Environmental Fate of Metal Nanoparticles in Estuarine Environments
Round 1
Reviewer 1 Report
This manuscript presented the review of current status of nanoparticle release into the estuarine and coastal environments and their impacts on marine biota. The topic addressed in this review is of scientific interest due to the increase in the application of nanomaterials in various fields. While the authors prepared a comprehensive review covering all aspects, I feel that this manuscript needs moderate editing for the errors in the text. The full details for some of the abbreviations used in the text is missing. The citation of references in the text also not according to the journal guidelines. The authors provided three figures from other sources, but that is not enough. Try to add table/figure for the impacts of NPs on marine biota. Also a flow chart indicating the biological effects of NPs may add more clarity to the data presented in the text.
Author Response
- The full details for some of the abbreviations used in the text is missing
We provided full detail of the abbreviations, lines 68-69;.85-86.
- The citation of references in the text also not according to the journal guidelines.
We amended the text regarding the format of the citations, deleting the name of the authors and leaving only the numbers.
- Try to add table/figure for the impacts of NPs on marine biota
We do think that Figure 3 represents a good picture of the biological, toxicological, and physiological effects of ENMs. It is preferable to avoid duplication.
Reviewer 2 Report
Major comments:
Major comments
- The authors should revise citations in the text using only numbers. Furthermore, it seems that ‘Cheng et al., 2004’ (Lines 56, 53) has no number of citation. Better to check all the text and the reference list
- Is it possible to add a table listing the main marine organisms affected by NP pollution with appropriate citation?
Minor comments:
- Line 720 ‘physiologioal effects..’ change to ‘physiological..’
- Line 412 ‘In sea nanoparticles rarely are nano sized’- style, please, change the sentence
- Line 334 ‘Xu [2018 29] report how…’ change to ‘Line 334 ‘Xu [29] reports …’
- Lines 628-630: ‘Some marine organisms of coastal waters can be used as monitor of the presence of nanoparticles… Matranga and Corsi [2012 107] proposed the use of model organism and molecular approaches to evaluate the ecotoxicological impact of ENMs on marine environment.’- please enumerate the organisms suitable for NP ecological monitoring before giving a detailed description
Author Response
Major comments
- The authors should revise citations in the text using only numbers. Furthermore, it seems that ‘Cheng et al., 2004’ (Lines 56, 53) has no number of citations. Better to check all the text and the reference list.
As also indicate for reviewer 1, we modified citations in the text indicating only numbers. We also deleted the reference Cheng et al. 2004, since it is not reported in the reference list.
- Is it possible to add a table listing the main marine organisms affected by NP pollution with appropriate citation?
We do prefere to indicate in the text along with the specific section toxicity, bioaccumulation the main organisms affected by NPs exposure.
Minor comments:
- Line 720 ‘physiologioal effects..’ change to ‘physiological.
The text was amended, line 723
- Line 412 ‘In sea nanoparticles rarely are nano sized’- style, please, change the sentence
The sentence was changed: In sea environment NPs are rarely of nano size dimension.
- Line 334 ‘Xu [2018 29] report how…’ change to ‘Line 334 ‘Xu [29] reports …’
The text was amended. Line 336
- Lines 628-630: ‘Some marine organisms of coastal waters can be used as monitor of the presence of nanoparticles… Matranga and Corsi [2012 107] proposed the use of model organism and molecular approaches to evaluate the ecotoxicological impact of ENMs on marine environment.’- please enumerate the organisms suitable for NP ecological monitoring before giving a detailed description
The sentence Matranga and Corsi….environment was postponed, see lines 635-637.
Reviewer 3 Report
In this study, author discussed the environmental fate of metal nanoparticles in Estuarine environments. Little is known about their potential transference into the food web and toxicity features and co-stressors of single or multiple ENMs under laboratory and natural environmental conditions for various taxonomic phyla. The review reports current knowledge on the ecological impact of ENMs under the complex environmental conditions of estuary systems, identifies gaps in current knowledge, and provides the direction for future research.
Although the topic is very relevant, the manuscript is written poorly and needs serious English editing. Also, I found some plagiarized stuff in it. Please clean it.
Manuscript is plagiarized at L35-L39, L123-124, L130-132, L135-138, L141-142, L152-153, L160-161, L170-172, L179-180, L187-193, L219-222, L223-226, L228-232, L236-238, L239-240, L241-243, L245-246, L248, L507, L508-509, L538-539, L559-562, L564-565, L574-575, L650-653, L678-680. Please clean it.
Author Response
- Although the topic is very relevant, the manuscript is written poorly and needs serious English editing. Also, I found some plagiarized stuff in it. Please clean it.
The text was checked and improved for the English.
- Manuscript is plagiarized at L35-L39, L123-124, L130-132, L135-138, L141-142, L152-153, L160-161, L170-172, L179-180, L187-193, L219-222, L223-226, L228-232, L236-238, L239-240, L241-243, L245-246, L248, L507, L508-509, L538-539, L559-562, L564-565, L574-575, L650-653, L678-680. Please clean it.
The phrases:
L 35-L39 was amended as: Based on the production levels, ENMs are ordered in the following descending order [Project on Emerging Nanotechnologies,: titanium dioxide (nTiO2), silicon dioxide (nSiO2), iron (nFe) and iron oxide (nFexOy), zinc oxide (nZnO), silver (nAg), carbon nanotubes (CNTs), cerium oxide (nCeO2), and copper (nCu) and copper oxide (nCuO), metal sulphides, selenides, and tellurides [4, 5,Callaghan and MacCormack, 2017 6; Williams et al., 2019 7].
