Pesticide Residues on Organic: What Do We Know?

Are there really less pesticide residues on organic crops?  The answer might not be as simple as you think.

A few weeks ago it was announced that for the first time in the history of USDA-Organic, there will be mandatory pesticide residue testing starting in 2013.  This was always a theoretical possibility, but a government audit of certifiers showed that it essentially never happened.  Now it will, at least to some extent (something like 5% of operations)

I wrote to the contact person at USDA to ask this question:

"will this new testing program look for any residues of the pesticides that are allowed on organic crop and thus applied frequently?"

Why Ask This Question?

Most consumers believe (erroneously) that organic crops are not sprayed with any pesticides at all.  That is not true, and the criterion for what can be sprayed on organic has nothing to do with relative risk - it is simply based on whether the pesticide is deemed "natural."  Knowing what is actually sprayed on organic crops, I was particularly interested in the copper-based fungicides because they are rather toxic by modern standards, and about Bt, protein insecticides because it would be helpful to calm people freaked out about Bt-biotech crops to be able to compare the exposure to this ultra-safe material when they probably consume farm more that is sprayed on crops vs when it is expressed by the crop.

Unfortunately, I learned that this new testing program is only there to encourage compliance with the organic rules, not to document anything about relative residue levels.  There will be no testing for organically approved pesticides.  In fact there won't be any public data-base generated and the sampling will be at the discretion of certifiers - not random.

This leaves us with the same situation we have had for a long time.  Organic advocates and marketers make regular claims about the advantage of organic with regard to pesticide residues, and yet there is no actual data to support that claim - at least not for the US.

But Didn't That Stanford Study Compare Residues?

Remember the recent "Stanford Meta-Study" comparing organic and conventional that stirred so much controversy?  They found lots of studies about nutrient content, but in their extensive search of the scientific literature they were only able to find 9 studies that compared pesticide residues in organic and conventional.  Only one of those was even from the US and it was from the mid 1990s.  It was based on a testing program at USDA called the PDP (Pesticide Detection Program).  While that group does an excellent job of monitoring pesticide residues on conventional crops, it has never looked for the pesticides most likely to be found as residues on organic - things like copper salts.  So even that one study that the Stanford group cited for the US was not a meaningful piece of data for residue comparison.  So much for the scientific literature as a source on this question.

Why Doesn't the PDP Test For Copper, Bt, Biologicals Etc?

I contacted the USDA scientists who run the PDP to ask why they don't test for things like Copper fungicides, Bts or other biologicals.  The answer was quite practical.  They use something called multi-residues methods (MRMs) with which it is possible to simultaneously test for 2-300 different synthetic pesticides in a single analysis run.  However, because of solubility issues and detection technology differences, many organic-approved pesticides cannot be extracted or measured by the same protocol.  To do the testing for these individual categories of pesticides would be far too expensive for the budget of that agency.  The random sampling method of PDP is also not well suited to getting enough organic samples for comparison.

Can We Compare Residues?  No.

So, here is where we stand on the question of pesticide residues on food.  The conventional supply is rigorously tested for the main products they intentionally apply as well as for any off-label or environmentally persistent products left over from the bad old days.  We get a data set every year which essentially says that there isn't anything to keep consumers from confidently buying that food.  The organic food supply is going to be tested to some degree for the first time, but we won't see any real summary of that data nor will we be able to compare it to conventional.  We also know that there won't be any data generated about the pesticide residues most likely to be present on organic.

Do We Know Anything About Pesticide Residues On Organic Crops?

There was a relatively small, but high quality pilot study conducted by the USDA as background for their new testing regime.  The authors were careful to point out the multiple reasons that their data is not really comparable to PDP (limited number of crops, smaller sample size not collected in the same fashion, fewer chemical tests conducted...).  What they did find was that there were definitely some synthetic pesticide residues detected on organic crops - mostly consistent with spray drift, accidental contact in packing houses, persistent environmental pollutants....  The levels they found were not problematic from a safety point of view, but that is just as true for the PDP testing of conventional crops.  This pilot program was like the PDP in that it used MRMs and so it didn't test for the majority of organic pesticides.   So, bottom line, we still have no real data about the most likely pesticide residues that occur on organic crops and we are unlikely to get any.

What Would Happen If We Could Get Information About Organic Residue Status?

If organic were subjected to the same level of random and comprehensive testing that is used for conventional, and if all its pesticides were included, it would almost certainly come out "dirty" by the absurd and irresponsible methodology employed by the Environmental Working Group to create its annual "dirty dozen list".  They just count detections without regard to the nature of the chemical in question or its concentration or its EPA tolerance.  If there ever were a comparable pesticide residue database for organic it would force a far more scientific discussion of which residues matter and which do not.  My guess is that both conventional and organic would come out as just fine for consumers to eat, but the "organic advantage" would disappear when both types of food had to be compared using scientifically sound assessments.

Bottom line.  Just eat your fruits and vegetables and whole grains.... enjoy them!

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

Organic produce image from Pculter's Photostream

What Would A Real "Right To Know" About Food Look Like? Not CA Prop 37

If California Proposition 37 is really about a "Consumer Right To Know," then why is it talking about a few words in a tiny font on the back of a package?  Why are we only talking about one question (GMO or not) when there are so many more issues people could care about? Why are we talking about something that only involves selected types of food in only one state?  None of this sounds like a sincere or even rational way to let people "know" something about their food.  It also sounds so "last century!"

Why Accept Minimal Information?

The "information age" is unfortunately also the "disinformation age."  There are a host of sources out there saying all sorts of negative things about genetically engineered crops - things which are clearly at odds with the scientific consensus around the world.  In many cases the entities behind these critiques have much to gain in product sales or fundraising is consumers can be frightened about GMO foods.  That is certainly the case for many sponsors of Proposition 37.  A few words on a package is a very poor way for a consumer to come to "know" anything except what these entities want them to "know," which is "be afraid and buy what I'm selling instead."

In the internet, smart-phone age there would be so much better ways to allow people to actually get some knowledge about their food.  Most products have a bar code, a PLU sticker, or some other way to link to data.  Consumers could have an "app" or their mobile device that uses that code to take them to a wealth of product-specific information that could be accompanied with the background or perspective to move from some isolated factoid to actual "knowledge."  Alternatively, consumers could access the information on a computer or even on a terminal provided by the store.  The key is setting up an authoritative, current, user-friendly and independently verified place to go find reliable, unbiased information.

Who Should Do This?

I think this would be best run by a non-governmental, not for profit entity with no economic ties to food companies, biotech companies, anti-technology organizations, organic marketers.  It should have a transparent list of highly qualified technical advisors from academia.  It should have a group of communication experts who really understand how to present technical topics for a broad audience.  It should have advisors from the farming community and the commodity system who can tell those communicators how things really work in the largely unfamiliar realm of agriculture. It should have some seriously tech savvy people to set up the site(s).  Thought needs to be put into how to fund this because it is fair that the food and biotech industry help foot the bill, but in a way that does not give room for even suspicion of conflict of interest.  It may be that charitable sources can also be tapped.  If all the money spent on the Prop. 37 battle could have been used for this it could have been funded for years.

What Information Should Be Available?

The first thing that could be done is to make a very easy way for people to know whether any given crop does or does not even have commercial GMO varieties that could ever end up in the store.  Anti-GMO sites usually use graphics of crops which never have been and in most cases will probably never be GMO.  For instance, very few crops in the fresh produce arena are GMO.   This list could easily be maintained by for the "right to know' site with help from the USDA.

For crops that have been improved using transgenic methods, there should be an easy way to see what the traits are, how they work, why they are useful to farmers, what advantages they may have for consumers.  For each one there should be a balanced presentation of the issues that have been raised from a health or environment perspective and what data has been generated and reviewed to evaluate them.  This information is not something new, but it would be an advance to get it all into one place with independent credentials and easy access.  There should also be a clear description of the food ingredients that are most likely to include supplies from GMO plantings and how to recognize those on a label.

Finally, there should be a way to get information on a product-by-product basis using bar codes or other identifiers.  The information presented should probably be voluntary on the part of the company responsible for making the product, but it would also go through an independent review.

Examples Of What People Could Know

Lets consider some examples of how this system could help consumers actually know things about their food.  Lets say you want to buy some corn tortilla chips.  Corn is a crop which is mostly GMO since the 1990s.  Most of this crop is used for animal feed or for ethanol production.  A relatively small part of it goes into food ingredients like corn starch, corn meal, high fructose corn syrup an other things.  A very small part of the total corn crop is used for making corn tortillas and tortilla chips.

One manufacturer of tortilla chips might say that they contract for special corn hybrids that are particularly well suited to chip making, and they decided to use non-GMO versions of those because they thought there was a customer base that would be willing to pay a bit more for that.  Another manufacturer might say that they intentionally use corn from the normal, mostly GMO supply because that corn is less likely to have mycotoxins like Fumonisin which is related to the sort of insect damage which Bt corn prevents.  The informed consumer could then decide which chips they want to buy.

Or consider soybean oil.  A food manufacturer or restaurant may say that they have specifically chosen to use the high oleic acid soybean products that have been developed using biotechnology.  This is a more functional oil for many foods and also a healthier oil because it is a solution for avoiding trans-fats.   The manufacturer could also say that since these and other GMO soybeans are herbicide tolerant, it makes it easier for farmers to use "no-till" farming techniques which are better for the environment in many ways.  Another manufacturer may explain that they use US, GMO soybean products because they do not feel confident in the non-GMO soybean-based ingredients on the market which may come from places like China.

The independent entity would summarize the safety assessments of each trait by expert panels around the world and that information would be linked from the product-specific site so that a curious consumer could see what is known on that front.

A system like this would actually allow consumers the opportunity to know about their food in a meaningful way.  Proposition 37 would not accomplish that goal.

You are welcome to comment here and/or email me at savage.sd@gmail.com
No on 37 Logo from www.noprop37.com