Anything Scary About California's Produce Options This Halloween?

California Food Safety Check

Each year the California Department of Pesticide Regulation (CalDPR) collects produce samples from multiple steps between the farmers and consumers. They recently released their results for 2018.  They tested a total of 3,666 samples of 140 different crops grown in California, other US states and items that were imported from 25 different countries.  For each sample they analyzed for 400 different pesticides or their known breakdown products.  This is also part of an enforcement program so it is great that they are still so transparent with their findings.

As with previous surveys, the results document the fact that the growers who produce our food are following the EPA label requirements that are designed to insure that by the time it gets to consumers is quite safe.  That safety standard is based on national standards set by the EPA.  For 78% of the crops there we either no detectable residues or residues below the legal limits. Few of the remaining examples were at all problematic

Particularly for the US grown samples, excessive concentrations were very rare.  There were some residues of chemicals found which are not technically supposed to be used on that crop, and as in the past most of these “no established tolerance” cases were on the imported items.  

The residue issues varied quite a bit by source. Those from different parts of the US were similar, but those from China, Mexico and Central America had more cases of "no tolerance." Perhaps the best profile was for crops imported from South America.

301 of the items were being sold as “Organic.”  The rule for organic set by the USDA is that no detected residues should exceed 5% of the EPA tolerance .  In 2018 only 55.4% of detections from organic sample met that standard so they should not have been able to be sold as "USDA Organic Certified."  Imported organic residues over 5% of the tolerance made up 66.7%  of detections which is very similar to that same measure for domestic conventional produce.  55.4% of the detections on imported conventional crops would not have disqualified them if someone was trying to sell them as organic.  Below is the list of specific pesticide residues that were found on organic samples.   

AMETOCTRADIN 1, BIFENAZATE 1, BIFENTHRIN 1, CAPTAN 1, CHLORPROPHAM 2, CYAZOFAMID 1, CYPERMETHRIN 1, CYPRODINIL 1, CYROMAZINE 1, DDE 5, DIELDRIN 1, FENAMIDONE 1, FLONICAMID 2, FLUBENDIAMIDE 1, FLUDIOXONIL 4, FLUOPICOLIDE 1, FLUOPYRAM 3, FLUPYRADIFURONE 1, IMIDACLOPRID 2, MANDIPROPAMID 1, PENDIMETHALIN 1, PENTHIOPYRAD 1, PERMETHRIN 2, PROPAMOCARB 1, PYRACLOSTROBIN 1, PYRIMETHANIL 1, ROTENONE 2, SPINOSAD 16

Those who think they are buying something safer by spending more for organic might want to rethink that logic. Only the 16 spinosad detections represent something allowed for use on organic, and organic still has the legacy of residual DDT metabolites like DDE.

While CalDPR made it very clear that this report was good news, they called out seven commodities for which they though the residues could be a legitimate health concern. These are Dragon Fruit (Vietnam), Chayote (Mexico), Lychee (China), Cactus Pear (Mexico), Star Apple (Vietnam)m and Tomatillo (Mexico).  They also added Star Apple from Vietnam  and Guaje from Mexico because of products found there for which there is no set tolerance.

Once again this is evidence that our food supply is safe and also incredibly diverse. This testing program is different from the USDA’s Pesticide Data Program (PDP) in that it includes a number of more exotic items. However it also includes many more mainstream fruits and vegetables and among those there were no above-tolerance detections. But in both cases the take-away is that we should enjoy our fruit and vegetable options and consume them as part of a healthy lifestyle.

                                                                                                                                        

Do You Really Need to Worry About Pesticides on Your Kale?

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Bundle of Kale (Wikimedia commons)

Last week the Environmental Working Group (EWG) published its annual “Dirty Dozen List” and highlighted Kale near the top of it’s list of foods with “pesticide residue contamination.” They want you to buy your Kale as Organic.  EWG claims to base that recommendation on data from the USDA’s Pesticide Data Program (PDP), but a closer look at the actual data suggests a far different conclusion – that the Kale in our food supply is quite safe and that there is not the big difference between organic and conventional that they imply.

Since EWG gets much of its funding from large organic marketers, it is not surprising that their recommendation is to buy organic, but the 2017 PDP testing included 67 samples that were labeled as USDA organic (13% of the total for Kale).  Many of those organic samples had detectable residues representing 31 different chemicals, only one of which is approved for use on organic crops (Spinosad).