L123-L124 was amended as: Some authors made a conservative estimates of 4 kg of TiO2 nanoparticles to the water from a touristic Mediterranean beach reveal during a summer day[Sánchez-Quiles and Tovar-Sánchez, 2014 [37].
L130-132 was amended as: Solar radiation may photoexcite TiO2 NPs from UV filters producing significant amounts of hydrogen peroxide (H2O2) and generating stress on marine phytoplankton [Sánchez-Quiles and Tovar-Sánchez, 2014 [37].
L135-138 was amended as: The use of synthetic silica, SiO2 ENMs, goes back to the middle of the last century. Recently, SiO2 ENMs production has significantly increased for mass applications such as tires [Sun et al. 2014 40].
L141-142 was amended as: Nanosilver, Ag ENM, was employed in medical field since the beginning of the last century due to its antibacterial properties [Johnson, 2015 44, 45].
L152-153 was amended as: The use of ZnO NPs may exceed that of TiO2 NPs since these naoparticles can absorb UV-A and UV-B radiation while TiO2 NPs only UV-B, offering better protection and improved opaqueness [Wong et al., 2010 49].
L160-161 was amended as: There are data from Callaghan and MacCormack [2017 6] reporting levels of ENMs in wastewater treatment plants effluent from 10−4 to > 101 μg/L.
L170-172 was amended as: Another source of TiO2 in urban runoff comes from the large use of exterior paints [Coatingsworld, 2019 54].
L179-180 was amended as: There is an objective difficulty discriminating natural from engineered TiO2 in all kind of environmental matrices, especially wnen they are present at high concentration [Adamiec, 2017 56; Wang et al., 2020 57].
L187-193 was amended as: In the case of TiO2 NPs, a good indicator for discrinating natural or anthropic sources is the ratio Ti/Nb. This because natural TiO2 NPs are carriers of Nb in rocks [Loosli et al., 2019 50). Wang et al. [2020 57] quantified this ratio in real urban runoff, two bridges in Columbia, and Ballona Creek and Los Angeles River, USA to reveal the presence of TiO2 engineered particles. They observed in urban runoff an increases in the elemental ratios Ti/Nb respect to natural background values indicating Ti contamination.
L219-222 was amended as: The regulation of ENMs and risk estimation is possible with a clear comprehension of the production and release of these emerging contaminants.
L223-226 was amended as: There are estimations that at least 25% of sunscreens is washed off during bathing and swimming [Danovaro et al., 2008 64], meaning that around 250 tonnes of these NPs can be discharged into the marine environment.
L228-232 was amended as: Models of exposure of existing or new ENMs in combination with toxicological data can contribute to a prospective risk assessment [Hischier et al. 2015 65].
L236-238 was amended as: To date, the quantification of ENMs in environmental samples, especially in solid samples such as soil and sediment, is not possible [Gottschialk et al., 2013 66] and cannot be directly detectable by analytic methods due to their very low concentration. Even if detected, it is difficult to discriminate naturally and engineered nanomaterials[Mueller and Nowack, 2004 67].
L239-240 was amended as: Among ENMs and in terms of release, Ag-ENM is again the most studied nanomaterial so far [Caballero-Guzman 2015 69].
L241-243 was amended as: A valid tool to make environmental risk analysis, is to to model predicted environmental concentrations, PEC, [Gottschalk et al., 2013 66] on the basis of existing environmental levels of ENMs
L245-246 was amended as: Sun et al. [2016 70] used a stochastic approach to predicta CeO2 ENMs in freshwater and reported a range of 1 pg/L in 2017 to a few hundred ng/l in 2050.
L248 was amended as: see the above previous amendment.
L507 was amended as: Mussels are filter feeder organisms and hence represent ideal selective sentinel for probing the environmental fate of ENMs and can bioconcentrate significant levels of NPs [Ward and Kach, 2009 141, 142].
L508-509 was amended as: see the above previous amendment.
L538-539 was amended as: Different toxicity effects were observed by McCarthy et al. [2013 139] in the oyster Crassostrea virginica exposed to ionic silver, cellular damage in gills, and nano silver particles hepatopancreas function damage.
L559-562 was amended as: The higher toxicity of the ionic form respect to the bound metal in NPs was reported by Sendra et al. [2018 151]. The authors tested the toxicological response of the unicellular microalgae Chlorella autotrophica, possessing a typical cellulosic cell wall, and Dunaniella salina, lacking a cell wall, to Ag and CeO2 NPs
L564-565 was amended as: Being at the bottom of the food web marine phytoplankton, as microalgae, , are sensitive to NPs with effects on reproduction, and metabolic functions [Sendra et al., 2018 151].
L574-575 was amended as: What emerges from the literature survey is that an important role is also given by the kind of exposed organism. Hanna et al. [2013 152] exposed for 10 d the amphipod Leptocherius plumulosus to CuO NPs and ZnO NPs. Authors highlighted that while for ZnO NPs the main drive of toxicity was found to be dissolution, for CuO NPs toxicity did not depend on metal dissolution [Hanna et al., 2013 152]. The polychaete worm Nereodes diversicolor exposed to CuO NPs generated accumulation of Cu and production of ROS and highlighted a different uptake route between NPs and ionic metal.
L650-653 was amended as: Literature [Barhoumi and Dewez, 2013 165] studied the hypersaline unicellular green algae Dunaliella salina as a pollution indicator in marine ecosystem of ENMs. This because the algae possesses an elevated rate of bioaccumulation and sensitivity.
L678-680 was amended as: The former regards the up regulation of the phase II antioxidant enzymes, as is the case of catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase and transferase.
Round 2
Reviewer 1 Report
This manuscript is improved greatly from the last version. The authors response is satisfactory.
Reviewer 3 Report
I am happy with the author's comments and believe that the manuscript can be accepted in its current form.
