Monday, July 21, 2014

If They Say "Agent Orange", Stop Listening

Some people are truly slimy.  Few things frame the use of fear to attempt to motivate opinion on transgenic crops like the increasing use the phrase "Agent Orange".  It seems that you can't read an anti-GMO opinion lately where the author does not allude to the tragic use of this military agent, now in the contemporary setting of a farm near you!   And of course, they'll tell you it will be in your food.  And in your baby food.  And in your breastmilk.  It is about fear.  Period.

Agent Orange was a collection of herbicides, namely 2,4-D and 2,4,5-T, that were produced by at least sixteen companies during the Vietnam War era.  They were used as defoliants, key weapons to expose an entrenched resistance in a dense jungle.  These compounds are synthetic auxins, a class of plant hormone that inspires rapid cell division and elongation growth.  Essentially, a plant grows itself to death.  

The 2,4,5-T preparation was contaminated with a potent dioxin, a chemical directly responsible for the tragic health impacts on soldiers and civilians. 

2,4-D has been the most widely used agricultural chemical in the last century. Nobody ever cared or thought twice about it until plants were genetically engineered to resist it-- now it must be villianized.


Of course the opinion piece in an Oregon paper doesn't mind going there.  What better term to flip out a state rich with those that believe anything first, and ask science questions never*?  A local physician and a retired EPA scientist sure don't mind using it-- it's scary! 

It comes up again and again in the mindless comment stream. 

You'd think a physician and a retired EPA scientist could build an argument based on facts rather than fear.  When you've got nothin', play the Agent Orange card.  

This is how you know there is no legitimate evidence backing the labeling initiatives.  There is no science, no reason.  There are no data or conclusions.  You can't motivate Joe and Jane Six Pack away from the Kardashians to engage them with scientific information, but you can give them a major-league chemophobic freak out by conjuring up images of an weapon of war, now applied to food. 


The minute you read or hear the phrase Agent Orange, know you are being manipulated by false pathos.  Tell them to save the hyperbole.  If they have to scare you to vote for labeling with false associations, then it probably isn't such a hot idea. 

*After my original post a received a few comments and emails from proud Oregonians that didn't feel this characterization was appropriate.   After a short exchange with one friend (K.L.- YES YOU) she stated, "The place does have quite a few flakes",  which I think is consistent with what I said.  Not everyone there is goofy, duh.  Some of my favorite thinkers are there at OSU and OU, and a bunch live in Portland just 'cause they love it.  So kudos to Oregon, you've never done me wrong, but in my estimation you're up there with Texas, Florida and Vermont with those that might put belief over science... not quite California, but keep trying! 

Saturday, July 5, 2014

Inconvenient Glyphosate Math

There is a lot of discussion about glyphosate use and its relative toxicity lately.  For activists, it is an easy target, as it is easy to put glyphosate in the ag input hopper in close association with DDT and other goodies that freak out affluent white people.  You can read on any activist website or comment section that "Roundup Ready seeds are doused in massive amounts of glyphosate- getting this deadly chemical into your body".  Farmer David Walton did a really nice discussion of this over at Genetic Literacy Project recently.

However, I've had this blog entry half done for ages and with the topic coming up over and over again, I thought I'd expand on David's excellent report and provide some more relative numbers, especially with respect to toxicity.

Let's do some math. 

-- How much is this massive amount

-- When is it applied to the crop? 

-- How do amounts used translate to toxicity risks? 

Massive Amounts? 

For soybeans, the application rate is 0.75 lb active ingredient / acre.  I can't work in lbs, mostly because I can't figure out why we don't spell "pounds" as "lounbs".

Speaking metrically, that's 340 g of active ingredient per acre.  That's about the amount of weight/volume in a 12oz (why don't we spell it "ounze" can of soda (or beer; doesn't matter).  That number assumes that glyphosate is about the density of water, which it's not.  It is 1.70 g cubic cm, so that 12 oz can is really about 7 oz big.  That doesn't matter so much.

Now spray that little pop can of active ingredient over an acre. I'll wait. Make sure you have enough to to do the whole thing.

Or we can do the math instead.  An acre is 4047 square m.  That means 83 milligrams per square meter. My 7th grade science teacher Mr. Herzing said, "A milligram is about the weight of an insect wing."

Wow, that seems like not much!  But how much soybeans does that get ya?