Now the levels at which chemicals were detected on the organic were very low and of no health concern based on the very conservative “tolerances” set by the EPA through its extensive risk assessment process.  However, the same can be said for the 455 conventional Kale samples tested the same year of.  The residues we are talking about here are hundreds to thousands of times below the relevant tolerance (see graph below).

In theory there wouldn’t be any synthetic residues on organic, but the USDA’s certification rule allows for “inadvertent” presence of synthetics at 5% or less of the EPA tolerance. (There is a separate USDA-Organic compliance testing program that looks for residues, and in that case the 5% rule applies).  98.9% of the 2017 PDP detections for organic Kale samples would meet that standard, but so do 98.1% of the residues on conventional samples.  Not so different, eh? In the graph above, only the red part of each bar would be a technical violation of the organic rules and none of the Kale detections for either conventional or organic exceeded the tolerance. Note that neither category is actually “dirty” based on a rational, scientific assessment.

Now, there were about three times as many residues/sample found on the conventional Kale, but the USDA does not even test for a great many of the pesticides that are approved for and regularly used on organic.  This would include “natural products” such as mineral-based materials (e.g. sulfur or copper compounds), petroleum oils, plant extracts, and biologicals).  Those sorts of products make up a substantial part of what gets applied to Kale. Thus, pesticides which are not part of the PDP testing make up 65% of the total pounds of crop protection agents applied to kale and 44% of the treatment acres (see graph below from the most recent available year of California use data).  Approval for organic is entirely based on what is considered to be “natural” and the USDA is quite clear that the classification is not about relative safety.

The acreage of Organic Kale has been increasing over the last 15 years and with it the use of the organic-allowed pesticides.  (See the example of sulfur use on Kale as linked to organic acreage in the graph below).

If the USDA tested for residues the natural product pesticides, the number of “detections” for organic samples would certainly increase. But as with the synthetics, the results would most likely indicate that this is a perfectly safe vegetable to consume whether or not it is organic.  Bottom line, the wisest thing for consumers to do is to ignore the fear-mongering of the EWG and simply enjoy a healthy diet including lots of this and other fruits and vegetables.

Why Organic Can't Fulfill Our Food Supply Ideals

Almost any farmer or consumer could agree on the following ideals for our agricultural system:

"Farming in ways that are best for us, best for the environment, and best for providing an adequate food supply."

I believe that these are the goals and ideals of organic customers and organic farmers, and I share them. If organic could deliver on these “triple best” goals, I would be among its strongest supporters, but I don't believe that it can.  The organic rules are based on the assumption that “natural” is always best.  That assumption originated in a pre-scientific era, and it does not hold up to what we have learned over the last century.  The "natural" definition is great for marketing purposes, but often not the optimal criterion to guide farming practices. 

The Original Contribution of the Organic Movement

The important contribution of organic early in the last century was its focus on improving soil health/quality.  The pioneers of the organic movement worked out certain farming methods using “natural fertilizers” to mitigate the nutrient-depleting and soil-degrading effects of the plow-intensive farming of the late 19^th and early 20^th century.  The organic focus on natural also meant that it eschewed some of the early pesticides, which were later found to be problematic for health and the environment.  For a period of time, organic may have been, in fact, the best farming option for us and for the environment.

A pretty picture, but for soil erosion and soil health this kind of farming was highly undesirable

Since then we have learned more and more about environmental systems, genetics, microbiology and human health.  Based on that, increasingly rigorous regulatory processes were put in place and farming practices have changed dramatically.  Sometimes organic growers were in the lead in making those changes.  But increasingly, the “natural” constraints of organic are making it difficult or even impossible for organic farmers to implement what we now know to be best for us, best for the environment, or best for the food supply.  I'd like to describe six specific examples of those limitations.

1. Nitrogen Fertilization

One of the greatest challenges of farming is providing a growing crop with the necessary mineral nutrients when it needs them. When nutrients are free in the soil and not being actively absorbed by the growing crop, they have the potential to move into ground water, or to wash off into surface water.  If they do, they can become health issues and/or foster algal blooms that cause “dead zones” in bodies of water.  Excess nitrogen in soils can lead to the generation of the potent greenhouse gas, nitrous oxide. There are specific conditions under which natural fertilizers like manures or compost can reduce these problems, but there are also conditions under which the uncontrolled, nutrient release pattern from natural fertilizers can be quite problematic. Depending on how and when they are delivered, “synthetic” fertilizers can be deployed in ways that do a better job of providing the crop’s need without as much risk of these forms of pollution. For example, drip irrigation systems are very efficient ways to deliver fertilizers but cannot be used for most forms of organic fertilizers. Triple-best farming requires the ability to use both natural and synthetic fertilizers in the right settings and with the right delivery methods. There is even the possibility of making synthetic nitrogen using renewable energy.  

