Glyphosate Effects on Earthworms: Active Ingredients vs. Commercial Herbicides at Different Temperature and Soil Organic Matter Levels

Round 1

Reviewer 1 Report

Authors -- Congrats for undertaking a complex and rigorous analysis of an area in dire need of improved science. First, some general comments.

1. The value of this paper arises only partially from the empirical results. A broader array of readers will benefit from the update of ecoloical.eco-tox risk assessment policy and methods, and problems, as so clearly evident in the case of the most heavily used pesticide in history (by a wide margin). As you know, there is enough GLY applied annually to spray ~2/3 of a kg/hectare on every cultivated/harvested hectare on the planet. So, if there are ANY impacts on soil micro communities, earthworms, plant health etc, that impact may be manifest on a large portion of the globe's cropland.

2. Critical, pressing coformulant issues are touched upon in your paper, but warrant more emphasis. There is very little knowledge/testing done  re eco-impacts and public health impacts of GBH herbicides AS APPLIED. The paper cites some low number of eco studies with GBHs -- 17 or 19. That is ridiculous. No one sprays GLY herbicide; no one or ecosystem is exposed to just GLY. And now, most GBHs are being applied with 1 or 2 other active ingredients, and multiple so-called inerts. The eco and health impacts of these very complex mixtures is almost entirely ignored by regulators, and marks the most consequential problem with pesticide law/regs/risk assessment globally. Your paper makes the point well, but please drive it home more forcefully. And say something about GBH+dicamba and GBH+2,4-D.

3. Need to state clearly that "inerts" are rarely "inert," and laws/regs MUST change soon to disclose all ingredients and concentrations, if scientists and public health professionals are to have a chance of sorting out what products are causing which impacts. Remember, way over 50% of all herbicides globally are now being applied in tank mixes with at least 1 other actrive, and multiple inerts. The fact that regulators basically assume a complex mixture will be "safe" if they have deemed each of the ingredients in it, one at a time, "safe" is just madness.

4. Very interesting info re the APG "inert." However, the EFSA reference formulation is Roundup BioFlow with a quartnerary ammonium surfactant. Please discuss this a bit, and also poojnt out in intro, discussion, and conclusion that most of the world, other than the EU, is still applying high-risk POEA-based GBHs.

Specific Comments

P 1., line 22, you use word inert; suggest you put it in quotation marks to alert reader you will have more to say re "inerts"

P. 1, line 29. "...stimulation of the co-formulant APG." is awkward. Suggest reword to something like "...due to the impact of the coformulant APG on worm..."

P. 2, line 46 -- introduce broader discussion of why inerts are not inert.

P. 2, line 47, suggest replace "substances" with "coformulants"

P. 2, line 65, suggest change to "..soils and serve as surrogate..."

P. 2 line 71. Use of term "great" is inappropriate. If there is something unique/unusual re this meta-analysis, state it.

P. 2, lines 77-80. This is where you should state POEA-based GBHs were banned and phased out in the EU in the 2015-2017 period. Good to cite the final order calling for the change. Also explain EFSA picjs  "reference formulation" and why. If you have any data/idea for % total GBH kgs applied that use quartnerary ammonium vs APG as the primary surfactant, that would be VERY IMPORTANT new information. Even if your team can only make an educated guess, that would be better than no info. This is important for MANY reasons.

P. 3, lines 123-126. Suggest you point out/stress 2 things. These OM levels are high relative to much of the arable cropland worldwide, AND the difference is v ery significant (i.e ~40% higher). Readers would benefit from a little more general discussion of the fate of GBHs in soils with OM>3% compared to soils wityh OM<1.5%.

P. 5, line 184, fix "ist"

P. 8, lines 293 and 294 -- I am baffled by what "po" stands for. The "po" in po-potassium salt??

P. 9, line 315. Re APG, I suggest you look up and see if APG is among the "safer" surgactants listed by the US EPA in its compendium of "safer" chemicals. There is a subsection in this list covering "Surfactants." Since little is known re APG, please provide a bit more info on it if you can.

P. 9, line 330-333. You write "...(consisting of different coformulants),..." but said earlier both the GBHs you tested included APG. Also important to again stress that no GBH sold in the EU could contain a POEA-based surfactant after 2017, which is why the Roundup brands sold in the EU post-2017 diod not contain POEA.

P. 9, lines 334-337. Para is hard to follow; please edit and make clearer the points you are making.

P. 10, lines 341-348. Do you think compaction plays a role in explaining your results?

P. 10, line 352. Delete extra "contaminated". Line 367 delete comma.

P. 11, section of effects of coformulants. Important section, should be expanded some. First, throughout, be more precise in the use of the word "toxic". Ideally, mention the assay system/type of impact (e.g. genotoxic response, triggered oxidative stress, reduced capacity to repair damage to DNA). Toxicity is too broad of a term alone to be useful. Second, multiple studies and MON data show that POEAs are about 4-X more acutely toxic than GLY -- but this does NOT account the impacts of POEAs on GBHs toxicity to earthworms or people. Please explain that MON has been trying to convince regualtors for 30 years that any risks from Roundup is caused just by the toxicity of the POEAs alone. Not true. POEAs alter environmental fate; they accelrate movement of the GLY in a GBH through the epidermis of weeds and human skin; they move the GLY in GBHs through cell walls, where the GLY comes into contact with mitochondria and DNA inside cells. And manufacturers have known all the above for decades and done everything they can to keep the scientific community in the dark, and regulators, with great success.

P. 11, line 420. Another phrase needs reworking -- "...more endocrine damaging..."

P. 11, line 425. Suggest replace "well" with "readily". Lines 430-431, delete all author names after Pochon et al. Line 432, you forgot the "not" between do and report.

P. 12, line 472. "its" not "is"

P. 12, lines 476-479. Good place to drive home that current EFSA and US EPA eco-impact testing is basically BS. And that real studies have to be done not just with formulated products, but mixtures of all AIs applied, all "inerts", tank mixes, AND the fertilizers applied to really understand what is going on. The widely accepted fiction that the companies and regulators understand the soil health and ecosystem impacts of contemporary pesticide use patterns is simply BS and needs to be called out for what it is, myths to make it cheaper and easier for pesticide manufacturers to get their products on the market and keep them there, years or even decades after science has caught wind of the harm they are doing.

 

 

 

 

 

 

 

 

 

 

 

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

This is very important work. It is good that you undertake it. The article is well-written and will provide essential background information for the scientific teams working on the assessment of the toxicity of glyphosate.

Author Response

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Reviewer 3 Report

Agrochemicals (ISSN 2813-3145) -MDPI

MS No.: agrochemicals-2072348

Manuscript Title: "Glyphosate effects on earthworms: active ingredients vs. commercial herbicides at different temperature and soil organic matter levels"

Reviewer comments:

In this current study, the authors studied Glyphosate effects on earthworms: active ingredients vs. commercial herbicides at different temperature and soil organic matter levels. The topic fits well with the scope of Agrochemicals, and the results are clear and interesting to the scientific community. However, the text needs a minor revision before publication.

 

Please find my comments in the attached file 

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx