A Fishy Attempt To Link Glyphosate and Celiac Disease

Celiac is real.  The glyphosate link isn't

Stephanie Seneff (a computer scientist at MIT),  and Anthony Samsel (a retired consultant), have recently been attempting to link the use of the herbicide glyphosate to a long list of modern maladies. Their latest such attempt to is Celiac disease.  The overall argument for the glyphosate/Celiac link has already been quite thoroughly debunked by a Celiac expert, but there is one other good reason to dismiss the "link" which I would like to describe.  It has to do with a "Fishy" study about glyphosate and fish which is so flawed that it should never have been published in the first place.  That is why it can't be used to support this chemical/disease link.

The Fishy Study

Samsel and Seneff cite a publication by Indian scientists from 2009 (Senapati et al). In that study, ugly effects were observed in the digestive track of the fish that were exposed to water containing a glyphosate-based herbicide.  Such a finding would be surprising, because for decades, glyphosate has been a preferred method of weed control in aquatic settings, specifically because it has unusually low toxicity to fish and other aquatic organisms.  Glyphosate is particularly valued by the people who are trying to control invasive weeds in wetlands, lakes etc. as described here for CA, WA and FL.  They spray it on the part of the weed that is above the water because that is the only way it is effective, but obviously some glyphosate gets into the water.  Still, this use has long been considered to be safe for fish.  Did this paper document a previously unrecognized issue?

In their analysis of the Indian fish study, Samsel and Seneff concluded that the effects observed on the fish digestive systems were "highly reminiscent of Celiac disease." To me, the effects sounded much more reminiscent of surfactants.  Fish are very sensitive to those.

When I read the Senapati article, it quickly became obvious that this was indeed the problem.  These researchers specifically stated that they used a commercial formulation of glyphosate manufactured in India called Excel Mera-71.  A quick web search shows that Mera-71 is a formulation made for terrestrial, not aquatic use. The manufacturer describes it as containing glyphosate and "a blend of non-ionic and cationic surfactants." At least in the US, products registered for use on weeds growing in water do not contain surfactants because surfactants are well known to injure fish. There was no surfactant control, so the reviewers of the Senapati study should never have let them conclude that the effects were from exposure to glyphosate. It is much more likely that the fish were injured by the surfactants.

Fish Abuse

NOOOO! Not another water change!

There were other experimental design problems with the Senapati study.  They chose to put the fish into water containing 4mg/L of glyphosate.  To achieve that sort of concentration by spraying weeds in even shallow water would have required spraying the weeds above the water at many times the maximum rate allowed. (Here is an EPA label for a glyphosate product for use on weeds in water - AquaMaster). Then, to make matters worse, the water in which the fish were being kept was replaced every other day for 45 days with a fresh solution of 4 mg/L glyphosate along with the inappropriate surfactants.  That would not correspond to any imaginable use-scenario in the real world. So basically, Senapati et al abused several poor fish for more than six weeks to demonstrate what was already well known - surfactants hurt fish.  The only thing remarkable about the study is that the fish even survived. Glyphosate is still a good option for the control of aquatic weeds.  No, it does not cause Celiac.

Some Additional Thoughts About The Scientific Process

This study was a "literature-only" review which involved no actual experimentation.  That can be ok.  The literature is there to be the subject of scholarship.  On her own web page Seneff explains that she places her work in the "open access journal," Entropy, because it is "willing to publish novel hypotheses," and because  "the papers are subjected to rigorous review by experts who were not beholden to industry influence."  That can be ok too as the making of hypotheses is the starting point for the scientific method and unbiased reviews are important for science.  However, if one is going to attempt to do science this way you can't assume that every paper you find actually shows what it claims to show, even if it's what you would like it to show.   If these authors wish to review papers this far outside of their own discipline and training, they would do well to confer with people more familiar with these topics. I would be happy to recommend such resources for future publications.

In science, even when research is published in a "peer reviewed" journal, that does not finish the vetting process.  Particularly if some new finding challenges previously accepted ideas, the next stage is critical.  Does the work hold up to scrutiny by the broader scientific community?  Can the results be repeated by others?  The Senapati and Samsel /Seneff papers fail to pass these tests.  Researchers that are really trying to understand conditions like Celiac disease will continue to look at other, more likely causes.  Unfortunately, in the extensive, anti-technology sector of the internet, this new "link" will likely live on and joint the list of other myths about food and agriculture.



Celiac micrograph image from Wikimedia Commons
Unhappy Fish Image from Kiler129's Photostream

You are welcome to comment here and/or to email me at savage.sd@gmail.com

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Thoughts About Norm Borlaug on the 100th Anniversary of His Birth

Norman Borlaug would have been 100 years old today.  He has been called "The Man Who Fed The World," and "The Father of The Green Revolution."  Norm Borlaug was the first plant pathologist to be awarded a Nobel Prize (1970) - for contributions to world peace. For all of use who are fellow plant pathologists, his work has been particularly inspiring.

It is a good time to look back at how the challenge of feeding the world population was met during Borlaug's career, because we have a similar challenge ahead of us. The chart below shows global population from 1950 with a projection to 2100.  I've been looking at food production data available from the UN Food and Agriculture Organization (FAOSTAT).  If we look at the half century since FAO started tracking it in 1960,  global population increased by 3.89 billion.  Between 2010 and 2060, global population is projected to rise by another 3.04 billion.