2. Low Risk Pesticide Use

What makes a pesticide safe for us or for the environment is not related to whether it is “natural."  Some of the most toxic chemicals known are produced in nature. The reason that the American consumer can have confidence in the safety of crop pesticide use is that the EPA demands a great deal of data for its multi-dimensional risk assessment for any chemical, natural or not, that is going to be used for pest control.  These tests involve multiple dimensions of human toxicity as well as assessments of environmental fate and environmental impact. Some, but not all “natural products” meet those standards.  Some, but not all, synthetic products meet those standards.  The details of how synthetic or natural pesticides can be used are then dictated in “label requirements” specific to the properties of that chemical (e.g. how long before the crop is harvested, what worker protection standards are needed, what considerations are needed relative to sensitive environmental settings…).  It is this regulatory process, not naturalness, which ensures environmental safety and residue levels that are safe even by very conservative standards.  In many cases the "synthetic" options are the very best choice among the approved options. 
(Note: the graph of California use data shown earlier has been removed.  Sulfur classified in that figure as Category II is actually Category IV for oral acute toxicity, Category III for dermal toxicity)

3. Fully Integrated Pest Control

Baby Spinach Growing In Coastal California

Organic farmers have been early adopters of many pest control options other than classical, chemical pesticides (genetic resistance, biological controls, crop rotations, natural pest enemies, and pheromone-confusion…), but at least since the 1970s, this has also been a growing component in “conventional agriculture” called Integrated Pest Management(IPM).  In many crop systems, modern synthetic pesticides are one important component in these mixed approaches.  For example, there is a problem in the current, California spinach crop, which has around 50% organic production.  There is a disease of that crop called downy mildew and it is transmitted from season to season via survival in the seed.  Through conventional breeding, it has been possible to develop spinach that is resistant to that fungus.  The conventional growers also use a relatively benign synthetic fungicide as a seed treatment against the disease - thus they are using an integrated program of genetics and a fungicide.  For the organic production, the seed treatment is not allowed.  Without the multiple control strategy, the fungus has rapidly mutated to get around the genetic resistance, and six good sources of resistance have been lost within a few years.  Each time, the newly virulent strains have emerged first in the organic fields. This gap in the IPM program is now putting the entire California spinach industry at risk.  There are similarly precarious situations in other crops.

4. Biorationals

It takes a lot of money to do the testing needed to commercially develop and insure the safety of any new agricultural pesticide - more than $200MM.  That level of spending is appropriate to meet our modern safety standards, but it means that the commercial development of any new synthetic pesticide can only be justified for a very large market within the agricultural realm.  For problems that only affect a small part of the food supply, it is not possible to justify the investment in a new option.  Fortunately, the EPA has a special, lower cost registration process for low toxicity chemicals that already occur within the food supply. 

The sprouts of potatoes are actually rather toxic, so don't eat them

A good example of this is a new product for preventing sprouting in stored potatoes.  The compound 3-decen-2-one already occurs in at low levels in potatoes as well as in mushrooms, tuna fish, yogurt and soy.  An identical, synthetic version of the chemical can now be used with stored potatoes and it is a better, safer option than the old sprout inhibitor, CIPC.  Because of a purist interpretation of the organic rules, the new sprout inhibitor cannot be used for organic potatoes.  Instead they are treated repeatedly with clove oil – a more costly and less effective option with no other “triple best” advantages.

5. Soil Building

Starting in 1960, farmers have been working out farming systems that do not require physical tillage of the soil.  When these are combined with the use of cover crops and GPS guided equipment use, it is possible to raise the important row crops (wheat, barley, canola, soybeans, corn, cotton…) in no-till or minimum-tillage systems that improve soil health and quality.  It is also an important “best” system to prevent soil erosion, reduce water pollution risk, and sequester carbon to mitigate climate risk. 

No-till Soybeans Following Corn

This system is much more like the way soils are built in natural prairie habitats and is not dependent on outside inputs of organic matter as is the case in the typical organic systems.  In order for these new options to be pursued efficiently on a large scale, herbicides are necessary as are controls for certain pests which are favored in a non-tillage system.  Organic growers don’t have many of the practical tools to manage these issues, and so they are ironically unable to fully or cost-effectively pursue these best, reduced tillage protocols.

6. Genetic Improvements

Genetic modification of crop plants has always been an important means of making farming better able to meet our food supply goals.  In recent history it has become possible to make more precise genetic modifications using the tools of genetic engineering – tools which were in fact drawn from nature. For example,  restriction endonuclease enzymes occur naturally and cut DNA at specific target sites, and the Ti plasmid of Agrobacterium which inserts DNA into chromosomes of plants.  In the last few years, even more precise and efficient tools for genetic modification have been discovered within a group of ancient microbes we call the Archaea (e.g. the CRISPR-Cas9system). 

Diagram of the CRISPR system via Wikipedia

As deployed within the unprecedented and rigorous regulatory framework for "GMO Crops", these tools have become an important means through which triple-best crop improvements can be made.  In her book “Tomorrow’s Table,” UC Davis molecular biologist Pamela Ronald has made an articulate argument for why these tools should be embraced for organic farming. But such suggestions are not even considered by the fierce defenders of the organic rules.  Even when genetic engineering is used to transfer something like a gene from wild potatoes into commercially relevant potatoes, the resulting triple-best crop will not be available to organic farmers (as in the case of the new, Innate 2 potato from Simplot)

European experiment showing healthy potatoes on the left that have the wild potato gene vs susceptible potatoes on the right without that gene

 A Missed Opportunity to Embrace Best Practices by Organic

There was a window of opportunity in 1990 when the organic rules could have been updated to use science-based criteria rather than the restrictive obligation of natural.  In that year, the US Congress tasked the USDA with formulating a national organic standard, and that research-oriented agency was inclined to bring modern knowledge into their rule-making process.  Such an approach was vigorously opposed by key elements of the existing organic advocacy community.  When the national standard emerged in final form in 2000,  at had only enshrined the "natural requirement" which continues to limit the ability of farmers to pursue many triple-best strategies such as those I’ve described above. 

Unfortunately, some of those who market organic products, and some who advocate for organic, continue to make unsupportable claims that organic is best for us and for the environment.  Many consumers accept these claims and believe that they are doing the right thing by paying the premium prices for organic items.  If we really had a food supply that was only safe and responsible for those able and willing to pay higher prices, that would represent a huge failing of public policy.  Fortunately, that is not the case.  Consumers and farmers with high ideals for the food supply can support farming in the ever-innovative mainstream system as it continues to find ways to farm that are best for us, best for the environment.

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

Do You Really Need to Buy Organic Foods To Avoid Pesticide Residues?

Last week, a meta-analysis from a highly credible, academic source (Stanford University, its medical school and nearby institutions), raised serious questions about the often-touted, nutritional advantage of organic food.  They digested the contents of 237 peer reviewed articles comparing organic and conventional foods and diets.  They concluded that "the published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods."  This drew a great deal of attention and organic advocate defense.  Because even though Stanford is affectionately known by alums such as me as "the farm," it is certainly no ag-school promoting the status quo.  Instead, it enjoys a very strong reputation for research excellence.   It isn't easy to dismiss these findings.

Many commentators, confronted with the highly credible de-mythification of the nutritional advantage of organic, jumped to the paper's slight evidence supporting a 30% reduction in exposure to pesticide residues as a way to justify paying extra for organic. Does the science really support that claim?  No.

What I found disappointing about the Stanford study was the weakness of its analysis of differences in pesticide residues.  First of all, of the 9 papers it analyzed on this topic, only one was based on US crops.  Seven were about European food and one was from Australia.  The single US study used data from the 1990s.  Since that time there have been significant declines in the usage of older, more toxic pesticides.

The Stanford-associated authors drew the cautious conclusion that "consumption of organic foods may reduce exposures to pesticide residues...", but they didn't do anything to put that statement in perspective.  In fact, their analysis was only a comparison of the number of pesticide detections with no consideration of which pesticides were detected at at what levels.  Without that information, one can easily be counting,  as equivalent, chemical residues that could differ by a factor of a hundred thousand or million in terms of relative risk.   The Stanford group may have been limited by doing meta-analysis instead of original research, but in any case this sort of "detection counting" is the same egregiously misleading "analysis" that is committed each year by the Environmental Working Group in compiling their "Dirty Dozen List."

How Would You Best Answer Questions About Pesticide Residue Safety

The truth is that at least for the US, there is a perfectly good way to answer the question, "Should we be concerned at all about pesticide residues on our conventional food?"  There is a publically available, fully transparent, downloadable data-set that provides exactly the information needed to get those answers. Each year, a group in the US Department of Agriculture (USDA-AMS) conducts a huge effort called "The Pesticide Detection Program." (PDP).  They collect thousands of samples of food commodities from commercial channels throughout the year, and then take them back to the lab and analyze each for hundreds of different pesticide residues.   It is effectively a "report card" on the entire food production system about how well it protects consumers from undesirable pesticide exposure.

I've been working for a while to do a rigorous analysis of the latest available PDP data from 2010.  It has been a daunting task, because it is a nearly 2 million row, 85MB document. It contains a great deal of useful information in a form not easily accessed or understood by the public.  However; once this is data iscrunched; it is easy to see why the USDA, EPA, FDA conclude that consumers have no need to worry about the safety of their food supply from a pesticide residue point of view.

The graph above shows that the vast majority of the residues that the USDA scientists detect are at less than one part per million (1 milligram/kilogram).  There really are not very many chemicals, synthetic or natural, that are of concern at these levels, but fortunately the USDA data does identify what the chemicals were and one can find out about them by searching for an MSDS (Material Safety Data Sheet).

When most people hear the word, "pesticide" they imagine something quite dangerous.  What they don't know is that over the last several decades, the old chemicals have been steadily replaced by much less hazardous ones that have emerged from a multi-billion dollar discover effort.  That is why 36.6% of the residues detected in 2010 were for chemicals that are less toxic to mammals than things like salt, or vinegar or the citric acid in your lemons (see graph above).   73 percent of the detections  were for pesticides that are less toxic than the vanilla that is in your ice cream.  90.5 percent of the pesticides detected were less toxic gram per gram than the ibuprofen that is in the Advil tablets that tens of millions of people take on a regular basis.  95.4% of the detected residues were from chemicals that are less toxic than the caffeine that is in your coffee each morning.  "Pesticide" does not equal "danger."

Even so, the best way to answer the question, "should I worry about pesticide residues?" is to compare what was detected to something called the "EPA tolerance."  Companies that want to register new pesticides or to continue to use older ones spend well over $100 million dollars and several years of research to characterize the hazards (or lack thereof) that are associated with each chemical.  These are used to inform a sophisticated, EPA-driven  "Risk Assessment" process that determines if the chemical can be used and with which restrictions (e.g. how long the use must stop before the crop is harvested.)  The "tolerance" that comes out of this process is designed to set a maximum level of that pesticide residue that should be detected in practice. This value includes a generous safety margin (on the order of 100x).  Anything that is detected which is below the tolerance is not of any concern.  The tolerances are set specifically by chemical with differences for each crop to reflect  differences in the amount people would eat and which crops tend to be consumed the most by children.  

What Does The Residue Testing Say?

The reason that the USDA can look at their data and make strong statements about safety is that the residues they find are virtually all below the tolerances, mostly far below (see graph above.)  Only 7.8% of the residues detected in 2010 were even within the range of 0.1 to 1 times the tolerance.  More than half were less than 1% of the tolerance (see graph above).

The Stanford study cited a 30% reduction pesticide residue detections which is essentially meaningless in the context of the miniscule risk associated. Unfortunately, many consumers have been convinced that there is a risk where there isn't one.  They have gotten this from misleading promotion of organic as "pesticide-free" when it isn't, and by the scaremongering of groups like the EWG. The net effect of consumer concern about pesticide residues, driven by distorted messaging, may be a reduction in fresh fruit and vegetables consumption (see graph below).   After some modest increases in fruit and vegetable per capita consumption in the 80s and 90s, those trends have ceased or even been reversed.  How much of that is related to disinformation about the risks associated with pesticide residues?  A study by the Hartman group found that some consumers said they reduced their produce purchases specifically because of the "dirty dozen list."  The question needs more research.

