Pesticides and Food: It’s not a black or white issue — Part 3: How dangerous is glyphosate?

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Although pesticide toxicity and biodegradability has decreased overall during the last few decades, many consumers are still worried about pesticides. They are especially concerned with specific pesticides that are portrayed as dangerous by the media.

A bottle of the pesticide RoundUp

Foremost among those is glyphosate.

Glyphosate (the active ingredient in RoundUp) has drawn attention in the media in recent years, alleged by advocacy groups as being toxic and dangerous. But study after study has shown that it is one of the least toxic herbicides on the market and does not accumulate in the soil. How does glyphosate fit into the context of all current pesticides? How does glyphosate toxicity compare to other pesticides? And how does glyphosate toxicity compare to other common substances?

3: How dangerous is glyphosate?

Before understanding the toxicity of glyphosate in the context of other pesticides and substances, it is important to clarify what toxicity means. Toxicity, the degree to which a substance can damage an organism, can be measured and compared in various ways. Acute toxicity refers to the immediate effects of exposure to a certain dose of a substance. Chronic toxicity refers to the effects of being exposed to a certain dose of a substance multiple times over the course of a certain period, for example, once a day for months or years. Acute toxicity is what we think of when someone gets poisoned by a substance. Chronic toxicity is usually what most consumers are worried about concerning pesticides: what are the effects of being exposed to small doses of pesticides, on our produce, for example, over a long period of time?

Editor’s note: This is part three of a six-part series on pesticides and food. Read part one, part two, part four, part five, and part six here.

For every substance, what matters is at what dose the substance becomes toxic for a specific organism, like an insect or a human. For both acute and chronic toxicity, substances are not “toxic” or “not toxic.” Even water is toxic if you ingest too much of it at one time. In addition, a substance can have high acute toxicity, and low chronic toxicity, or vice versa. Acute and chronic toxicity are not necessarily correlated. The point is, claims that glyphosate “is toxic” are not meaningful – only by comparing a pesticide’s acute or chronic toxicity with other well-known substances do we get a true understanding of the safety or danger of that pesticide.

Now, back to glyphosate. Glyphosate makes up 25% of all pesticides used in corn in the U.S.

Pesticides used on corn:

25%     Glyphosate

75%     All other pesticides

However, it only accounts for 0.01% of the chronic toxicity hazard of all pesticides used in corn.

Chronic toxicity hazard from pesticides used on corn:

0.01%     Glyphosate

99.99%     All other pesticides

This suggests that glyphosate is much less toxic than other common pesticides.

Read more about glyphosate in the GLP GMO FAQ: Is glyphosate (Roundup) dangerous?

It is helpful when analyzing toxicity to compare pesticide toxicity with other common substances. For example, caffeine is over ten times more acutely toxic than glyphosate. To die from poisoning, a 140-pound human would have to:

Comparison of how much coffee and how much glyphosate would cause an overdose in a human.

Compared to other pesticides and even things we find in common food and drink, like caffeine or vitamin D, glyphosate is low in toxicity.  One might wonder how it is that a substance specifically designated to kill things could be less toxic to humans than a vitamin that is necessary for human health? This lies in what is known as ‘mode of action’, that is, how the substance actually harms its target. Glyphosate is designed to kill plants and it does this in a very specific way — it inhibits photosynthesis, depriving plants of energy. Because humans don’t rely on photosynthesis for energy, glyphosate’s toxic properties as an herbicide are harmless to us. However, many are still suspicious and fearful of the possible consequences of regular glyphosate use. The use of pesticides is always about trade-offs. We need pesticides to produce enough crops to feed the world. Protecting and increasing crop yields through the use of safe pesticides is more sustainable and environmentally-friendly than letting land and resources go to waste because of unsubstantiated fears concerning chemicals.

Of course, the safety and health of humans, animals, and the environment are critically important. The use of specific pesticides always needs to be weighed against the alternative: which alternative pesticides will be used if one is banned? Are certain pesticides allowing for more sustainable farming practices that will be halted if other pesticides are used?

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In the case of glyphosate, possible glyphosate bans in European countries may lead to less sustainable farming practices along with the possible use of more toxic herbicides. Specifically, glyphosate is an effective way to prepare fields for seeding by getting rid of weeds and plant cover. By using glyphosate, farmers had been able to reduce tillage substantially. Tilling the soil is a farming practice that also helps prepare fields for planting, but it increases erosion, reduces biodiversity of insects and animals in the soil and releases greenhouse gas into the atmosphere. Banning glyphosate could actually lead to the use of less sustainable farming practices. The balancing of pros and cons in pesticides and their interaction with farming practices is necessary regardless of whether pesticides are organic or synthetic. In the next post of this series, I will compare toxicity between common synthetic and organic pesticides, highlighting the complexity and variability in pesticides within both systems of farming.

Kayleen Schreiber is the GLP’s infographics and data visualization specialist. She researched and authored this series as well as creating the figures, graphs, and illustrations. Follow her at her website, on Twitter @ksphd or on Instagram @ksphd

Marc Brazeau is the GLP’s senior contributing writer focusing on agricultural biotechnology. He also is the editor of Food and Farm Discussion Lab. Marc served as project editor and assistant researcher on this series. Follow him on Twitter @eatcookwrite

This article was originally posted on the GLP January 29, 2019.

8 thoughts on “Pesticides and Food: It’s not a black or white issue — Part 3: How dangerous is glyphosate?”

  1. Moderator – your command to Disqus to ban these two trolls on 6/6/2020 did not work. Please try again.
    Note that all notifications of “this comment was deleted” were intentionally generated by me to dump the illegally hacked downvotes of the Ted Miner troll, totaling over 9,500 downvotes since Jan 2020 on the GLP site.