Between 1960 and 2010, production of most crops did manage to keep up with population growth and for many crops there was actually more available per person in 2010 than in 1960.  Living standards also improved in many parts of the world, which meant that people were able to enjoy that per capita increase.  Fertility rates have declined with the education of women combined with improvements in living standards and food security. It is projected that global human population will level off by around 2100 due to these factors.

The increase in food production during Borlaug's era was mostly achieved through increased yield on each acre or hectare grown, not from farming more land.  That was made possible by agronomic improvements,  including the breeding advances that came from the work of Borlaug and many others.

In the graph above, the two bottom, green bars show the global crop area in the window 1960-65 (1.09 billion hectares) and 2005-10 (1.45 billion hectares).  The increase, shown in the red bar, is 362 million hectares. That is an enormous amount of land, but without increased yield, it would have taken nearly 3.1 billion hectares (blue bar) to have provided the amount of food that was available to the world by 2010.  That effectively means that the global farming community, and those that aided it with technologies, advice and expertise, "saved" more than 1.6 billion hectares of land from being converted from a natural state into farmland.  Realistically, there is not that much land which could ever be farmed.

Many of Borlaug's contributions were to the staple food crop - wheat.  Wheat is not a single crop, but a collection of many different types of wheat grown for different kinds of food ranging from hearty breads, to pasta, to crackers, to flat breads to soft noodles. By the end of this 50 year window, the world's wheat farmers were producing 2.69 times as much wheat as in 1960. However, 97% of that increase (green part of the bar) was enabled by higher yields.  Only 10 million more hectares were being grown. That meant that the world could continue to have enough wheat without the need for adding 346 million more wheat hectares.  That is the legacy of Borlaug and the other participants in the Green Revolution.

The story with rice is almost as positive.  In 2005-10, humanity had access to 2.9 times as much rice as in 1960-65, and 83% of the increase was attributable to yield with 39 million new hectares added.  That meant that there were 187 million hectares which did not need to be added to the rice production base.

The story behind these higher yields is complex and varies across geographies. The details of how we might continue this sort of progress through 2060 are also complex and will involve new challenges such as climate change.  Even so, on this important anniversary it is fitting to look back at the remarkable accomplishments of the past to find inspiration for the challenges of the future.  Lets hope that at the 150th anniversary of Norm Borlaug's birth people will once again be able to look back and tell this kind of story.  A story about humanity continuing to be fed, but without having had to add much if any new farmed land.  Even into his 90s, Borlaug continued to be an articulate proponent for letting farmers use the full toolbox of technologies, including biotechnology, to pursue such goals.  Now its up to us to continue to make that case.

Image of the Norman Borlaug Congressional Medal from Wikimedia Commons.  Graphs mine based on FAO and Geohive data.

You are welcome to comment here and/or to email me at savage.sd@gmail.com

I tweet about new posts @grapedoc

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Our Farmers Get An A+ For Low Pesticide Residues

Last week, the USDA released its annual Pesticide Data Program (PDP) report about pesticide residues on food.  This release comes from extensive sampling of crops entering the market during 2012.

Here is the official, summary statement from the USDA:

"The Pesticide Data Program provides reliable data through rigorous sampling that helps assure consumers that the produce they feed their families is safe."  

And the official statement from the EPA:

"The newest data from the PDP program confirm that pesticide residues in food do not pose a safety concern for Americans."

For the agricultural community, particularly those involved in the production of fruits and vegetables, this USDA program is sort of a report card - like a grade to you get for a "group project" of epic proportions.  Imagine you are back in school. You are part of a huge group of fellow students only a few of whom you know, and many of whom are in different countries around the world. The grade that you will receive is based on the work of a random sub-set of these students. All that you can do is try your best and hope that everyone else does the same.  Under those circumstances, it would be a great relief to find that your entire group did such a good job that their collective score was 99.5%!  That is an A+ by any standard. That's what just happened again for the farmers who produce our food. This isn't the first time. There is a great website that allows you to visualize the data from all the years the PDP has been conducted.

What The Data Says

The pesticides used in modern agriculture are now dominated by products which are far less hazardous than what most people imagine.  The use of all pesticide products is highly regulated, and in order to use them, farmers have to qualify for a license and must take continuing coursework to maintain their right to use them.  They are required to adhere to the detailed label restrictions for every product in terms of how much can be used and how long before harvest.  Those label rules are based on an elaborate risk analysis that the EPA performs for each product.  That analysis reflects information about toxicology, metabolism and environmental fate which is generated for each product at a cost of many millions of dollars.  Based on all that information, the EPA sets a "tolerance" for each product specific to each crop on which it is allowed.  If the pesticide residue level on a crop is at or below the tolerance, it has something like a 100-fold safety margin for consumption by us, the consumers.

 So what matters with pesticide residues is not simply whether or not they can be detected with the enormously sensitive laboratory methods available today, but exactly which chemicals are involved and at what levels relative to the tolerances.

So how did farmers do for the 2012 crop when it comes to residues relative to tolerances?  They did great!  Of the 11,893 food samples tested, 99.47% had no chemical residues above tolerance.  47.4% had no detectable residues at all, but for the rest the levels were often far below the tolerances.

Most crops tested in 2012 had NO samples with over-tolerance residues.  Those included apple juice, avocado, baby food made from apple sauce, carrots, peaches or peas, bananas, butter, cantaloupe, cauliflower, mushrooms, onion, orange juice, papaya, plums, tangerines, and wheat grain.

I hate to be like the parent who sees a report card with all As and one B+ and focuses on the B+, but it is interesting to see what was going on with the half of one percent, or 63 of nearly 12 thousand samples that had residues which were over tolerance.  There was only one sweet pepper sample imported from Spain that had such a residue. There were two samples of summer squash from the US with residues slightly above the tolerance. There were four samples of winter squash, two from the US and 2 from Mexico, which had higher than tolerance residues.

The only crops with any significant number of above-tolerance detections were snap peas (32 from among 743 samples) and cherry tomatoes (24 from among 744 samples).  However, even these unusual incidences were not enough above tolerance to be of major concern. For the snap peas, 97% of the samples with those higher detections were imported either from Guatemala, Peru or Mexico.  For the cherry tomatoes, 83% of the above-tolerance samples came from Mexico.   If the "group project" was divided into a US farmers team and a importers team, their respective "scores" would be 99.88% and 98.76% - different, but both still A+ grades.

For just over 4% of the 2012 samples, very low levels of pesticide residues were detected for materials that didn't have a specific tolerance for that crop.  This can happen because of spray drift or contact with equipment after harvest.  The levels were too minor to be of concern to the regulators.  Similar, low level residues are found on organic crops.  In a recent pesticide residue study in Canada, synthetic pesticide residues were detected on more than 40% of organic produce.  Similar results have been seen for organic in the US in the past. Again, these sorts of very low level detections for organic or non-organic crops reflect mainly the sensitivity of analytical lab methods - not any real risk to consumers.

As in previous years, this survey documents the fact that our food supply is extremely safe, and that no one should hesitate to enjoy it based on worries about pesticide exposure.

Rain On The Parade Is Predicted

Unfortunately, we can expect that once again, the Environmental Working Group will take this transparent source of public information and intentionally misconstrue it to generate their "dirty dozen list."   They ignore the transparent public data about which chemicals are found, at what levels, and how that relates to the tolerance.   The EWG ignores those critical details, because to do so suits their agenda of scaring people into purchasing organic (They fail to mention the studies showing similar residues on organic).  If things go as usual, much of the press, blogosphere, and organic advocacy community will uncritically re-transmit the EWG's distortions. The effect can be that many innocent consumers will either avoid health-promoting food options, pay a price premium for organic, or feel guilty about not doing so.

That would be sad.  In fact, this new USDA data shows that the diverse collection of farmers who produce our food deserve appreciation for their care in controlling pests in a way which is also safe for us as consumers.  The truth is that consumers deserve to enjoy what those farmers have produced without fear or guilt.

You are welcome to comment here and/or to email me at savage.sd@gmail.com.  I tweet about new posts @grapedoc

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Am I A "Shill For Big Ag?"

Because I blog, speak, and comment in support of various agricultural technologies, I am routinely accused of being a "shill for Big Ag" or for some company which you can probably guess.  They believe that I am somehow paid to say what I say.  If I am a "shill,"  I'm clearly not doing it right.  Either that, or there is in fact no money in the shill business.

When I've met some fellow farming and technology advocates, we often joke about this. "Did you get your Big Ag check yet?  Mine doesn't seem to be coming?" While I'm sure there are people who will never believe this,  in 5 years of advocacy I have never been offered any money, nor do I know of anyone else who has. There is no formal or informal "Shills-R-Us"organization or whatever it is that some people imagine. In actuality, there is a relatively small community of people who choose to defend agriculture and its supporting technologies, and they do so by committing their own time and effort without compensation.

Why do we do this?  I’m sure the there are many reasons, but making money isn’t one of them. In fact, choosing to speak out on the hot-button issues around food and farming is much more likely to detract from a career.  Cami Ryan, a social scientist who both advocates for agriculture and studies the public debate about it, has documented the practical reality that when University faculty members take time to advocate, it only detracts from time spent on the criteria by which their careers are advanced (publications, grants…).  I’m very glad some academics are still willing to do it.  I’m also very glad that there are members of the farming community willing to take time from their busy lives to speak out.  Besides, anyone who actually knows scientists or farmers realizes that they are fiercely independent people who would not like anyone telling them what to think or say.

I'm a somewhat unusual member of this advocacy community in that I'm very much an industry insider.  In the past I've worked for a large technology company, DuPont, and also for a small, start-up technology company, Mycogen.  Since 1996 I've been an independent consultant working for all sorts of different companies in the agricultural technology space - pretty much all of them at one time or another.  Over those years I've done projects on a wide range of technology, marketing and sustainability questions, but none of that paid work has had anything to do with the advocacy work I've been doing since 2009.  In fact, the substantial amount of time I've spent on blogging etc has had the effect of reducing my consulting income. My writing has also compromised my consulting business to some degree. My visibility in a controversial and acrimonious debate is problematic from the perspective of some of my clients.  My writing has led to some speaking engagements, but when I do get an honorarium for those, it does not begin to cover the lost potential income.

One major reason that I continue to spend time blogging, and the reason I shrug-off the shill accusations, is that I feel an obligation to share the perspective I've gained specifically because of being an industry insider for more than 35 years. The industry and farming communities I know are not anything like the picture often presented by critics of agriculture. After years of listening to unfair demonization of the creative, thoughtful, ethical people in agricultural industries, I felt compelled to try telling their side of the story.  I've had the privilege to know and work with many people in industry and academia who have developed key tools for farmers.  I've had the privilege to sit down and talk about technology issues with diverse groups of farmers.  I've spent quite a bit of time with a variety of regulators who are charged with assessing risk in these fields.  What I've seen is that people associated with farming are not at all like what appears in the dismissive and or conspiratorial narratives that abound.  Yes, I'm an industry insider, and I'm proud to be a part of that sector.  I don't blame anyone for taking my potential bias into consideration, as long as they will still consider logic and facts.

Another reason that I continue to blog is that I'm saddened to see so many people who view their food supply with fear and/or guilt. Those of us who live in the rich world have access to a remarkable range of delicious, safe, nutritious, food options.  However, we are inundated with voices telling us otherwise and giving us inappropriate and sometimes outright terrible advice about food.  One of my goals is to give consumers some background to use to better sift through the onslaught of often confusing and misleading "information" that abounds.

The final reason I continue to advocate for certain technologies and for the right of farmers to use them is that I believe it matters.  There is an important ethical dimension, not just to what technologies we use, but also to those we do not use or do not develop.  There are significant ramifications for the future of the food supply in the rich world, but vastly more important ramifications for those outside of the rich nations.  I'm not saying that technology X or Y will "feed the world." It's never that simple. But the truth is that farmers are the only ones who will feed the world, so it's time to pay attention to the tools they find most useful for doing so.

I know that I am unlikely to influence almost anyone who thinks that I do this because I'm a "shill."  My hope is to offer an alternative perspective for those who are still open-minded enough to weigh facts, data, and personal experiences.



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As always, you are welcome to comment here and/or to email me at savage.sd@gmail.com.  I tweet about new posts @grapedoc

Money image modified from Andrew Magill's Photostream

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School Science Project Gone Bad

The above video is making the rounds on social media in which a young girl named Elise describes her science project. Elise wants to sprout a sweet potato plant from a conventional sweet potato she purchased at her local grocery store, but it doesn’t work.  Her grocer gives her the explanation that the sweet potato was probably treated with a sprout inhibitor chemical called Sprout Nip®.  She tries again with an organic sweet potato, which sprouts much better.  Elise finds some information about the mentioned inhibitor, and then concludes that this is a good reason to buy organic.  The little girl is articulate and convincing, but in fact she is straight up wrongabout the sweet potatoes. She also lacks some important perspective on the role of sprout inhibition in the sustainability of the food supply.  

It’s a good example of how social media can be a misleading source of "information" about food and agriculture.

I heard about this video from a blogging friend named Amanda who does some great posting as The Farmer's Daughter USA. We decided to work together to frame a response for both of our readerships. 

I've never really worked on projects involving sweet potatoes, but it was an easy matter to determine whether Sprout Nip(r) is a sprout inhibitor used for that crop as the grocer told the student.  The EPA approved labels for crop protection products are all available on-line.  The label for Sprout Nip does not list sweet potatoes among the approved uses.  Unlike the pharmaceutical industry, where a doctor can prescribe a drug for something other than its original use, it is strictly illegal in agriculture to use a product unless it has been approved by the EPA for a specific crop and use scenario.  

So the grocer mislead the student, but was he was just wrong about the particular chemical?  Again, it wasn't hard to find a comprehensive document from North Carolina State University about post-harvest handling of sweet potatoes.  That document clearly states that, "chemical sprout inhibitors are not used in sweet potatoes because proper temperature control inhibits sprouting."  I also checked with one of the expert authors of that document, and she confirmed that there is no need for sprout inhibitors if sweet potatoes are properly "cured" by holding them at the right conditions soon after harvest.  So the difference the student found between the conventional and organic sweet potatoes had nothing to do with a chemical sprout inhibition treatment - neither the conventional or organic sweet potato had been treated with one.  It is more than likely that the reason there were differences in sweet potato sprouting was merely due to their ages and how these were stored.

In any case, the "good reason to buy organic" conclusion from this "experiment" was simply wrong.  I don't blame the student, but rather the adults who "helped her" reach such a conclusion.  I hope little Elise has a continuing interest in science and eventually learns about how to design experiments with appropriate controls and sample sizes, and learns about not jumping to ideological conclusions that your data can't support.

The other problem is that this video fails to provide any perspective on the important role of sprout inhibitors for the sustainable production of the crops where they are actually used.   Recently, a number of food commentators have rightly been emphasizing the importance of reducing food waste, not just producing more food.  What few acknowledge is that there have been people working hard to do exactly that for several decades.  Sprout inhibitors are one prime example of waste reduction.

Why Are Sprout Inhibitors Used On Regular Potatoes?

The sprout inhibitor that Elise describes, chlorpropham, has been an important tool for regular potatoes for nearly 50 years.  It is better known in that industry as CIPC.  Most of the spuds grown around the world are called "fall potatoes" because that is when they are harvested.  For centuries, people have spread out that supply by putting the potatoes into a cool, dry storage facility of some type - originally just a "root cellar" and in recent times large storage facilities that can handle millions of pounds.  If the potatoes are stored at a temperature that is best for quality, they will eventually begin to sprout.  Most consumers have had the experience of potatoes sprouting in their pantry because we generally store them at room temperature.  Without the ability to control sprouting, there would be no way to maintain the consumer and restaurant supply of fresh potatoes for a good part of the year. This is even more of an issue for the increasingly popular colored potato varieties. The sprouts are also rather toxic. For the part of the crop being held in storage longer, there would be substantial waste because it isn't always possible to predict when a given lot will start sprouting.  

By the way, organic potatoes have to be treated with a sprout inhibitor as well.  Currently their best option is clove oil.  Because it is less effective, it has to be applied as many as 5-8 times during the storage season.

Longer term storage is also very important for the substantial part of the potato crop that is processed to make frozen fries and other products.  Without the ability to prevent sprouting, it would not be possible to spread processing of the fall crop over most of the year.  That would mean needing to build a great deal more processing capacity and then to have it sit idle for many months.  The processed potatoes would also have to spend longer in low temperature storage.  All of these things would increase the capital cost, energy requirements, and ultimately the consumer cost.  In addition, storing potatoes at low temperatures will increase the sweetness of the potatoes and this is undesirable from a taste standpoint. That is the reason why, one should never store their potatoes in a refrigerator. 

Is It Safe?

As for whether CIPC is safe, as an older product in use for over 50 years, it has been through multiple cycles of close scrutiny by the EPA and regulatory agencies around the world.  You can read a detailed risk assessment from the EPA, which determined that if potatoes had residues below a new, conservative threshold of 30ppm (parts per million) they would be safe for consumers.  Potatoes have been tested in the USDA's Pesticide Detection Program (PDP) 9 times since 1992, and none of the detected Chlorpropham residues were even close to that level.  Some export market countries have set lower thresholds (e.g. 10ppm for the EU), and a few of the historical detections have been at that level.  

Thus, there has been interest for some time in finding an alternative way to prevent sprouting.  There is a very good article about all this in Spudman magazine (seriously - there is a potato trade journal by that name - I used to have a subscription). Nevertheless, many grocery chains and restaurant chains are actively looking to drastically reduce the amount of CIPC on the potatoes they buy.

A Next Generation Sprout Inhibitor

A few years ago, a scientist named Dr. Rick Knowles at Washington State University captured natural, volatile chemicals that came from potatoes.  He analyzed them and reapplied several of the products back to potatoes. He found that certain unsaturated ketones and aldehydes caused sprout suppression.  Many of these chemicals are known, food-grade flavoring agents. One of those was subsequently licensed and commercially developed by AMVAC under the trade name SmartBlock®.  It was approved for sale in 2013, and is already getting lots of traction in the industry.  Growers are finding it to be a good replacement for CIPC.  In Europe (where CIPC is also under some pressure), it may be approved for use as well.  It is more expensive than CIPC, but probably not enough so for consumers to see any noticeable price change to the cost of raw potatoes, French fries or chips.

SmartBlock(r) is based on a "natural product," that is to say that it's active ingredient, 3-decen-2-one, is found in foods such as yogurt, tuna fish, soy, mushrooms etc.  Having that "natural" status is certainly helpful for marketing, but in fact that does not automatically mean anything about its relative safety.  There are natural products that are extremely nasty - this just does not happen to be one.  It is in fact on the GRAS list: Generally Regarded as Safe, which is a list maintained by the Food and Drug Administration (FDA) for use as a direct food additive in things like baked goods, non-alcoholic beverages etc.

The actual importance of being a naturally occurring compound is that there is a much lower cost pathway for registration for such products through the EPA (as a Biopesticides).  The requirement is that the material passes Tier I toxicity testing with flying colors. That is important because even the entire global potato storage market would not be a big enough market to justify the huge investment it takes to commercialize a new, synthetic product.  

It seems likely that SmartBlock may replace a fair amount of the use of CIPC on potatoes, but it will take time to learn how best to use it to prevent food waste.  The company is trying to get it approved for organic potatoes as well, but whether it will be allowed for that use is currently unclear.  Even though one can find the chemical in nature, it is not at all practical to get enough of it by extracting it from those sources such as yogurt or tuna fish!  SmartBlock is made synthetically, but it is the identical chemical to what is found in natural sources and is 98% pure.    This is not a situation like vanilla extract where the artificial vanilla only represents one chemical in a complex mixture.  It’s also not like some vitamins which are less bio-available from synthetic sources.  Even so, the rules for organic are based on a philosophical preference for "natural," not on chemistry or safety alone.  

Elise’s appealing little video, which has gone viral on a lot of organic websites, is a classic example of how the "information age" can become the "disinformation age." There is actually a ton of relevant information available on the internet, but when people lack proper background, and when they come to a question with a pre-existing bias, it is all too easy to just find what you want or expect to find.  That is what happened in this case, and so this young student ends up being an effective transmitter of "information" that is simply wrong. 

You are welcome to comment here and/or to write me at savage.sd@gmail.com

Sprouting potato close-up from wikimedia

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Why You Probably Don't Know That Pesticides Have Changed

Note how grape pesticide use has shifted almost entirely to the EPA
categories IV (practically non-toxic), and III (slightly toxic)

In my last post I gave an example of how much safer pesticides have become over time.  That would come as news to most people because they have a negative, out-dated and stereotyped image of pesticides.  I think there are three reasons for this:

1. Very few people have any role in the control of agricultural pests
2. There is a widespread, convenient fiction that organic farming means no pesticides
3. The unlikely "team" that has driven change in pesticides has, for various reasons, failed to communicate their success

1. Who Controls Crop Pests? Probably Not You

If you live in the rich world and are involved in crop production, you are part of a tiny minority of highly efficient producers. Because of this, there are very few people who have observed the changes in the nature of pesticides over time or who are familiar with the current portfolio of options.  I follow a number of farm press publications and blogs, and the discussion of pesticides there is completely different than in any mainstream source. Those who choose to play a role as commentators on agriculture should take the time to be well informed on modern pesticide use and safety.

2. The Convenient, "No Pesticides" Fiction

The production of organic crops definitely involves the use of pesticides. In many cases it requires more frequent applications and/or higher use-rates per acre than for conventional. The pesticides organic farmers are allowed to use come from a list deemed by committee as being "natural," but they are still pesticides and they are not necessarily safer for us or for the environment than options available to other farmers. Natural does not automatically mean safe, that is why natural options also have to go through EPA registration. There are quite a few pesticides that are widely used by both kinds of farmers.  These facts are not broadly understood.

Most consumers have the impression that choosing organic means avoiding pesticides, and the broader organic marketing chain and advocacy wing is often happy to promote this misconception.  At a farmer's market one often sees signs saying, "no sprays," or "pesticide free," statements that are rarely true. Various promoters and marketers of organic often argue that consumers should choose organic "to avoid pesticide residues" even though choosing organic actually means you know less about what residues are likely to be present because none of our residue monitoring efforts look for some of the materials most commonly sprayed on organic crops (e.g. copper fungicides, biocontrol agents, Bt toxins...).

At a mainstream grocery store I recently saw a sign over the organic produce display saying "grown without chemical fertilizers or pesticides," as if there were some category of physical matter which isn't a chemical.  Even defenders GMO crops are often guilty of saying that a Bt crop "reduces the use of pesticides" when, in fact, it is simply a different means of delivering a pesticide - another very safe one, but still a pesticide. The consumer needs to know if there is any pesticide residue of concern on a given food. Year after year, an extensive USDA survey of pesticide residues on food in commercial channels  show levels that are too low to be of concern. Consumers have no reason to hesitate to consume the domestic or imported conventional food supply in the US. Unfortunately this analysis is routinely distorted by the Environmental Working Group to promote organic as a means of "avoiding pesticide residues."  Recent data from Canada shows that there are frequently pesticide residues on organic produce there.  Again, the question is whether the levels are high enough to matter.

3. The "Team Effort" You Never Hear About That Made Pesticides Safer

As a 37-year participant in various parts of the process of changing the nature of pesticides, I've seen an unlikely collection of entities, each of which should take some of the credit for the progress that has been made.  For each I'll briefly describe their contribution(s) and also speculate on why you probably don't know about it or appreciate it.

• The Environmental Movement:  becoming visible after the publication of Rachel Carson's "Silent Spring" in 1962, a broad coalition of NGOs, politicians and academics drove the awareness and impetus for the creation of regulatory bodies such as the EPA (est. 1970) which began to regulate pesticides. In a variety of ways these groups have continued to be an important voice that puts pressure on regulators to deal with additional issues as they arise through advances in the sciences of human and environmental toxicology. However, you won't hear these groups talking about how much things have improved. They tend to focus on the next issue rather than on past progress, even if they could take some real credit along with the rest of the "team." 

• The Major AgroChemical Companies:  These players have been investing hundreds of billions of dollars over decades to discover, evaluate, and commercialize new pesticide options.  Their search has been for products that work better, which are more selective, and which can meet ever more sophisticated health and environmental standards. Without this investment, between pest resistance development, new pests and regulatory constraints, farmers would never have been able to accomplish the sort of productivity gains that have been seen. These players are actually constrained by the EPA from talking about new products as being safer than the older ones. They also usually have a mixed portfolio of newer and older products.  Besides, in an anti-business climate their messaging is typically ignored.

• Government Regulators:  If you step back and look at what agencies like the US EPA have accomplished over the decades, it is rather impressive.  On the whole, the EPA has done its job in a way that is science-based and free from excessive political influence.  As is probably the fate of any such regulator, the various "sides" on issues are all going to be unhappy with something about your decisions or bureaucratic procedures.  Honestly, the EPA does not seem to have the skill or orientation for public promotion of what they have achieved (although this summary is pretty good).  In any case the political Right tends to want to get rid of the agency, and the Progressive Left seems to think that they have all been "bought-off."  I have some direct experience with EPA staffers and a window on their process through friends who serve on advisory panels. This system isn't perfect, but it deserves a great deal more respect than it gets.