This new study, even if it is from Stanford, does not provide consumers meaningful guidance on the question of whether they should spend more to avoid pesticide residues.  The more relevant USDA data says that they don't need to hesitate to buy and consume "conventional" foods.

You are welcome to comment here or to email me at savage.sd@gmail.com.  Graphs are based on USDA-AMS pesticide data and USDA-ERS produce trend data.

A Curious Silence: The Environmental Working Group and Mycotoxins

The Environmental Working Group (EWG) tells us:

"The mission of the Environmental Working Group is to use the power of public information to protect public health and the environment."  

If you look at their website, a great deal of what they do involves warning people about various "toxic risks."  They publish an annual "dirty dozen" list ranking crops by pesticide residues.  They have a major effort to identify purported risks from chemicals in cosmetics and sunscreens.  They look at toxic things in drinking water and in pet food.  They have an extensive "Chemical Index" with toxicity ratings.  But there are some very important toxins about which EWG is completely silent.

The Missing Toxins

The extremely important class of toxic chemicals that is completely absent from the EWG website is Mycotoxins.  You can go to the search engine on the site and enter words like: mycotoxin, aflatoxin, fumonisin, ochratoxin, vomitoxin... and find absolutely nothing.  What makes this silence so strange is that mycotoxins are known to be some of the most dangerous substances to which people can be exposed, particularly in food.  If one of EWG's primary purposes is to "protect public health" it seems odd that they would not say one thing on their web site about this extremely well-documented risk.

Beth Hoffman, an information technology writer, raised an interesting issue today in an article in Forbes.  She was discussing the huge disparity between what government and academic scientists say about pesticide safety and what the Environmental Working Group says with its "Dirty Dozen" list.  She says, "But at its core, the argument for and against lists like the Dirty Dozen is a question of trust."

The EWG clearly distrusts the scientific/regulatory consensus.  But should consumers trust the EWG?

Should we trust an organization that either ignores or fails to recognize a real and present risk when they are telling us that there is significant risk where science says there is not?  EWG says it "provides practical information you can use to protect your family and community."  How can we trust that statement if EWG provides zero information about chemicals which are not in the "you just never know" category, but in the "clearly documented as toxic and carcinogenic" category?

What Are Mycotoxins?

Mycotoxins are potent, natural chemicals which are produced by certain fungi.  These fungi can, under various circumstances, grow on food and feed crops either while they are growing in the field, or later during the storage and/or drying of certain commodities.  The most important example is a toxin called aflatoxin which is produced by some strains of the fungi Aspergillus flavus and Aspergillus parasiticus.  These organisms can grow on things like peanuts, tree nuts, and corn.  It can also grow on hot chili's or figs while they are drying if that is done improperly.  It can occur in imported spices like nutmeg.  It has been found in imported chocolate.  It is thousands of times more toxic than most pesticides, and it is one of the most potent carcinogens known.  It is estimated that aflatoxin is the a major  cause of cancer deaths world wide.  Unfortunately, this mainly occurs in the third world, and even places like China are just now beginning  to address the issue.

Why Haven't Most People Heard of Aflatoxin or Other Mycotoxins

In the developed world, extraordinary efforts are made to keep food mycotoxin levels in general, and aflatoxin levels in particular, low enough to make our food safe.  The system works well enough that it does not come to the public attention very often.  This success is based on the same sort of science-based regulation and testing that are designed to insure that pesticide usage is safe.  The system of mycotoxin exclusion generally does a great job, but occasionally something slips through - mostly incidents involving pet foods or imported products from regions of the world that don't have adequate safety practices in place.

Just as an example, nut crops like peanuts and almonds can potentially become contaminated with aflatoxin, usually because of insect damage.  In our food system, the individual, shelled nuts that go into something like peanut butter or roasted almonds are put one-by-one through a light-based screening process to reject any individual nut with even the possibility of contamination.  Peanuts and other nuts sold in-the-shell cannot be screened to that degree.  EWG could instruct consumers to avoid in-the-shell nuts to protect their family. It has also been shown that eating green plants like spinach gives us chlorophyll which can bind aflatoxin in the gut so that it never gets into our blood stream.  EWG could recommend that one eats a salad with peanut butter sandwiches just to be safe.  EWG could talk about which imported foods might be most likely to have aflatoxin.  These examples would be practical guidance about real risks.  On such issues, the EWG has long been silent.   Contrast this with the proactive efforts by the Bill and Melinda Gates Foundation to address mycotoxin issues in the third world.  Yet this major oversight is not the only reason to distrust EWG.