Soybean yields in 2013 were 43.3 bu/acre and a bushel weighs 60 lounbs, so that's about 2598 lbs/acre, or 1180 kg/acre.

To make it relatable to herbicide used, we need to get it down to square meters. That's 291 g soybeans per square meter.

So 83 mg of active ingredient is needed to produce 291 g (0.640 lbs) soybeans.  Of course these numbers assume one application, which is likely not the case, but it still is a tiny amount.

Here is what 83 mg looks like.  Here I weighed out one of the most deadly chemicals currently responsible for chronic health problems in the USA.  That's sucrose.

Timing of Application

But glyphosate is not applied when soybeans are on the plant.  There are critical windows when weed suppression is most important. From what I understand this is when plants are smaller than 30 cm tall (one foot), and this critical weed free time is typically 4-6 weeks after planting. Once plants establish they can suppress weeds a bit on their own by shading them out.

Application after the R2 stage is not legal.  That 83 mg per square meter is not being sprayed on food products.

The product also works best if it is not 'wasted' by spraying it on the soybean plants themselves. The targets are the weeds, so most of that 83 mg per square meter is targeted to rows and not to the crop plant.

Glyphosate is typically applied between first trifolate leaf emergence and flowering, before food items are on the crop.

The next kinetic to consider is that glyphosate is degraded, both in the plant and in the soil, so that 83 mg per square meter is going away as soon as it is applied. It is not taken up by roots, so what is not applied to the plant itself goes into the soil and is degraded with a half life of 3-130 days depending on soil type and other factors.

Jeffrey Smith's Institute for Responsible Technology says that it persists for 22 years, which is certainly possible when a half life is 130 days. After 22 years there likely are a few molecules still hanging around at least if the math is right.

The only way it gets into the plant is through foliar application- in other words, if it does not get in through the leaf, it does not get in.  In the plant itself the compound is turned over too, and how much gets in depends on many factors. There's another inconvenient bottleneck to think about.


A prospective study by Roberts et al., 2010 examined cases of self-poisoning with concentrated glyphosate. This is the 41% stuff you buy at the hardware store, then dilute to make a working solution. It is usually applied at about 1%.  In their analysis 27% of people had no symptoms, 60-some % had mild symptoms and in 19 of the 601 cases people actually died.  These folks were older, and had blood concentrations of 734 micrograms/mL. When you do that math, that means that there is 4 grams in the blood (assuming 5 liters) active ingredient.

Holy cats!  Look at the stuff on the scale in the photo above.  Multiply that amount of active ingredient by 48 (4000 mg/83 mg), and then double it (because the solution is 41%) and then inject it... that's what it takes to kill yourself with the concentrate! 

If you wanted to do this with the standard application amount, that would be about three liters of Roundup.  

Let's go back to the soybeans.  Let's assume that 100% of the 83 mg m-2 ends up on the plant and magically all sequesters into the soybean itself.  If there are 42 bushels per acre and 60 lbs per bushel, that's about 1.36 lbs per square meter, or 0.62 kg.  That comes out to 133 mg/kg or 133 ppm.

USDA numbers show that the highest detectable amounts are typically 20 ppm, but let's roll with 133 ppm.

The LD50, the amount needed to kill 50% of rats consuming the dose, is about 5000 mg/kg.  For simplicity let's use a 100 kg person, 220 lbs.  To get to the LD50 dose of these 133 ppm soybeans they'd have to consume 3759 kg of soybeans, or about what is produced from three acres of soybeans!

Sure, lethal doses are not a great benchmark and most people are worried about residues and what effects small amounts can make.  However, 20 ppm, the highest amount allowed by the USDA, diluted in a human where we know how the stuff is broken down and excreted, turns out to be a biologically meaningless amount by all known standards.

And keep in mind that work from Seralni's lab (Richard et al., 2005) shows that placental cells in a dish begin to show problems only approaching 1% glyphosate.  That's one part per hundred, or 10,000 ppm.  That's to kill a flimsy layer of placenta scum in a petri dish!


There you have it.  While opponents of biotech paint glyphosate as a dangerous and deadly compound, drenched in massive amounts onto food-- it really is nothing like that at all.  It is a relatively innocuous compound that is used in small amounts. Farmers use it to control costs, save tilling, fuel and labor.  While not perfect, it is good technology where the benefits far outweigh the risks, that is, if we take the time and do the math.

*** and of course, feel free to check my work and let me know if you find any problems ***

Wednesday, July 2, 2014

Injured, Sidelined, and Hating It.

I live a rather high-strung, active life.  I don't have kids, I have a job I adore, and have good friends that participate in a vibrant sports community.  Most people don't know the whole story.  I don't talk about it much.

Today I'm complaining, so if you are reading this looking for some snarky criticism of pseudoscience hit your back button and go away.  I'm at home early tonight, going completely nuts.  Here's why.

May 31, 2014 I found myself face down on the pavement, scraping forward from 25 mph to a dead stop attached to a bicycle.  I was riding in the thick of a fast-moving pace line on a usual Saturday morning club ride.  We did a fast 50 miles from Gainesville to Melrose, FL and back.  When coming back into town, the rider in front of me got a flat, hit the brakes, I hit him and went down.

I fell correctly, got up, dusted off, took a deep breath, and rode my bike back to my car about another 5 miles away. My left knee swelled up like a balloon, but a bag of frozen peas, a few beers and a handful of aspirin would keep me vertical for a few weeks.

And I'm done with bicycle club rides with dangerous unpredictable people that have too much legs for their brain to handle.

Sure, on May 31 it seemed like I'd bounce back fast... little did I know...

Three weeks later the swelling was gone, but there still was something not right.  It was a soreness, especially when I slept, in the joint and in the medial tissues.  An MRI showed a torn MCL and probably meniscus damage.  I opted for a conservative approach by declining surgery, but now I'm in a full-leg brace for 4-6 weeks. The meniscus damage might be from a previous surgery, so my doctor decided not to go digging further.


I work my job as a scientist and Department Chairman literally 80 hours a week, on a normal week.  My day starts at 5-5:30 AM, I answer emails, then go to the gym 6-7 AM and then get to work between 8-9:30, depending on if I want to handle more emails or write from home.  I don't eat lunch, don't take breaks.  Don't need to.  I'm having too much fun.

However, I do look forward to my nights. I do something exercisey every weeknight (except Friday), and then go home to eat something and work more until 11pm, when I catch the first two segments of The Daily Show before crashing for the night.

This is my rut, my mid-life crisis.  Most guys get a girlfriend or a sports car.  I take on more professional responsibility.

The daily workouts are my salvation.  Monday at 6:30 we run the stadium for one hour.  It is a hard red-line workout that leaves us all with shaky legs and bruised souls.  Tuesday is a 3.0 mile run from World of Beer, and when everyone else goes off to grab a cold one I run out to Canterbury Equestrian Park for karate practice at 7:30. We work hard and kick the snot out of each other for an hour or so. Wednesday is a fast 30 mile bike ride at race-pace with a great group that leaves me in the dust after 20 miles.  Thursday is the Tipple's Run (4.0 miles from a local beer store) and then more karate practice. Saturday and Sunday are long rides or runs early, then great days to have undisturbed work time.

It is the friends and colleagues that make it do-able.  It is hard workouts with sweet people, and wonderful scientists at work that make it worth it. At 47 years old I'm feeling really strong.  I am (was) running well and riding fast and my scientific career is going well.

But here's where the depression sets in.  I was supposed to be in Reno next week for USAKF Nationals.  I was preparing well, I was feeling really good, and as of May 30 hoped to place high in the Masters Division.  I took bronze in 2012, and 2014 was shaping up well. I was scheduled to practice with a group at another location, lots of sparring with fast 20-year olds that would give me a good taste of high-end competition and make me really solid for the July competition. I would have likely been competitive.  Now, I'll be home.

I also hoped to belt test for my next degree in October, but that's probably out too.

It is day one of "4-6 weeks" off of the bike, running and karate, doctor's orders, and I hate it.  It is extremely unlike me.  I don't want to write, I have no interest in much at the moment.  I'm mindlessly surfing the net and reading news.  He says that if I don't stay off it we'll be looking at a surgical reconstruction, and that'll have me sidelined for months.

Now that I wrote this I just want to erase it.  I don't want a pity party, I don't really want anything.

It is just amazing to note how when you have a good connection to physical activity it really affects your life.  I'm still getting to the gym in the AM and maybe can do double time there, but it is not the same as a good run or hard bike ride.

C'est la vie.