• Academics and Other Public Research Institutions (University, USDA, EPA, Research Institutes...):  Public, industry, and grower groups have funded basic and applied research  critical to the progress that has been made on understanding toxicology, environmental fate, modes of action, and efficacy of pesticides.  Many chemical leads have come from basic work on natural products. Most biological control ideas emerged from this sector. The integration of pesticides with the many other means of pest control was often researched here. You may not have heard much about this because scientific publications are not designed for the public, but there are some USDA and University publications designed for more general readership. 

• The Public and Private Entities Closest To Farmers:  The farming community is provided with applied research results, technical advice, and logistical support by a range of groups such as State and County Extension Agents, AgChem Retailers, Crop Consultants, experts supported by Grower Organizations and sometimes major purchasers of their crops (other government and university experts overlap in this area as well).  The evaluation and integration of new pest control methods of all types and combinations is greatly aided by this group. They are highly focused on their grower base, so most people would never hear about them.

• Farmers Themselves:  The role of farmers is perhaps the most important because they are the ones who integrate ever changing pests, climate, regulations and pest control options. They also absorb the associated economic risk. The farmers are the ones for whom pests are an ever-present reality. They certainly have economic incentive to limit their pest-related losses, but also economic incentive to do so in a cost effective way. They care about the environment and human health as much as anyone.  Fortunately they have a stream of new options to help them pursue those goals and the willingness to innovate to make them work.  Instead of getting any appreciation for these efforts, farmers are routinely demonized by critics who have not bothered to get an in-depth understanding of their challenges or of the tools they actually use.

Consumers don't have to understand how much pesticides have changed or why in order to get the benefits that come with increased productivity and safety.  However, it wouldn't hurt them to know about this so that they could enjoy the food available to them.

Chemical Free Egg Image from Bob Doran

You are welcome to comment here and/or to email me at savage.sd@gmail.com

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An Example Of How Much Pesticides Have Changed

The pesticides that farmers use to protect their crops have changed a great deal over the last few decades.  While improvement is something we expect from technologies as diverse as pharmaceuticals to electronics, few people are aware of the positive developments in the chemicals used for crop protection.  Dramatic change began with the establishment of the EPA in 1970 which led to the elimination of many problematic, old pesticides.  Also, there has been a steady stream of new product introductions with both safety and efficacy advantages.

To document how pesticides have changed, I decided to download historical information for one of my favorite crops - premium wine grapes. California has had mandatory pesticide use-reporting in place since 1990. The resulting data can provide a window on at least 22 years of this evolution. I chose 5 counties that would represent much of the premium acreage in both the North Coast (Napa, Sonoma, Mendocino - 121,700 acres in 2011) and the Central Coast (Monterey, Santa Barbara - 62,288 acres in 2011).

Grapes have a wide range of pests, including several kinds of insects, mites, nematodes, fungal diseases, and viruses, the vectors of which require control. Weeds are also an issue. Because traditional varieties are highly valued, conventional plant breeding is not an alternative to get around these pest problems. As with other crops, the management of these pests involves much more than just pesticides.  Even so, pesticides will always be necessary tools. Pest control in grapes is important for both yield and quality, and in some cases for the long-term survival of plantings that are very expensive to establish.  As with other crops, control of grape pests also preserves efficient use of other resources such as uniquely suitable land and scarce water, as well as expensive nutrients, fuel and labor.

Fortunately, for reasons I will describe in a subsequent post, the pesticides available to farmers today are both effective and relatively safe - much safer than what they were a few decades ago, and much safer than most people imagine.

The Overall Use-Trend

As you can see in the graph above, overall, pesticide use on grapes (in terms of pounds of active ingredient) has been declining since 1995.  The numbers; however, are rather large compared to other crops - 40 to 100 pounds of active ingredient per acre per year (The recent controversy about pesticide use on Maize nurseries in Kauai was over a 1.9 lb/acre/year use pattern). There is one simple reason that these numbers are so large - sulfur.

There is a fungal disease called Grape Powdery Mildew which infects even under California's dry summer conditions.  Elemental sulfur, applied either as a dust or as a wettable spray, has been the mainstay for control of that disease for centuries. As you can see in the graph to the right, sulfur accounts for most of the very high pesticide load, particularly in the 90s. Sulfur is considered a "natural product" and is thus approved for organic.  In fact it is almost all that an organic grower can use for this disease. It has to be applied frequently and at very high rates. Sulfur is considered relatively safe, but it is a skin and eye irritant which is problematic for vineyard workers.  I've spent lots of time working in vineyards and the sulfur makes that unpleasant. The tendency of the dust to drift is annoying for neighbors of vineyards.

Notice that after 2000, the amount of "other foliar applied" pesticide increases.  Much of this represents modern options for mildew control that have allowed growers to dramatically reduce their overall use of sulfur.



The Non-Sulfur Trends

Taking a closer look at everything that wasn't sulfur, we see that the pounds per acre of other foliar pesticides more than doubled and the soil-applied pounds per acre dropped 4x between 2000 and 2011 (the latest year of data available).  But of course when it comes to pesticides, "pounds" isn't really a very informative measure. Pesticides differ dramatically from one another, particularly with regard to acute toxicity.




