Glyphosate found in 100% of wines tested in California–Reason for concern?

The headline was scary enough:

Widespread Contamination of Glyphosate Weedkiller in California Wine
100% of wine tested showed positive results for Glyphosate weedkiller

Kicking off a news release from the anti-GM group Moms Across America, these headers were backed by data from an analysis of glyphosate (the active ingredient of Roundup, an herbicide that is used with genetically modified, glyphosate-resistant crops, as well as many, many other applications):

The Moms Across America study found glyphosate at:

18.74 ppb from a 2013 Cabernet Sauvignon from a conventional, chemically farmed vineyard. The lowest level was from a biodynamic and organic vineyard, 2013 Syrah, which has never been sprayed according to the owner, with a level of .659 ppb. An organic wine from 2012 mixed red wine grapes had 0.913 ppb of glyphosate.

Yes, those measurements are in parts per billion. To give some reference, the National Environmental Services Center at West Virginia University says a ppb is, “like adding a pinch of salt to a 10 ton bag of potato chips.” But according to Moms Across America founder Zen Honeycutt, for glyphosate even those trace levels are enough to cause harm. “It has to stop now,” she said. “It is poisoning America and destroying future of this great country. If we don’t face up to the overall contamination from glyphosate, we can’t change it.”

On the other hand most science advocates and toxicologists argue that the dose makes the poison. How could such small amounts of any chemical cause this kind of harm, in the short or long term?

One issue with these studies is that Moms Across America admits that the data was never intended to be part of a scientific study. Another issue lies with the use of biomonitoring data.

Getting small with biomonitoring

Biomonitoring is a relatively new way to very precisely detect and measure trace amounts of just about any chemical you’d want to detect and measure. It involves measuring levels of a chemical, or metabolites of that chemical, in human blood, urine and tissues. Today’s technology can now determine existence of chemicals in very, very small levels. And there are two ways to interpret those very small levels—the one, taken by Moms Across America, the Natural Resources Defense Council and other advocacy groups, is to warn that any amount of a chemical is dangerous. Another way is to look at a dosage response curve, as well as exposure to determine the actual danger of a chemical. Comparing a dose curve to a chemical’s lethality (measured as a LD50, or the dose at which half of a population of test animals dies) could give a picture of a chemical’s potential for harm. The larger the LD50, the less likely a miniscule dose of that chemical will cause harm. Glyphosate’s LD50, by the way, is very, very high—slotting slightly safer than baking soda and table salt on the toxicity chart.

Some scientific study data

The largest (and longest) biomonitoring study was the Farm Family Exposure Study, headed by researchers at the University of Minnesota. The researchers studied 95 farm families in Minnesota and South Carolina, who had to apply glyphosate, chlorpyrifos or 2,4-D to their farms. They also had to submit urine samples, which were measured by methods that could detect chemicals down to 1 ppb.

Of the three pesticides, glyphosate had the lowest concentrations found in urine, with an average concentration of 3 ppb. One farmer had a urine concentration of 233 ppb, which was due to not following basic application precautions—he didn’t wear gloves, wasn’t in an enclosed cab, was exposed to a spill, and smoked during the application. But to put that 3 ppb in perspective, the EPA reference dose is a concentration 30,000 times higher. A reference dose is the amount of “daily oral exposure to the human population, including sensitive subgroups such as children, that is not likely to cause harmful effects during a lifetime,” according the EPA.

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To compare that to the Moms Across America wine/glyphosate report, “You would have to drink 2,500 glasses of wine a day for 70 years to reach the EPA’s level of concern,” Gladys Horiuchi, spokeswoman for The Wine Institute of San Francisco, told the Napa Valley Register. “We are talking about minuscule, trace amounts.”

These are just comparisons to the EPA reference, which adds a buffer of safety about 10 times that of a dose that could really start to cause harm. Taking the buffer into account, the amount of wine you’d have to drink to cause harm would be 25,000 glasses a day. For 70 years. With that level of consumption, other health issues would probably arise before glyphosate poisoning.

Biomonitoring data has a lot of caveats. Programs like the US Centers for Disease Control and Prevention’s National Biomonitoring Program use the data to:

  • Determine which chemicals are getting into people’s bodies and how much of those chemicals are in blood, urine, breast milk, and saliva.
  • Monitor the number of people who have levels of a chemical above a known toxicity level (e.g., blood lead levels).
  • Track exposure trends and impacts of public health programs.

