Sustainable Local Food Evaluation by Dosage of Some Metallic Pollutants in Wild Insect Species Consumed in Togo

Round 1

Reviewer 1 Report

Title: Sustainable local food evaluation by monitoring bioaccumulation of some metallic pollutants in wild insect species consumed in Togo

Manuscript ID: sustainability-1567042

Title of the paper:

The title is not clear and it needs to be revised.

Abstract

The abstract needs to be revised, especially, the last three sentences.

Introduction

Changes have been made in the introduction section to be addressed.

Materials and methods

The number of each species collected and used for the analysis should be mentioned in the methods.

Page 4, lines 118-120 should be revised.

Line 122-123; The source of the equation used to calculate the concentration of the metals should be mentioned.

Line 124, check the comment and address it.

Results

The results were poorly presented and it needs revision. The results should also include the spatial differences in metal concentration as the work was down across the whole country.

The species names should be in italics.

Order and Family should start with Uppercase.

Discussion

The discussion section should be elaborated and include other studies on bioaccumulation of metals in insects.

Conclusion

Change MTEs to TMEs

Lines 214-215; The sentence is not clearly supported in the results and discussion.

Comments for author File: Comments.pdf

Author Response

We thank to reviewer for the precious time and invaluable comments. All recommendations were considered. These are summarized below an performed in text (in yellow). 

Title of the paper: The title is not clear and it needs to be revised.

The title table has been revised. 

Abstract: The abstract needs to be revised, especially, the last three sentences. Thank you for your sugestion and the reader's effort. We perform the modifications in text.

Introduction: Changes have been made in the introduction section to be addressed. Thank you for your sugestion.

Materials and methods

• The number of each species collected and used for the analysis should be mentioned in the methods. We perform the modifications in text (Pages 2-3).
• Page 4, lines 118-120 should be revised. Thank you for your sugestion. We perform the modifications.
• Line 122-123; The source of the equation used to calculate the concentration of the metals should be mentioned. Thank you for your sugestion. We performed the addition.

Line 124, check the comment and address it. Thank you for your sugestion. We corrected.

Results

• The results were poorly presented and it needs revision. The results should also include the spatial differences in metal concentration as the work was down across the whole country. Thank you for your sugestion. Please consider that the work was carried out in the country, but the sampling of each species was carried out within the ethnic groups that consume the species. As a result, the sampling of each species was most often done within the same ecological zone. For example, Cybister tripunctatus and Sternocera interrupta were sampled only in ecological zone 1. Gnathocera trivittata, Gnathocera impressa, Gnathocera varians, Rhabdotis sobrina, Pachnoda cordata, Pachnoda marginata were sampled only in ecological zone 2.
• The species names should be in italics. We corrected.
• Order and Family should start with Uppercase. We corrected.

Discussion

• The discussion section should be elaborated and include other studies on bioaccumulation of metals in insects. Thank you for your sugestion. Please consider that are few works on the bioaccumulation of metals in insects. The results of the present work have been compared with those of other insects (Köhler et al.,2020 ; Poma et al. 2017 ; dowu et al. 2013 and Mabossy-Mobouna et al. 2017).

  Conclusion

• Change MTEs to TMEs. We corrected.

  Lines 214-215; The sentence is not clearly supported in the results and discussion. Thank you for your sugestion. We corrected.

Author Response File: Author Response.pdf

Reviewer 2 Report

The study evaluates the level of trace metals (TMEs) accumulation by insect species commonly consumed in Togo. The topic is of scientific and social relevance, as it considers an alternative to change food systems to make them sustainable. The authors adequately substantiated the rationale for the study in the introduction. The objective is clear, as is the expected outcome (to estimate the health risk of insect consumption for the consuming populations).

 

Materials and Methods:

The authors described the study design concerning the territory explored for the collection of samples but did not present the differences among the collection regions. Therefore, it is unclear whether all insects' species were collected monthly or if only one type or group was collected each month at the locations shown in Table 1.

Differentiating between regions and seasons is very important. Possibly, the authors did not find statistical differences in the results and therefore did not present a table with these relationships. However, it would be interesting, even as supplementary material, to make this data available.

Considering that the toxic amount of TMEs is tiny, it would be interesting for the authors to indicate the portion of insects usually consumed by the population and the amount of TME present in this portion.

 

Discussion and conclusions:

The discussion and conclusion are objective and appropriate. References are adequate and up to date about the topic.

Author Response

We thank to reviewer for the precious time and invaluable comments. We have carefully addressed all of the comments. These are summarized below an performed in text (in yellow).

Materials and Methods:

The authors described the study design concerning the territory explored for the collection of samples but did not present the differences among the collection regions. Therefore, it is unclear whether all insects' species were collected monthly or if only one type or group was collected each month at the locations shown in Table 1. 