A Serious Issues With the Way That EWG Does Its Analysis

An analogy might be helpful here.  Domesticated dogs come in a huge range of sizes from tiny Chihuahuas to huge Mastiffs.   They also come in a huge variety of personalities, from breeds which you could easily trust with a baby to those which have been bred for aggressiveness and which have been known to maim and kill people.  If anti-dog activists were to propose that any dog should be avoided and that people should move to towns that exclude all dogs, most people would dismiss the idea as ridiculous.  This is; however, directly analogous to what EWG does with pesticide residue data and their "solution" of buying organic.  The amounts of pesticides that the USDA finds on foods in its residue testing program can vary by 1000-fold or more - actually much more than the range of dog sizes.  The intrinsic properties of the different chemicals that are detected also differ even more than the differences between aggressiveness in breeds of dogs.  Yet what EWG does when it makes its dirty dozen list is to treat every residue detection the same.  This is just like our fictitious anti-dog activist who says that all dogs represent a equivalent risk, or that you just never know about any dog.  Why should anyone trust this method to analyze risk?

Beth, the Forbes writer, gives indications that she tends to distrust the scientific/regulatory consensus.  I wonder if she has thought about whether she should trust the EWG? Do you trust an organization uses a seriously over-simplified analysis of one category of chemicals while ignoring toxins of far greater concern?  Or might it make more sense to trust science backed up by government and academic scrutiny?

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

Aflatoxin contaminated groundnut image from IITA Image Library

How The USDA Unwittingly Aids EWG's Pesticide Disinformation Campaign

Each year, the Agricultural Marketing Service of the USDA (USDA-AMS) conducts an extensive sampling and analysis of items from the actual US food supply to determine what, if any, pesticide residues are present at the consumer level.  This information is published each year, and the actual raw data is also available for download.  The data for 2010 was just recently released.

What Does The Data Actually Tell Us?

For 2010, as for preceding years, the data demonstrates is that pesticide residues are only present at very low levels, usually dramatically below the conservative "tolerances" set during the risk analysis by the EPA.  This is quite remarkable considering that pesticide use on crops depends on many thousands of independent decisions by many thousands of individual farmers both in the US and in dozens of countries from which we import food.

This year the USDA provided several summaries in an effort to be clear about what they have found.  In this year's press release one finds the following, unambiguous statements:

The 2010 PDP report confirms that food does not pose a safety concern 

based upon pesticide residues.  

Statement from the EPA “The data confirms EPA’s success in phasing- out pesticides used in children’s food for safer pesticides and pest control techniques.  The very small amounts of pesticide residues found in the baby food samples were well below levels that are harmful to children.”  

Statement from FDA: "Based on the PDP data from this report, parents and 

caregivers can continue to feed infants their regular baby foods without being concerned about 

the possible presence of unlawful pesticide chemical residues." 

Statement from the USDA: "Age-old advice remains the same: eat more fruits and vegetables and wash them before you do so.  Health and nutrition experts encourage the consumption of fruits and vegetables in every meal as part of a healthy diet..."

Unambiguously positive assessments like this can also be found in the main data summary, the "What Consumers Should Know" highlights, and in the "Questions and Answers" link.

What Does The Press Tell Us?

As a typical example, CNN starts with the headline, "Watch out for the 2012 'Dirty Dozen," and continues, "Apples and celery are still agriculture's dirtiest pieces of produce according to the Environmental Working Groups annual "Dirty Dozen" report."  It's version of the baby food findings are, "For the first time this year, the USDA also collected data on pesticide residue in baby food, finding many of the studies samples to be contaminated with organophosphate pesticides."

How can CNN report something so radically different than what the USDA said?  They simply are repeating what the Environmental Working Group has said in its press release of 6/19 and make no effort to compare it with the official document.

HuffPost Healthy Living starts with the headline, "Dirty Dozen: EWG Reveals List of Pesticide-Heavy Fruits and Veggies."  Nowhere in this article is there even a reference to what the USDA, EPA and FDA said about the data.  It simply passes along the EWG interpretation as if it were gospel. 

This is the mainstream media.  You can well imagine what is said on various organic and Food Movement sites and blogs.