While biomonitoring data have resulted in changing recommended exposure levels of certain chemicals, determining the dangerous exposure level of a new chemical, and reaffirmed some existing regulations, it does not mean that any exposure level is automatically dangerous.

The CDC program and others look at a wide range of chemicals every two years to determine exposure and potential public health problems. The chemicals scanned include pesticides, herbicides like glyphosate, and other chemicals that have recently become fodder for scare tactics—PBA and other phthalates, the so-called “endocrine disruptors” for their perceived ability to muck with human hormones and nerve cells, and those that might cause “epigenetic events,” changes in gene regulation that might persist through generations. However, as Genetic Literacy Project Executive Director Jon Entine observed in Forbes:

BPA, phthalates and dozens of other common chemicals every day; and yes, they show up in our urine. It’s estimated that more than 160 chemicals can be detected in human urine, many of which are potentially dangerous if consumed at high enough doses over a long enough period of time. However, our liver regularly detoxifies chemicals from the environment and food, which is why we don’t keel over from drinking coffee, which has dozens of “killer” chemicals.

Just because detectable levels are now down to 1 ppb (compared to 10 ppb 25 years ago), does not mean that those now-discoverable lower thresholds are harmful. Different chemicals have different harmful doses, and it’s now a challenge for public health agencies to keep up with chemical innovation.

The European Commission wrote as it began efforts to integrate biomonitoring in its (and member countries’) environmental and health plans:

Biomonitoring is not an automatic instrument, which can be considered in isolation, but has to be integrated with environmental monitoring, toxicological and eco-toxicological data and especially with considerations related to analytical epidemiology.

The devil remains with the dosage.

Andrew Porterfield is a writer, editor and communications consultant for academic institutions, companies and nonprofits in the life sciences. He is based in Camarillo, California. Follow @AMPorterfield on Twitter.

18 thoughts on “Glyphosate found in 100% of wines tested in California–Reason for concern?”

  1. People are very bad at understanding risk. We are scared to fly in a plane which is very safe but feel very safe driving down the road which is relatively unsafe. We fear things we can’t control but don’t fear things we can control regardless of the actual risk.

    Humans also come with an evolutionarily adaptive disgust metaphor that provides us with a way to categorize things from a visceral level. GMO’s and chemicals are psychologically disgusting. It has nothing to do with actual harm but a feeling inside.

    • For me it has to do with actual harm, and so i do not fit into your categorization. Those people who may have experience some so-called “chemophobia” (a false propaganda word) against PCBs in the 1930s to 1970s would have avoided them even though Monsanto was saying it’s fine, it’s fine, and thereby avoided some of the harms caused by these chemicals. Others who didn’t even know they were exposed, by the way, also got extreme levels of harm including death from these chemicals, but that’s because they didn’t know that they were being exposed when PCBs were dumped into rivers and soil. Anyway, i have a very clear understanding of chemistry and biology, and i have a personal policy of limiting exposure to synthetic chemicals (as well as some natural chemicals that seem potentially harmful, for i know that “natural” is a fuzzy category)…. in short, avoiding exposure is not a psychological flaw in human beings. It’s more of a good trait for survival.

      • Let me see if I follow you: the Chevrolet Corvair was unsafe although Chevrolet said it was safe. Therefore all Chevrolets built since are also unsafe… Sounds pretty retarded to me.

        • I guess you don’t understand basic human communication, then. I used PCBs as one example of a case where a chemical was said to be safe but was actually known to be harmful by those who sold it. People who avoided the chemical on principle of not exposing themselves unduly to the products of the chemical industry fared better than those who trusted the official statements. And from history i learn and draw generalizations. That’s what intelligent people do.

          • Generalisations are not good they’re bad though I’m glad you admit to this.

            Thalidomide was a tested and approved drug that had unforeseen side effects, possibly one out of several thousand actives.
            Logically……therefore YOU would never endorse, for you or your loved ones, the use of ANY drug, medicine or pharmaceutical because of thalidomide then??

          • Hmmm, lets put Chevrolet Corvair and car into everywhere you write PCBs and chemical:

            “I used CHEVROLET CORVAIR as one example of a case where a CAR was said to be safe but was actually known to be harmful by those who sold it. People who avoided the CAR on principle of not exposing themselves unduly to the products of the CAR industry fared better than those who trusted the official statements. And from history I learn and draw generalizations.”

