserting it into LN 83 seems suitable. Shorter information is enough to explain the settings and context. RESPONSE: - The information on study area (Hanoi city) was moved to the end of Introduction and shortened accordingly as follow: “Similar to other countries in the world, a metropolis like Hanoi, the capital of Vietnam, also faces the challenge of sustainable MSW management [3, 15, 16]. Rapid urbanization, lifestyle changes, and high population density in the city generate an enormous amount of MSW every day, which is collected manually by WCs [17]. Since 2018, the population of Hanoi has increased to over 7.5 million people and the population density to 2.239 people/km2 [18]; its residents resided in 30 district-level administrative units, towns, 584 communes, wards, and towns [19]. Hanoi is located in the tropical monsoon region; hence, the climate is divided into four distinct seasons throughout the year. Temperatures can reach 40°C in summer and below 5°C in winter [20]. According to the Hanoi Department of Natural Resources and Environment, in 2019, about 6,500 tons of domestic MSW was generated daily, of which the MSW of 12 urban districts and Son Tay town accounted for 53.9%, with a 99-100% collection rate. MSW in 17 suburban districts was less than half of the daily amount, but only 87 to 88% were appropriately collected for disposal [15]. The laborious workload, coupled with harsh working conditions such as extreme heat in the summer and low temperatures in the winter, in association with lack of mechanical support for heavy manual work, leads WCs to become physically and mentally exhausted. However, evidence regarding the risk of mental distress among WCs worldwide and particularly in Vietnam is limited. Therefore, this study aimed to examine the prevalence of psychological stress and related factors among WCs in Hanoi, Vietnam. Results from this study will contribute to evidence-based solutions for improving the well-being of WCs in Vietnam and countries with similar MSW systems.” 2. [Materials and methods] Authors conducted the structured interview. How many researchers engaged in it? Was there any protocol on how to conduct it? How did you standardize the interview? RESPONSE: - Additional information had been provided in the Data collection section as follow: “Ten individuals, including researchers and graduate students with experience in conducting structured interviews, collected the data. They were trained thoroughly by the principal investigator on how to conduct the interview, and each practiced on five WCs who belonged to another waste collection company and did not participate in this survey. The principal investigator regularly monitored and supervised the interviewers’ performance and progress directly on the WCs’ worksite.” 3. Please separate Results and Discussion. RESPONSE: - Results and Discussion sections had been separated 4. [Conclusion] The implication for further study might be valuable for potential readers. RESPONSE: - Implication for further study had been provided at the end of conclusion as follow: “Future studies should continue the investigation of mental health among the broader population of WCs from different companies to provide more representative evidence on WCs’ mental health and related factors in Vietnam.” Minor comments. 1.[Abstract] Please state the scale authors used (DASS-21) in the methods section. RESPONSE: - The name of the scale DASS 21 had been put in the abstract 2.[Abstract] Authors use a variety of words to indicate the outcome (eg. "mental stress" "self-reported psychological stress" "stress symptoms"). Please unify them into the same term. RESPONSE: - The term psychological stress was used. 3. (LN 128) Why is there missing data on critical variables by conducting the interview? RESPONSE: � The participants refused to answer even after the interviewer explained details. This sentence was revised as follow: “Fifteen questionnaires were removed because participants refused to provide information on critical variables. The final sample used for the analysis was 802 WCs (response rate of 89.7%).” 4. [Methods] Did the participant receive any reward? RESPONSE: - Additional information was provided at the end of the Data collection section as follow: “After the interview, participants received an herbal tea box as compensation for their participation regardless of their answers. The tea box was worth less than one USD.” 5. (LN176) The work-shift variable is needed to add more information. It is a very important variable. The response option "Yes" is included partial shift? Or, indicates only the everyday shift. RESPONSE: - Additional information was provided in the Measure section as follow: “Work conditions were described in terms of two groups of variables: work organization and exposure to occupational hazards. Work organization variables included the number of work hours per shift (≤ 8 versus 9-12 hours/shift) and work-shift during the last three months (Night shift, from 6 p.m. to 2 a.m., Others [including WCs working the day shift from 5 a.m. to 12 a.m., or the afternoon shift from 1 p.m. to 8 p.m.], or Frequently changed shifts during the last three months).” 6. [discussion] Can knowledge about occupational safety, protective equipment use, and safety education influence the findings? RESPONSE: - This information was included in the discussion as follow: “Having a higher education level also promotes health literacy among WCs, resulting in their better adherence to protective equipment use and attention to occupational services provided by the company such as occupational health and safety education. Hence, WCs with higher education levels might have better health awareness and take better care of their health, including mental health.” 7. [discussion] Can interview cause any bias? (eg, Social-desirability bias) RESPONSE: - This information was included in the limitation section as follow: “First, interviews regarding psychological stress and work conditions could have a degree of bias because of limitations on WCs’ recall ability and awareness of the study topic, or social-desirability bias because of the interviewer’s presence” Attachments Attachment Submitted filename: Response to reviewre.docx https://doi.org/10.1371/journal.pone.0254355.r002
28 Jun 2021 Decision Letter - Harald Gündel, Editor Psychological stress and associated factors among municipal solid waste collectors in Hanoi, Vietnam: A cross-sectional study PONE-D-20-31502R1 Dear Dr. Bang Van Nguyen, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Harald Gündel Academic Editor PLOS ONE Additional Editor Comments (optional): Thanks for this careful response to issues raised by reviewer #1. https://doi.org/10.1371/journal.pone.0254355.r003
Formally Accepted
1 Jul 2021 Acceptance Letter - Harald Gündel, Editor PONE-D-20-31502R1 Psychological stress and associated factors among municipal solid waste collectors in Hanoi, Vietnam: A cross-sectional study Dear Dr. Nguyen: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Harald Gündel Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0254355.r004

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