Heavy Metal Content in Medicinal Plants Grown in Hydroponics and Forest Soil in the Central Part of Western Siberia
, Zoya A. Samoylenko 1, Inessa V. Kravchenko 1, Elena V. Bulatova 1, Natalia M. Gulakova 1, Denis A. Baranenko 1,3 and Yuliya Yu. Petrova 1Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear Authors,
I have reviewed your manuscript entitled “Heavy Metals Content in Medicinal Plants Grown in Hydroponics and Forest Soil in the Central Part of Western Siberia”. The study has some flaws that need to be formally corrected and some technical/scientific questions need to be answered and corrected.
Line133. Specify the material of the containers.
Line140. Indicate the make and model of the lamps
Line225. Hypericum perforatum, should be in italics. Please, also review the names in the Figure 1.
Section: Sampling and soil analysis: The analytical quality assurance used is not indicated. Please indicate whether reference samples or certified standards have been used. Please give reasons for your answer in any case.
Section 3.1. Chemical composition of the soil sample and hydroponic material: Please indicate whether the results refer to dry weight (d.w.) or wet weight since moisture may distort the results. Please give reasons for your answer in any case
Fig1 . It is not indicate if there are significant differences between the different treatments (Hydroponic vs Soil), mark the differences with (*). Differences should be justified from a statistical point of view, by performing an ANOVA test and a post-hoc analysis.
From a human health protection point of view, you should have included in your study (Discussion section) the Tolerable Daily Intake (TDI) for each of the metals studied and discuss whether the concentrations found in each of the species may pose a risk to human health.
Author Response
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Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authorsforests-3157397-peer-review-v1
Heavy Metals Content in Medicinal Plants Grown in Hydroponics and Forest Soil in the Central Part of Western Siberia
The manuscript describes an experimental study about the evaluation of metals contents in selected medicinal/aromatic and berry plants from the forest ecosystem of the city of Surgut, in the central part of Western Siberia. To test the ability to accumulate toxic elements, the plant species (Origanum vulgare, Thymus vulgaris, Hypericum perforatum, Artemisia dracunculus, Rubus arcticus) were collected in the field and grown under hydroponic cultivation, under artificial light. Metals contents (Cd, Cu, Pb and Zn) were determined in soil samples, mineral wool substrate, fertilizers, and the plants grown in different conditions. The results were interpreted in terms of a comparative analysis of metals in the two groups of plants, and regarding the values in the Federal Law of Russia, as well as the recommended by WHO and FAO.
This is a classic simple study, with a simple methodological approach, but adds information to the knowledge about the presence of metals in plants commonly used in medicines and food, and more specifically in the plants from this specific geographical area. So, the study has a local and generalised interest, for researchers, the pharmaceutical industry and local health authorities.
The description of the study and analysis was also kept simple, but explained in a concise and organised manner. However, there are a few aspects that need to be clarified:
- Methods: should be added information on replicates and control samples, repeatability, reproducibility.
- Statistical analysis: although mentioned in section 2.5, no information on statistical analysis is presented. The statistical approach in this type of study is necessary. For example, the ANOVA analysis is applied to determine statistically significant differences between groups
- Discussion: The Rubus arcticus shows a different behaviour, the contents are higher in plants cultivated in hydroponic conditions than in plants collected in the study area. This might be an interesting result. Do the authors have an explanation to this observation? It should be included in the discussion.
Please also correct:
Line 155 - weighted
Line 221 – below respective detection limits
Comments on the Quality of English LanguageQuality of English is fine. The text needs final editing to revise a few sentences which need to be clarified and to correct typos.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsDear Authors you have analyzed Heavy Metals Content in Medicinal Plants Grown in Hydroponics and Forest Soil.
You have done good work, but to my mind, there is one question, that it is obvious that cultivating plants in metal contaminated soils will absorb the metals present in the agro-ecosystem. Further, there are some plant which uptake more metals as compared to others, it depends upon the plant's root system and associated microflora.
Further, under hydroponics conditions, where we maintain controlled environment, including substratum (if used), water and minerals. There if water and minerals are free from any heavy metals, then there is no question of metal absorption by the plants.
At the end of abstract you have mentioned that "This research serves to illustrate the environmental impact of industrial activities and to identify hydroponics as a potential strategy for their mitigation".
Do you really think that hydroponics could be exploited as a potential strategy for their mitigation of heavy metals?? Is cultivating the plants using hydroponics will be cost effective compared to soil cultivation?
Authors are requested to answer these queries at the end of discussion.
Overall, the work is good, abstract is ok, introduction described the background and purpose of work. Materials & methods section described nicely the work done.
Results can be improved.
Discussion part is ok, but the logical justification of hydroponics preference over soil cultivation is needed.
Comments on the Quality of English Language
Dear Editor
The work done is simple but interesting, the manuscript may be considered for publication after satisfactory reply from authors
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsDear authors,
The manuscript has been improved according to my indications. I only make one remark, I think it would be necessary to indicate in the own tables and figures that the values of concentrations are refered to dry weight (d.w.). If not, at least indicate it in the figure caption or table heading as a note. Although this has been included in the text (Line 203), I think it is necessary to indicate it in the figures and tables.
Author Response
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Reviewer 2 Report
Comments and Suggestions for AuthorsRevised version - forests-3157397
The authors have made important changes in this revised version, which improved the manuscript. However, I still have a few doubts that arose when I was reading the text:
- reference to p should be placed after mentioning significative differences between studied plants or treatments. Example: line 241 – significant differences (p<0.005)…; line 248 - …plants grown in hydroponics p<0.015 for hypericum, and p<0.031 for oregano… indication of p must be revised.
- the graphs in Fig. 1 show that the contents of metals are higher in hydroponics treatments, in particular Cu and Zn, but in the text (lines 331-332) the authors state that “However, the concentration of heavy metals is found to be lower than that observed when the plant was cultivated in open soil systems.”. So, as it is written is a contradiction. As well, it is not clear the connection between the fact that the metal contents are higher in Rubus cultivated in hydroponics and the statements in the following sentences. The sentence in lines 337 to 339 is odd?? The text in this paragraph (lines 328-339) needs to be revised and clarified.
Comments on the Quality of English Languageediting
Author Response
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Reviewer 3 Report
Comments and Suggestions for AuthorsDear Authors, you satisfactorily replied to the queries of the reviewers.
Author Response
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Author Response File: Author Response.pdf