So thanks to Gainesville friends that make it so much fun.  I'll be back and this episode will get smaller in the rear-view mirror.  However, sitting on the front end of it looking at a calendar full of empty boxes and an uncomfortable, restrictive robotic brace from ankle to crotch is not the way I'd like to live. I have to keep reminding myself that this is only temporary, and I can take it off on Elvis' Death Day.  Wow, that's a long way away.

Sunday, June 29, 2014

When Liars Cross the Line - GMO Insulin

I was shocked, but not surprised, when a internet meme from GMO-Free USA popped up on my Facebook page:

GMO Free USA (and GMO Free Canada, eh) really shows their true colors with this one.  The referenced paper has nothing to do with GMO insulin, other than saying that it is better than the stuff from animals.

The rocket surgeons over at GMO Free USA really stepped in it this time.  They are using their fear-based misinformation machine to now scare people away from life-saving insulin therapy.  We all depend on insulin, a hormone synthesized in the Pancreas, to control blood sugar levels. Elevated blood sugar can lead to a variety of metabolic disorders and long-term damage to various organs. Type II diabetics produce too much at first, leading to insulin resistance, a state where the body just does not respond to the hormone and blood sugar levels remain high. Eventually type II's do not produce enough, so they need to control blood sugar with drugs, or in some cases administer insulin injections to manage their levels. 

Insulin for human use used to be purified from the pancreas of slaughtered animals.  The preparations obviously would contain other potentially reactive proteins, which presented an attractive solution for recominant DNA technology.  Recombinant insulin was first generated way back in the 1970's, and today is generated in yeast or E.coli in massive fermeneters.  The recombinant (GMO) insulin is infinitely more pure, safe and available. 

So why would the bone-heads at GMO Free USA make this claim?  They are not alone- the same claim was also shown over by the guy with minimal scholarly chops, Sayer Ji.  I'm pretty sure he read the headline and didn't even read the paper (I did).  It is not the first time, as he also reported on the title of the Glyphosate in 75% of Water Samples paper that was not even out, and I got the first copy from the authors. 

GreenMedInfo once again shows that the truth shall not stand in the way of agenda, 
even if people die in the process. 

They may be dead wrong on this one, but at least they are being intellectually consistent. If a bacterial gene in plants is magically dangerous, a human gene in yeast must be one of the most poisonous concoctions on earth. Of course, we all know that it is beyond perfectly safe when used correctly.

What did the paper really say? 

Well, that would require reading it, which I did.  Here's the scoop. First, it does not mention "GMO Insulin" or even compare recombinant insulin to non-recombinant. 

Is that what GreenMedInfo and GMO Free USA say? Absolutely not!  They should be admonished for their scare tactics.  This crosses a line. 

The gist of the paper is simple. If you give insulin to someone that is not diabetic, the body reacts to the improper presence of insulin, which is a reactive hormone.  After prolonged administration of insulin symptoms of Type 1 diabetes can be observed in some genetic backgrounds.  The study by Nishida et al., 2014, in the Journal of Clinical Endocrinology and Metabolism is a short report that expands previous observations to a set of six individuals that were being tested for this response.  The interest was to determine if there was a genetic component that could be isolated in this short pilot study. 

The report does state that the individuals that have a specific HLA Type (a collection of blood cell surface antigens) are more susceptible to the insulin-triggered development of Type I diabetes.  They link this to specific genetic markers that are present in Japanese populations.  It is much more complex than this, but in a nutshell... 

A Dangerous and Deadly Agenda
Even Health Ranger Mike Adams is not stupid enough to touch this one. Once again, anti-GMO activists like those at GreenMedInfo and GMOFreeUSA rub their crystals and align their shakras in a message that stands to strike fear in those using safe and dependable insulin therapies.  This kind of fear mongering is just an extension of their normal routine-- condemning good technology and products to fit their own agendas, even if it causes harm or death to others in the process. 

Tuesday, June 24, 2014

Predicting the Future -- Seralini Rat Paper Redux

"I don't need a crystal ball; I have a crystal brain."
--Adam Carolla

Today the famous Lumpy Rat paper was published by Seralini and colleagues.  I should say RE-published because it is basically the same content published in 2012, that was later retracted from the journal.  Personally, I was glad to see him attempt to publish it again.  The literature is where the conversation should happen, and if the work is of good quality it will be reproduced and expanded upon. 

If the work is of poor quality it will die a scientific dead end, cited only by the same authors in future papers with no additional progress.  Kind of like the rest of the Seralini work. 

Unfortunately the general public doesn't follow the scientific conversation. People only pick the monologues they agree with, and a single flawed study from a biased lab carries as much weight (or more) than a thousand agreeing reports from 800 different groups. 

It was disappointing to see that Seralini's group didn't even try to fix the obvious and egregious errors and omissions.  They even took on a snarky commentary in their Competing Interests section, stating, 

"The author(s) declare that they have no competing interests, and that, in contrast with regulatory assessments for GMOs and pesticides, they are independent from companies developing these products."

... which is amazingly unprofessional, off base and not scientific.  It is a political statement.  The journal and the editors should be ashamed. 

However, all of this comes as no surprise, as back on March 3, 2014 I wrote in this blog: 

"It is conceivable that the data may find publication in a smaller low-impact title, like Carman's article in the Journal of Organic Systems, an apparently online only journal with no impact factor and limited editorial rigor.  The credulous anti-GMs don't understand science, let alone what the quality of the venue means." 

Some may consider this prophetic, but it is easy to see the future when the future is painfully obvious.  Seralini appears to have quite an ego to sustain, and the retraction from an okay journal must have hit pretty hard.  It was almost certain that he'd attempt to republish the work-- but it isn't going to a decent journal.  Today it came out in Environmental Sciences Europe, a journal with a less-than-rigorous grasp on reality, a clear anti-biotech slant, and the journal that has published such duds as Benbrook's famous paper on increasing pesticide use that used interpolated and extrapolated data (because actual numbers didn't exist).  

It boils down to this-- if these data were significant, if the experiments were good, and the interpretations sound, this would not be buried in the depths of a crappy journal.  If there was hard evidence that our food supply truly caused tumors, it would be on the New England Journal of Medicine, Science, Nature, or maybe Cell if he wanted to go slumming.  But it's not there.  It is in a tiny, obscure journal that has quite a visible agenda, and that's the only thing visible about it. 

And that's where it belongs.  Let him have his day in the sun.  History will not remember him for his science. It will remember him as a disgraceful hack that let personal agenda affect adoption of safe scientific technology.  He'll be the guy that fooled millions with low-quality data.  

It is very sad, because I'd rather be writing blogs about exciting science and new findings.  Instead we're back to this nonsense.  Luckily, it will slowly disappear into time, like Puzstai's lectins, Huber's mystery organism, and the rest of the alarmist junk never published or never reproduced. 

It does not take a crystal ball to see that. 

Monday, June 23, 2014

Voyager's Gold Record- Vintage Technology for Extraterrestrial Audiophiles

I'm a huge Sagan fan, and even today I am surprised at how well his words and the 70's series resonate gloriously.  But WTF is with the Gold Record on Voyager? 

The records were constructed of copper with a gold plating and contain Sounds of Earth.  They were placed on both Voyager spacecraft launched in 1977 and now are somewhere out past Pluto.  Sagan noted, "The spacecraft will be encountered and the record played only if there are advanced space-faring civilizations in interstellar space (that have a turntable)." 

Shot into space, any extraterrestrial can enjoy "Sounds of Earth".
If they have a good thrift shop they might find a way to play the damn thing.

Of course, back in the 70's we were pretty sure that the LP was here to stay.  I remember thinking they should have shot the KISS Alive II double album into space too. The problem of launching an LP into space is that the receiving party has to figure how to use it.  If such a thing were to land from space in some random locale in the USA, the finder would either grill it, rape it or pawn it. Unfortunately the utility of a 1970's style LP record is highly dependent on the sophistication of the receiver. 
On our next space probe we should include a turntable, one of those cool ones with that arm that drops a stack of records one-by-one.  Include that weird plastic swastika-thingy that you had to use to play 45's in case they find one on another space probe that liked a few Sounds of Earth but didn't want to commit to the whole album. This is a great idea for a Kickstarter campaign.

The B side is the lousy sounds of earth, like the kid screaming behind you in the airplane, that clicky noise your car makes when you turn the key and the battery is dead, and the noise the dental drill makes when it really starts to dig in. 
We also need to include a dime for them to put on the needle in case it skips. Nothing worse than the Sounds of Earth with an annoying "ka-thunk" every revolution. 
The whole thing is kind of charming in that it was the best we had at the time, and kinda cute that we'd see the LP record as a durable technology that might transcend the ages. It was gone in a decade. It is a reminder of how far we have come in a short time, and a prelude to how exciting our future must be. 