The EPA classifies pesticides into four categories based on their toxicity (see an explanation of how this is measured at the end of the post).  Their acute oral toxicity is a major part of that classification:

1. Category I, "highly toxic" materials, Oral ALD50 less than 50 mg/kg                                       
2. Category II, "moderately toxic" materials, Oral ALD50 50 to 500 mg/kg
3. Category III, "slightly toxic" materials, Oral ALD50 500 to 5000 mg/kg
4. Category IV, "practically non-toxic" materials, Oral ALD50 greater than 5000 mg/kg

What About Most People's Image of Pesticides?

When most people hear "pesticide" their mental image is something like the old, highly toxic, organophosphate (OP) insecticides.  The graph at the right looks specifically at what percent of all the pesticide applications (sprays, not pounds) were made with these sorts of products. Note that the classic, Category I OPs were never more than 6% of the sprays and have been under 1% for the last 10 years of data. Even the moderately toxic category II OPs have never represented much of the total spray load. In the last few years they have declined to an all time low.  These products make up an even smaller fraction of the total pounds of pesticides applied (under one percent for all 22 years).  Thus, what most people imagine when they hear "pesticide" is actually a very rare type of product in terms of actual use.

The Changing Product Mix Used on Grapes By EPA Category

The graph above tracks the proportion of non-sulfur pesticides used on these grapes by EPA category.  Even when all the Category I pesticides are included, they have never made up more than a tiny percentage of what is sprayed on grapes. If we had data like this going back to the 60s or 70s there might have been more - but highly toxic products have not been used much in this or most other crops for a long time.

Category II pesticides were a reasonably good part of the mix until recently.  The EPA calls these "Moderately Toxic."  That may sound scary, but many familiar food and beverage chemicals fall into this toxicity range including capsaicin in hot peppers (140mg/kg) and caffeine in coffee (161mg/kg).  Several products used on organic grapes also fall into this category.  Even so, this has been a declining category over time.

The EPA category III products are called "slightly toxic." Very familiar natural products like citric acid, acetic acid, vanillin or even table salt fall in this range. There has been some increase in the use of products in this category.

The category IV products are classified as "practically non-toxic" and this has been the area of most rapid growth since the mid 1990s.  Many of the products that have displaced sulfur use fall into this category.  Many of the products that have replaced the old OPs fall into this category. These relatively benign materials are really the face of modern pesticides - not what most people imagine.

The category II, III and IV products include a mix of synthetic products and natural products which could qualify for organic.  The total area of organic grapes is small, but in this and other crops there is a substantial overlap between the pesticides used in conventional and organic.

Another Way To Look At The Data

The EPA categories are rather broad, so another way to look at this is to "weight" the amounts based on their relative oral toxicity.  In the graph to the right I have taken the foliar, non-sulfur numbers and multiplied them all by the value 500/Oral ALD50.  500mg/kg is the dividing line between "slightly" and "moderately" toxic in the EPA categories.  Thus a product with a toxicity of 4000 mg/kg is counted as 1/8th of its weight in pounds.  A product with a toxicity of 40mg/kg is counted as 12.5 times its weight in pounds.

From this approach we see that even though almost three times as many pounds of foliar applied, non-sulfur pesticides are being used on grapes in recent years, there has really been no increase in the overall "toxic load" involved.

In the 22 years covered by this data set, there have been some dramatic changes in the nature of pesticides used. The crop and product in this case may be quite special (and delicious), but the trend is not unique to wine grapes.  We would see a similar change in most crops.  This sort of change didn't happen by accident.  It represents a great deal of work by a diverse collection of players in the public and private sphere. I'll go into that in detail in the next post in this series.

You are welcome to comment here and/or to email me at savage.sd@gmail.com

Napa vineyard image from Almonroth via Wikimedia Commons
All graphs mine based on CalPIP data correlated with acreage data from California County Ag Commissioners Reports

Primer on the Measurement of Acute Toxicity

There are many dimensions of toxicity, but the most basic is how toxic something is when consumed.  This is what would be of concern for pesticide residues.  This is called Acute Oral Toxicity and it is determined by feeding different amounts of a chemical to a population of rats or mice.  The dose relative to the animal's body weight that kills 50% of the subjects getting that dose is called the LD50.  It is expressed as milligrams of chemical per kilogram of body weight.  For these numbers the larger the value, the less toxic the compound.    For reference, table salt has an oral ALD50 of 3,000 mg/kg.  For a 120 pound (54 kg) person that would mean a toxic dose of 163 grams which is about 1/4 of a normal, 1 pound canister of salt.  For that same person, the toxic dose of caffeine (oral ALD50 191 mg/kg) would be 10.4 grams - what one would get from 32 servings of nice coffee at Starbucks.  In both cases, the salt or coffee would need to be consumed very quickly to achieve that dose.  Some of the most toxic insecticides ever used had oral ALD50s in the range of 5-10 mg/kg.  Most pesticides today have oral ALD50s of more than 5,000 mg/kg (Category IV) and are less toxic than table salt, vinegar, citric acid, vanillin and many other familiar food ingredients.

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