Thank you for your suggestions. Please consider that the work was carried out in the country, but the sampling of each species was carried out within the ethnic groups that consume the species. As a result, the sampling of each species was most often done within the same ecological zone. For example, Cybister tripunctatus and Sternocera interrupta were sampled only in ecological zone 1. Gnathocera trivittata, Gnathocera impressa, Gnathocera varians, Rhabdotis sobrina, Pachnoda cordata, Pachnoda marginata were sampled only in ecological zone 2.  Also, insects are seasonal. Depending on the species, their period of abundance over the course of a year is highly variable. They were not collected monthly but according to their annual period of abundance.

Differentiating between regions and seasons is very important. Possibly, the authors did not find statistical differences in the results and therefore did not present a table with these relationships. However, it would be interesting, even as supplementary material, to make this data available.

Thank you for your suggestions. Indeed these aspects can offer more informations related to the evaluated zone, but please consider the difficulty to procure data from these poor areas. 

Considering that the toxic amount of TMEs is tiny, it would be interesting for the authors to indicate the portion of insects usually consumed by the population and the amount of TME present in this portion. 

 Thank you for your suggestions. The portion of insects usually consumed by the population varies greatly depending on the species and especially on their period of abundance. This estimate requires further fieldwork. We will consider for other studies. 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Please refer to the comments in the previous section and addressed all of them.

Author Response

We thank to reviewer for the precious time and invaluable comments. All recommendations were considered. The modifications were performed in text and below please find the responses at your recommendations.

The title is not clear and it needs to be revised. The title was been revised: ”Sustainable local food evaluation by dosage of some metallic pollutants in wild insect species consumed in Togo”.

The abstract needs to be revised, especially, the last three sentences. We corrected: « It appears that traces of different metallic elements exist in the samples at variable rates with an excess of the criteria of edibility (0.5 mg/kg) at the level of Cybister tripunctatus for Cadmium (0.504 mg/kg) and Lead (0.501 mg/kg). This aquatic species is the most contaminated. The concentrations of all TMEs in insects during this study are within acceptable limits for human consumption» read « It appears that traces of different metallic elements exist in the samples at variable rates. The aquatic species Cybister tripunctatus is the most contaminated with the level for Cadmium (0.504 mg/kg) and Lead (0.501 mg/kg) at the limit of edibility threshold. The concentrations of all TMEs in insects during this study are within acceptable limits for human consumption».

Changes have been made in the introduction section to be addressed. We thank you very much. 

The number of each species collected and used for the analysis should be mentioned in the methods. We added: The different insect species were not counted but weighed. The number of grams of each species used for the analysis has been specified on Page 3, lines 96 (10 grams).

Page 4, lines 118-120 should be revised. We corrected: «These TMEs are the most sought after in food because they are the most toxic (Be, Cd, Ga, Hg, Pb, Rb and Sr) or the most toxic above a certain threshold (Ag, As, Cr, Co, Cu, Mn, Ni, Se, V and Zn) to living organisms. » read «  These TMEs are the most sought in food because they are the most toxic to living organisms».

Page4, Line 122-123; The source of the equation used to calculate the concentration of the metals should be mentioned. We added: « The real concentrations are determined with the following formula » read «The real concentrations are determined with the following formula (ISO 17294:2003)».

Line 124, check the comment and address it. We revised: «CS is concentration of the spectrophotometer» read « CS is the analyte concentration».

The results were poorly presented and it needs revision. The results should also include the spatial differences in metal concentration as the work was down across the whole country. Thank you for your recommendation. The sampling of each species was carried out within the ethnic groups that consume the species. As a result, the sampling of each species was most often done within the same ecological zone. For example, Cybister tripunctatus and Sternocera interrupta were sampled only in ecological zone 1. Gnathocera trivittata, Gnathocera impressa, Gnathocera varians, Rhabdotis sobrina, Pachnoda cordata, Pachnoda marginata were sampled only in ecological zone 2.

The species names should be in italics. Order and Family should start with Uppercase. We corrected. 

The discussion section should be elaborated and include other studies on bioaccumulation of metals in insects. Thank you for your recommendation. The results of the present work have been compared with those of other insects (Köhler et al.,2020 ; Poma et al. 2017 ; dowu et al. 2013 and Mabossy-Mobouna et al. 2017).

Change MTEs to TMEs. We corrected.

Lines 214-215; The sentence is not clearly supported in the results and discussion. We corrected: The sentence «The levels of Cu, Mg and Zn are statistically higher in 58.33% of the species studied» was removed. 

Author Response File: Author Response.docx