Sunday, June 22, 2014

DNA Damage and Glyphosate? Critical Evaluation of a 2007 Report

A question appeared over on and I thought I'd take a stab at it.  I remember looking at it briefly awhile ago, but it didn't stick in my brain.  Maybe because it was not worth sticking there.

Last night I took a critical look at this work.  If you take the time to read it you find that even the authors have many mundane explanations for the results.  However, the title becomes a headline and is part of the glyphosate=danger mantra repeated by low-science-resolution readers that seek confirmation of their biases.  Judging by the capitalization in the question, the person with the question even cut-n-pasted the title. Not too many calories being expended to sort out this mystery!  However, education is my goal, so here goes... 

Question on GMOanswers:  Can you comment on this study about DNA damage due to Roundup Evaluation of DNA damage in an Ecuadorian population exposed to glyphosate?

The report you refer to is Paz-y-MiƱo et al., (2007), a "Short Communication" published in the journal Genetics and Molecular Biology, a small Brazilian journal (Impact factor 0.73, so not a well-recognized journal). So we're starting with a Short Communication in an obscure journal. 

As usual, opinions formed from reading titles are not terribly accurate, and don't match the data within the report.  As evidenced by my analysis here, a conclusion from a title takes a lot of time to address!

Ceasar Paz-y-Mino has an okay publication record and studies a number of regional issues using his expertise as a cell biologist. This report tests assesses "DNA damage" using what's called a "comet assay", an assay where cells are placed into an agar matrix, lysed and subjected to an electric field.  DNA is charged, so large DNA pieces move to the positive pole.  Damaged DNA moves faster because it has greater mobility- that's the basis of the assay. The DNA smears out as a blob with a streak after it, resembling a comet. 

In this report 24 people from an ag intensive area where glyphosate was used were compared to 21 in an area 80km away.  Blood was drawn "between 2 weeks and 2 months" after glyphosate application to the crops. There is one table of data showing that the DNA from those living near the farm (50% tested were 200m-3km). 

The results show consistently higher migration in the "exposed" group, suggesting more damage, according to the authors. 

Before we get too excited about the results:
1.  Glyphosate moves quickly from the body.  After two weeks there would be negligible effect, if any, from acute exposure. The samples could have been from people tested two months after exposure, the authors don't specify. 

2.  The authors say that the "exposed" group had sprays directly over the homes in 50% of cases, and that applications were "20 times the maximum recommended application rate for the formulated product, which may explain our comet assay results"

If there's one thing we can learn from this paper it is that someone is not reading a label very closely before firing up the crop duster. 

So directly spray the homes of the workers with 20x the normal concentration, and then measure if there's something screwy going on.  Hmmm.  I wonder. 

3.  But all that is likely a moot point.  Glyphosate is rapidly removed from the body and in no cases has it been demonstrated to damage DNA or even carcinogenic (it is classified as "not carcinogenic" even by the strictest standards).  What is happening? 

Here are additional considerations and interpretations: 

First, if these workers were tested 14-60 days after being sprayed with 20x glyphosate, what else are they spraying down there imprecisely and at levels far above recommendations?  Are these chronically ill people from prolonged exposures to 20x ag chemicals sprayed on their homes?  This would be a better explanation, unless the authors knew that the occupational exposures were purely glyphosate.

But the best explanation--  "Blood samples (from the unexposed group) were collected and processed as for the exposed group, but not concomitantly."

Bingo.  The authors counted on one single replicate that was processed at different times. How the blood was handled, how it was prepared... all could easily account for the results seen.  The fact that it was one replicate is also quite telling.  I'd never publish with fewer than three on this kind of test. 

The best thing that could be said is that the data show a potential starting point.  It would have been good to see the data and have the controls and treatments collected and processed blindly and at the same time.  

Conclusion:  Maybe good work, maybe not. Maybe trustworthy data that are a hint of things to study further, maybe not.  The methods and data presented do not rigorously support the authors' conclusions.  It has been seven years since this study and no further evidence to support the DNA damage conclusion.  In a 2011 report by the same authors, glyphosate showed no effect in DNA damage in a larger test with greater resolution in Colobmian/Ecuadaoran populations.

The most likely explanation of the findings is that the cells in one group broke down or had some other damage during handling leading to the results observed.  That's why there has been no additional follow up on this study.