In contrast, Jon Hamilton writing for an NPR blog uses the headline, "Why you shouldn't panic about pesticide in produce."  Jon notes that the EWG sends a "mixed message," saying "you should be concerned about pesticide residues in fruits and vegetables, but not so concerned that you stop eating these foods."  Rather than simply parroting EWG, this writer demonstrates some journalistic mettle by interviewing a scientist at McGill University who can provide some perspective.  He also demonstrates that he read at least some of the USDA documentation by quoting specific numbers on apples and the non-alarm assessment for the baby food data.  Such efforts at balance are unfortunately rare.

Why Does The EWG's Version Get So Much Attention vs The USDA's?

Although sensationalism, low journalistic standards, and limited scientific background are certainly involved in the largely uncritical magnification of the EWG's message by the press (and particularly the blogosphere), I'm afraid that UDSA-AMS is partially to blame.  Don't get me wrong, they do a rigorous collection and analysis of the data.  They are extremely clear in what they conclude with sound reasoning.  They are definitely transparent and unbiased in their presentation.  What what USDA does not do is provide a summary version of the data that is easily digestible by ordinary readers, including typical members of the press.  EWG provides a simple list with a one dimensional ranking.  It is a gross and misleading simplification, but that makes it easy to relay as if it was a real analysis.  Unfortunately, the summaries that the USDA presents are extremely detailed, extremely long, and not easy to interpret even for someone who wants to.  Let me explain.

A Document That I Doubt Many People Really Read and Digest

The annual summary document for each year's PDP data is huge, in the range of 200 pages as a pdf (it is hard to tell, the appendices are numbered independently).  It starts with 28 pages of background on methodology and summary of sample types etc.  Then there are 9 pages of a historical appendix.  Finally the actual data begins in a 77 page appendix, but this is organized by chemical - nothing that most people would even begin to relate to.  For each chemical there is no information about whether that product is something toxic or not, nor is there information on any other dimension of its environmental profile.  To get that, someone would have to search for an MSDS and maybe an EPA RED - none of which are easy for any layman to interpret.  All this table lists are the number of samples, the number and percent of "detections,"  the range of those detections in PPM, the LOD (limit of detection), and the EPA tolerance (an extremely conservative level set by an elaborate risk analysis). Most people would have no idea what to do with those numbers.  In fact they show that the vast majority of "pesticide detections" are at levels well below the tolerances, but it is tedious to do the comparisons by eye and there is nothing in the table to give the message of how far below any level of concern the vast majority of samples are actually shown to be.  I'm not surprised that no independent journalistic interpretation of these data occur.

Below the chemical-by-chemical summary there are dozens of pages summarizing commodities other than fruits and vegetables.  That is followed by an appendix J which unhelpfully simply compares the "percent detections" for imported and domestic samples (a summary level as seriously unhelpful as that by the EWG).

Finally, at the very end of this huge document there is a crop-by-crop summary with the same data columns as for each chemical (#samples, #detections...) which has the same tedious requirement to compare detections and tolerance that are all usually numbers to several decimal points.  I have never seen anyone in the press do much if anything with this data set.

What Does This Report Need?

To be fair, USDA-AMS has amassed such a huge body of data.  It is difficult to summarize it in a way that is intuitively meaningful.  Their bottom line conclusion, "produce is safe," is a perfectly valid, but some visual representation could go a long way towards getting that message across.  I acknowledge that this is difficult.  I have made some attempts to do so in the past.  I plan to do so again with this year's data, but that will take time.  The same would be true for even an ambitious reporter, while simply reporting what the EWG says allows less ambitious reporters to keep up with the instant news cycle.

A Mountain of Data

It is a wonderful thing that the USDA makes the effort to analyze so many samples of so many crops and looks for so many different chemicals.  The downside is that this generates a database that is beyond what most of us even know how to process.  The file that one can download with the raw data has been getting bigger every year and has now reached 85MB.  I'm used to dealing with large files, but none of my ordinary software can deal this this.  I've gotten my son to write a program in RUBY to parse the data and only give me the tiny fraction which contains "detections" and discard the millions of rows of data that effectively say, "we didn't find this chemical in this sample."  I'm going to ask him to modify the program this year with some additional summaries.  

When and if I get this done, I plan to make this available to anyone interested in doing an actually meaningful analysis of the data and to explore ways to present it graphically in ways that can compete with the egregiously trivialized "analysis" done by EWG.  

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

Produce stand image from Steve Savage