  2. FYI…….I came here out of concern for kids’ development and got attacked by Solar Surfing. I’m just a a mother and teacher of kids for over 25 years. I
    came here out of concern about kids and what I have seen in my school
    and community over the last 15 years. SOmething is causing an increase
    in Special Ed and autism services, and I for one don’t think it’s
    vaccines. I think certain kid’s immune systems are jacked up and yes, a
    vaccine insult can precipitate other things. SO then the question is,
    what is causing low grade inflammation in humans, of which, kid’s are
    particularly vulnerable, so it appears? I am also seeing a lot more
    psych issues and chronic health problems (inflammation) among adults in
    the last 15 years. SO what has changed? I do know one thing has changed,
    and that is farming harvest practices using roundup.

    SO I come here, and
    this is what I find. Solar jerk starts calling me a conspiritard,
    lumping me in with his reaction to RObert Jones. Unreal. I bet RObert is
    right. You do have a personality disorder Solar Serf. It’s likely few
    people can tolerate your presence. I bet you have few people who call, little acknowledgement from you family, and no involvement in the community. One moment you say the world is overpopulated and in another breath you pump polluting farming practices to feed the masses. I’m sure there are many other contradiction rotating around your small mind. You may in fact be on the spectrum,
    and your rigidity is a reflection of your mild autism.WHen mild autism attributes get mixed with a personality disorder you get a nasty mess of a person. Eat well. Get a
    life Mr. Solartard.

  3. Readers note – between Dec 20, 2019 and Jan 5th, 2020 a real idiot troll attacked this thread relentlessly, timing his attack of posts and conduct prohibited here to coincide with the holiday off for GLP staff, meaning there was no moderation available.
    This Robert Jones account was opened specifically to troll this thread only, with 83 attacks, and it has been inactive ever since. Once he started, the cyber criminal hacker Ted Miner, who abuses 22 fake sock puppet Disqus accounts, unleashed his bot program that leaves 2 downvotes a day, like clockwork, every day for the last 3 months. That Machiavellian sadist troll is banned from Disqus by the GLP. I have removed over 3,500 illegally hacked downvotes by him in this thread he deposited over 3 months. Please tell the GLP moderator to police its threads so this educational site can not be abused by anti-biotech trolls.
    Also consider calling the Behavioral Institute of Atlanta where this hateful ignorant lying troll Robert Jones is employed. Tell them how revolted you are by his hateful aggressive attack on this thread by posting a barrage of pseudoscience lies and conspiracy theories. Ask the Institute if this moron represents the caliber of workers they employ. Would you send your child to be cared for by this jackass?

    • Notice how this asshole Ted Miner immediately began illegally hacking the downvote option here again as soon as I removed his accumulated steaming pile of cheating downvotes. Click on the downvotes to verify they are his fake accounts. Ted Miner’s annual trolling tally on DISQUS for year seven of criminal abuse:
      7,110 posts for 2018 at an average of 17.5 posts per day. This is almost exactly half the number of posts he made in 2017 but still a huge amount of Disqus abuse other civil science respecting users detest. Please flag him for spam and report his accounts.
      His various sock puppet accounts posted as follows:
      razorjack was most prolific at 776 posts
      Duncan DeBunkerman next at 619 posts
      E. Sandwich with 618 posts
      Goldfinger 603 posts
      SUNNY with 584 posts
      GOOSE with 441 posts
      Sparkle Plenty with 415 posts
      Wally 386 posts
      patzagame with 285 posts
      Debbie 3554 with 200 posts
      Peaceful Warrior with 377 posts
      Cletus DeBunkerman with 269 posts
      Even the original Ted Miner showed up for 85 posts
      Not content with 11 DISQUS accounts, Ted Miner invented four more for 2018:
      Anne Temple with 998 posts
      ROBIN with 549 posts
      Byron Smith with 416 posts
      Papa Ray with 272 posts
      Rob Bright with 604 posts
      sir_Ken_g with 198 posts
      jbd, Hortense DeBunkerman, William, Popeye, Liam Pederson, Milo, Tbony and Chas Erikson are his newest fake accounts in 2019. Also very suspect is the Lisa Markarchuck account. Both Ted Miner and Lisa are banned from the Genetic Literacy Project, NPR, PBS and Mother Jones.
      Two of his retired (deleted by abuse reports) accounts – TZ and T Zena, and there are more – S.G. and grinninglibber also exhibit the same behavior and will be added to this list.
      With 17 accounts to log into and upvote each of his 7,110 posts, it is no wonder Ted Miner couldn’t reach his higher post number for 2017. On top of that he had to downvote and flag all the posts of other DISQUS users he disagreed with 13 or 14 times. Ted Miner is a mentally ill Machiavellian sad ist with a dopamine addiction he feeds by abusing Disqus.
      Now in 2020 Turd has employed bot programs to downvote posts at sites where he has been banned from commenting.

  4. Key excerpts from the intense troll attack here by Robert Jones were just forwarded to the Behavioral Institute of Atlanta receptionist and administrator today, May 18, 2020. The GLP deserves an apology and retraction.
    UPDATE – Robert Jones is now banned from the GLP Disqus forum.

  5. You’ll note, Latvia and Greece just announced they will not allow planting of gmo crops. Apparently people in those governments are not sure these products are safe for humans nor the environment.

    • What we actually note is that the kpalmer account is now banned from the GLP. Catch a clue, troll.

      Intelligent consumers note that 5 African nations adopted GM crop science in the last year and Russia ended its hostile propaganda war against GMO science as it announced it is now developing 30 new GM plants and animals. You’ll note that the total acreage of GM crops has been increasing steadily every year and we have planted one billion acres of Bt crops with no unintended consequences: https://allianceforscience….

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