Pesticide Politics

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Pesticides freak us out – and understandably so. The idea of otherwise healthy fruits and vegetables marred by residual poison unnerves us because, generally speaking, we’re clueless. We’re totally removed from the process of production. We don’t know what was sprayed, we can’t see the trace pesticides, we can’t measure them on our own, and, let’s face it, the vast majority of us don’t remotely understand how these agents work.? The upshot is that we’re left to trust outside interpreters to assess the risk for us.

And this, as a recently hatched debate reminds us, can be equally unnerving. Earlier this month, 50 environmental organizations got together and demanded that California return a $180,000 federal grant awarded to the Alliance for Food and Farming, an agricultural non-profit based in Watsonville, CA. The AFF received the grant, in its own words, “to correct misconceptions that some produce items contain excessive amounts of pesticide residues.” The protesting organizations – notably the Environmental Working Group and the Organic Consumers Association – claimed that such a mission “strikes a blow” at the organic movement, adding that “it is inappropriate for state and federal officials to categorically take the side of conventional agribusiness in this scientific and policy debate.”

At the center of this emerging food fight is a popular pamphlet that the EWG has been publishing for years called the “Shoppers Guide to Pesticides.” In it, the EWG reports results of tests conducted for pesticide traces on 49 fruits and vegetables (conducted by the USDA and FDA). The takeaway from these high profile reports – the part that goes viral on the web and captures the headlines – is a list of the 12 most “contaminated” foods. This year’s “Dirty Dozen” includes blueberries, peaches, strawberries, kale and spinach. These are some of the healthiest foods that our good earth yields, but the EWG advises that you “can lower your pesticide consumption by nearly four-fifths by avoiding the 12 most contaminated fruits and vegetables.”

The Alliance for Food and Farming finds this suggestion to be counterproductive. Drawing on a study conducted by five scientific experts (which it commissioned), the AFF in no way denies that certain foods contain trace pesticides. Instead, it contends that exposure isn’t the same as toxicity. The Dirty Dozen, it explains, “is misleading to consumers in that it is based only upon exposure data while remaining silent about available information on the assessment of the toxicity.”

Public-relations wise, the AFF is in a tough spot. Taking a position that tolerates pesticides hardly attracts throngs of happy supporters.? From a scientific perspective, however, the AFF seems to be on solid ground.? The EWG report cites not a single study to support a direct link between pesticide residue and health defects. In fact, it openly admits that “the EWG’s shopping guide is not built on a complex assessment of pesticide risks.” But then it refers to some pesticides that are “linked to brain and nervous system toxicity” and others that are “linked to cancer.” All of which raises the confounding question: what do we mean by “linked”? Directly linked? Or linked in the way that the flap of a butterfly’s wings is linked to a monsoon on the other side of the world?

Easily missed in all the linguistic ambiguity is the well substantiated fact that a diet rich in fruits and vegetables – organic or not – is healthier than a diet lacking in these foods. “The consumption of fruit and vegetable-rich diets,” the AFF explains (citing several peer-reviewed studies), “is associated with a reduced risk for high blood pressure, reduced risk for heart disease, stroke, and probably some cancers.”

What apparently worries the AFF is that consumers who know they should be eating more fruits and veggies (but are unwilling to pay twice as much for organic) will use the documented presence of pesticide residues as a convenient excuse to avoid eating more fruits and veggies. In this sense, the EWG’s implied health threat is obscuring an important question: could the density and variety of nutrients in plant foods far outweigh whatever possible health defects are caused by ingesting trace amounts of pesticide residue?

As critical as this question is, it cannot be answered with complete certainty. After all, it’s impossible to assert with 100 percent confidence that a particular chemical doesn’t cause cancer, especially when so many agents do cause problems if delivered to lab rats in high doses. Still, to use the premise that certain pesticides could cause harm in order to dissuade consumers from eating conventional produce fails to consider several basic countervailing points, all of them summarized in the AFF-sponsored rebuttal.

