ToxicMisleading the Mislead
A recent article on AgMag BLOG[1] points fingers at EPA for not protecting us from Monsanto’s herbicide Roundup™.  It claims that a recent scientific article (on-line Feb 17, 2016) shows that EPA is falling short in its duty to protect Americans from the dangers of glyphosate, the active ingredient in Roundup™.  This is the herbicide that we have use as a weed killer at home and on the farm for almost 45 years.  The blog then gives an opinion that Big Ag groups defend glyphosate in a knee-jerk response because the weed killer is necessary for the world food supply and they need to maintain business as usual, no matter how destructive the product is to human health and the environment.


The blog is misleading on both points.  The original scientific article[2] is a consensus statement by some leading environmental health and herbicide experts, expressing concerns on the over use of glyphosates and the resulting exposures.  The article doesn’t even mention EPA in the Abstract and less than 20 times in the following 7700 words of text.  The paper does point out that 1) glyphosate use has dramatically increased, 2) initial risk evaluation was deemed low because it inhibited a key plant enzyme pathway that is found only in plants, fungi and some bacteria, but not mammals, 3) scientific evidence is accumulating that some vertebrate pathways may be a target, and 4) human exposure is clearly increasing.  Taken together, the authors recommend a fresh and independent examination of glyphosate toxicity.


Nowhere in the scientific article do they indicate that EPA is not protecting us from glyphosate toxicity or that Monsanto needs a wakeup call in their business related to human health and the environment.  In fact, the article reports that the herbicide was first assessed in 1970 (brought to market 1974) and the regulatory agencies (eg, EPA) found minimal mammalian toxicity.  When the herbicide was re-registered in 2009, the EPA identified a number of issues and data gaps.  EPA required the registrants to conduct both neurotoxicity and immunotoxicity studies, currently a standard request.  EPA’s updated risk assessment and final re-registration decision on glyphosates is soon scheduled to be completed (2016).  Is this not a health protective action?


The original scientific article may be misleading as well.  The authors present in the first part of the article glyphosate’s history, increasing usage/exposure, and its presence in foods but build a circumstantial case for risk concerns (actually a series of recommendations), using words such as: associated with, suggest associations, sometimes, implicated, likelihood, may alter, may be linked, suggest, possible, may interfere, might, likely, potentially, may incur, and nearly certain.  There were findings, but these were not causally linked to glyphosate toxicity. It certainly makes a case that we do not know everything about glyphosate toxicity, but does not identify limitations or weaknesses in the way the US or Europe regulatory agencies assesses human health or environmental risks.


The authors also pose some bad arguments.  They put forth that the USDA found the highest number of samples containing agricultural chemical residues in a food (soybeans), to be glyphosate, with malathion (a pesticide) being the second highest contaminant residue.  They calculated the glyphosate was 72-fold greater than malathion and concluded that these residues to be much higher in other foods (plant and animal) based on the series of requests by Monsanto to increase tolerance levels in food and animal feeds.  They did this without looking at application levels, rates or times, toxicity potential, or food groups; no actual data were evaluated.


The authors also put forward the idea that academic and research institutes have better toxicology study data because they publish the results in peer-reviewed journals, but regulators rely on unpublished, non-peer reviewed data generated by the registrants.  Actually, the data required for pesticide submission must be conducted according to validated test guidelines and under Good Laboratory Practices (GLP) conditions.  GLPs are seldom followed in academic and research laboratories, but must be followed by the pesticide registrants.  They are not there and enforced to focus largely on avoiding fraud as stated in the article.  First, GLPs ensure that all findings, the good, the bad, and the ugly, are documented and presented to regulatory agency(s).  Regulatory agency risk assessors must independently review the data and determine whether the study is acceptable according to validated test guidelines.  A weight of evidence is conducted to integrate the body of evidence (positive and negative studies) to determine the regulatory point of departure to ensure human health and environmental safety.  With academic and research laboratories results, there is a significant publication bias where only the significant positive findings are accepted by the scientific journals (just try and publish non-findings) and the authors can pick which journal to submit and resubmit.


The German Federal Institute for Risk Assessment was picked on by the article, for not using a scientific quality and relevant tools in identifying useful glyphosate toxicology studies[3] but instead relied on outdated methodologies such as Klimisch score.  The Klimisch score is the current standard tool used to check the reliability of a toxicology study.   Academic studies can achieve a good Klimisch score, even if they are not carried out to GLP standards.  However, frequently the reports of such studies suffer from insufficient description, including the identity of the test material.  Alternatives and improvements to the Klimisch score have been proposed since its introduction.  The Klimisch score has been criticized due to its oversimplification of certain studies and identifying adverse effects might be missed, but this is a criticism of the application of the tool, rather than the tool itself.


The EPA has not dropped the ball, at least not yet, when it comes to tracking the myriad ways people are exposed to glyphosate, and its estimates on safe exposure levels. The Agency reviews not only toxicity studies on the pure compound, but also its formulation (mixture).  The allegation that regulatory authorities do not test the formulated product is misleading and not based on knowledge of the pesticide data requirements.  Can we just wait until EPA’s updated risk assessment and final re-registration decision on glyphosates scheduled to be completed this year before we start pointing more fingers and making incorrect allegations based on misinformation?
Author:  Ray York, RG York & Associates LLC


[1]  http://www.ewg.org/agmag/2016/02/epa-isn-t-protecting-americans-monsanto-s-roundup


[2] Myers, J., Antoniou, M., Blumberg, B, et al. (2016).  Concerns over use of glyphosate-based herbicides and risks associated with exposures: a consensus statement.  Environmental Health 15:19, p 1-13.

[3] Renewal Assessment Report, Glyphosate Residue Data, Vol. 3, Annex B.7, Dec. 18, 2013, RMS: Germany, Co-RMS-Slovakia

 

 

 

 

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