            Still sounds retarded to me. So based on the 50 dead Germans who were killed by organic bean sprouts recently, you will generalize and never “unduly” expose yourself to organic food, right?

          • Don’t care that it sound “retarded” to you to learn from history and to see how industry has operated in the past. Thing is, if a particular company was intentionally negligent and tried to cover up dangers of a particular design flaw, then that company would be more suspect for future such violations. Car manufacturers do in fact go under because of such issues, but Monsanto for instance was able to kill thousands of people through gross malfeasance and hiding of dangers, and then go on to make a chemical that is in 90% of the US food supply. How’s that ok?

  2. I am less worried about the 18.74 ppb glyphosate than the 120,000,000 ppb of ethanol. There is a proven link between alcohol consumption and several types of cancer so if Moms Across America are worried about poison they have focussed on the wrong chemical.

    • We should learn from History. The good old days.
      The ancient Egyptians used Red Wine as a fungicide on stored grain and the Romans used salt in huge doses as a herbicide on roads and infrastructure, oh for the old days!
      Wait a minute though………..both salt and Alcohol are classed as carcinogens by the IARC.
      Still as long as they’re not made by Monsanto that’s the really important bit though.

  3. The issue here is not that the small-ish levels in the wine is going to be dangerous, for it’s far less glyphosate than people get from a typical diet that includes any soy, wheat, corn, cottonseed oil, canola oil, beet sugar and other Roundup Ready crops, and even wheat, oats, legumes, and other crops that are desiccated by glyphosate. It’s the fact that it’s in the wines at all that is disturbing on a level as an indicator of the ubiquitous use of this chemical. It’s sprayed around mature vines in many vineyards. It’s more disturbing that it’s present even in nominally organic wines. I wonder how that is.

  4. Porterfield states “These are just comparisons to the EPA reference, which adds a buffer of safety about 10 times that of a dose that could really start to cause harm.” This statement is inaccurate and the “safety buffer” is even greater than expressed. Porterfield is referring to the EPA defined Reference Dose (RfD). The RfD is derived mostly from 90-day to 2-year daily feeding studies wherein a dosage causing no observable adverse effect compared to no-dose control animals is derived. The No Observable Adverse Effect Level (NOAEL) is then divided by a factor of 100 (not 10) to derive the RfD. If EPA is concerned that the database suggests a chemical causes more harm to infants and children than adults, has special harm to pregnant/nursing mothers, has tested positive for adverse effects on endocrine physiology, or is likely to be carcinogenic, then an extra 10 fold ‘safety factor’ is deployed to derive a Population Adjusted Dose (PAD) that effectively allows a 1000 fold buffer to the dose NOT causing any measurable adverse effect (compared to the control no-dose group). So, the 25,000 glasses of wine become 250,000 glasses of wine. Drink up and enjoy life.
    (BTW, the EPA is very transparent about how they derive the RfD for pesticides and deploy it in their risk characterizations. They publish Registration Eligibility Decisions that summarize the results of the various required tests, how the RfD is derived, what exposure is expected, and thus what level of risk is most likely to occur. EPA then lets you know in those documents whether their level of concern (LOC) is crossed. All details for every registered product can be accessed by using ‘EPA’s Pesticide Chemical Search’ website. Just pop the phrase into GOOGLE and the top hit should be the link to the website.)

  5. Nobody talks about, or tests the cocktails? Is it just too hard with a possible 160 toxins? Or are we just resigned to putting up continually rising cancer levels?

  6. The wine samples were analyzed by The MIL, Inc. lab in St. Louis, MO using an Enzyme Linked Immunoassay (ELISA). The report of ppb levels to 4 significant figures is indicative of a very non-sophisticated laboratory operation. ELISA is very susceptible to false positives for trace level compounds in complex matrices and you can see in the report that some samples had to be diluted to reduce background interference typical with ELISA. There were no spiking and recovery studies done to demonstrate the suitability of this analytical method in measuring trace levels of glyphosate in wine and there were no confirmatory analyses conducted using alternate and more specific analytical methodologies such as LC-MS or GC-MS. Personally, I think these numbers are completely meaningless aside from being ridiculously trivial.

  7. Where else are we getting glycophosphate and at what level? Add all of the sources of glycophosphate and then tell me the amount in wine is okay.

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