First, the vast majority (as in 99+ percent) of the dietary pesticides we eat are natural. Plants have evolved their own chemical defenses. Many of these natural pesticides are equally, if not more, carcinogenic than their synthetic counterparts. Dr. Bruce Ames, the Berkeley biochemist who has dedicated a lifetime of research to carcinogens and aging, has famously noted that we ingest more carcinogens from a cup of coffee than from a year’s worth of conventional produce. “People got it in their head [that] if it’s man-made somehow it’s potentially dangerous, but if it’s natural it isn’t,” Ames groused to Reason magazine. “That doesn’t really fit with anything we know about toxicology.”

Second, although it’s de riguer to dismiss regulatory agencies, the EPA’s guidelines for assessing the risks of residues are impressive.? Cancer risk is judged according to a one in a million “acceptable risk level,” while a 10-fold safety factor is applied when establishing acceptable levels of residue for infants, children and fetuses.? The USDA’s monitoring of residues finds very, very few cases of over-exposure. In 2007, over 11,000 sample tests detected residue exceeding legal limits in only .4 percent of the cases.? Moreover, legal exposure levels are ten times lower than levels known to have negative effects on animals, meaning that even the .4 percent was probably relatively innocuous.

Finally, the evidence is mixed at best that eating organic – the one alternative that avoids synthetic residues – is any healthier than eating conventional.? In a way, such a comparison is of limited value – the nutritive quality of plants can vary according to an indefinite number of factors (which may or may not be linked to organic or conventional production). That said, the Institute of Food Technologies observed in 2006 that “pesticide residues, naturally occurring toxins, nitrates, and polyphenolic compounds exert their health risks or benefits on a dose-related basis, and data do not yet exist to ascertain whether the difference in the levels of such chemicals between organic foods and conventional foods are of biological significance.”

At this point, it’s worth returning to the original objection to the AFF’s relatively small grant. The fifty groups opposed to the FAA insisted that “it is inappropriate for state and federal officials to categorically take the side of conventional agribusiness.” I understand the concerns with industrial agriculture. But – given the unresolved complexity of the matter – are there even sides to take? Isn’t it the science that we should be concerned about? Rather than bicker over whether or not agribusiness is currying undo favor, shouldn’t we be asking our expert gatekeepers to objectively discern whether or not I should be eating the handful of conventional blueberries I consume every morning? Or has the politics of food gone so far down the rabbit hole of interest politics that we’re all doomed to make our dietary choices in complete darkness?


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"undue favor"?

Susannah Stevens

One factor that the author does not mention, and that the EPA and FDA's tests fail to take into account, is the combined total effects of all the pesticides and other carcinogenic chemicals we ingest, inhale, or absorb throughout our lives. These safety tests are done in isolation. The fact that one can safely consume one pesticide at amounts that are greater than you're likely to get from your daily fruits and vegetables does not necessarily mean that the total load of various pesticides in all our food is safe. And that's not even considering the wear and tear on our bodies from indoor pollution and conventional cosmetics, to name a couple. How are we to know that these pesticides won't tip the balance in an already stressed system and cause cancer or soemthing else?

Drill-Baby-Drill Drill Team

People complain of the invisible tasteless pesticide residuals in produce.
But how would they feel to have a slug in their brocoli, a worm tunnelling in their tomato, a snail in their mesculun argula mix, a box of apples with a colony of locust, a stink bug in their potatoe, or a larva in their banana?
The Organic people say this is natural, and perhaps we all could deal with a little more insect protein...think of it as a 'land shrimp.'

Everything is a tradeoff. Nothing is an unqulaified good...Welcome to the World of Real Economics.


How about the fact that pesticide is poison. And let's move beyond our human centered mindset for a moment... we are dumping poisons all over the planet. It is the height of arrogance and/or denial to think this could be okay.


I also find it funny that people deny natural pesticides in plants. That "fresh green smell" from cucumber is a pesticide--the cucumber genome project paper showed that. Alfalfa has one--a PLoS paper has that information. Should people avoid those? Personally I eat alfalfa sprouts anyway.

And it's also amusing to me that people know that chocolate could kill their dog. But they still eat it....Go figure.


I agree that the point should be to develop the science objectively and improve our ability to understand the risks and benefits of conventional produce. But the AFF's mission that you quoted isn't objective - it's to prove that the pesticide residues are ok: "to correct misconceptions that some produce items contain excessive amounts of pesticide residues."

I think that is problematic in that the AFF has chosen a side and is just looking to support it; that's not objective. If the mission were "to evaluate whether pesticide residues pose excessive risk," that would be different.

I also think that there's another layer of complexity to the pesticide issue that's not discussed here. It's not just that there's only a choice between super-expensive organics and pesticide-laden but cheaper conventionals. There are different types of pesticides with different levels of toxicity, and there are lower pesticide growing methods. And there's a type of inertia - sometimes we don't develop or pursue less dangerous alternatives simply because there's no reason to - sometimes it's not until a chemical is banned that we discover that there are in fact cost-effective and less toxic alternatives. I honestly don't know how you incorporate all those factors into a risk analysis, and how you account for the potential costs of inertia.



The point well made in this article is that we are not the only ones dumping poisons. Every species does it. It is foolishness, if not arrogance, to automatically assume that a well-studied man-made pesticide is necessarily worse than a natural pesticide (the ones plants have evolved for their defense). Yes, there is a higher likelihood that our species will have evolved defenses against natural pesticides we encounter over millions of years, but hysteria about pesticides combined with the assumption that natural poisons are safe is mindless.

Just one example, the toxins in green spots on potatoes are almost certainly worse than tiny residues of man-made pesticides on them. We can deal with both.


Great article. Note that 'organic' food production is a subset of the 'sustainability' movement. There's little evidence that organic food has individual health benefits, but when we need to consider that there are costs incurred with current agribusiness practices that present problems that need to be solved. Instead of getting my garlic up the road in Gilroy, it's 'cheaper' to have it shipped from China on boats powered by toxic bunker fuel from Venezuela, puts Gilroy garlic farmers out of business, and undercuts our collective standard of living and quality of life. Let's cut the visceral and thoughtless 'sustainability is anti-business' reaction and use our resources to find workable solutions that balance cost, profit, health, and quality. We can do better.


@Mary - theobromine (found in chocolate) in normal quantities is only toxic to dogs because they are slow to metabolize it. It's the plant's alkaloid which is toxic. It is not a pesticide. And when Ames says there's 17 carcinogens in coffee, he should be more specific.

James L

Our trusty gov used to say lead paint was safe too.

I wonder how AFF will feel when we find out these pesticides were actually harmful. Chemicals are chemicals and the more you eat, the greater risk you have of getting sick.

As for a bug in a box of produce, big deal...

If you live around the farms in California that use these pesticides, be sure to serve your kids up a big tall glass of tap water tonight.

I believe in letting the consumer decide. If AFF felt the same they would also put a link to the wikipedia description of each toxic substance on their site.

This is clearly a campaign to promote a slowly withering industry. Ask your local consumer if they'd like an organic or pesticide piece of produce.

Organic, buying/growing local, farmers markets are here to stay. Sorry AFF, not even a smear campaign against EWG can stop it.


@Jim: good point on potatoes. In fact, conventional breeding of some heirlooms created a potato that had way too high levels of that toxin and had to be pulled from the market.

Organic pesticides also kill things. By design.


There seems to be the assumption that organic produce is pesticide free. This is not the case. Organic methods simply shorten the list of pesticides that can be used.

Has anyone looked scientifically at whether the "grandfathered" pesticides used in organic farming are more or less dangerous than the more modern ones used in free-style farming?


Re #3: "And that's not even considering the wear and tear on our bodies from indoor pollution and conventional cosmetics..."

So why not spend more time outdoors, and use fewer cosmetics?

As for the organic vs pesticide debate, I think almost everyone has missed the boat. The reason I buy (or grow, when I can) organic varieties of fruits and vegetables isn't a concern over pesticides, it's simply because it's the only way to get good-tasting varieties these days. Real sweet corn has been replaced, in the mainstream markets, with that horrible white "Super-sweet" junk, good apples like Rome, Jonathan, and MacIntosh (to say nothing of classics like Cox's Orange Pippin) have given way to newer kinds with all the edibility of sweetened balsa wood, other fruits are plumped up with gibberellins 'til they're all water and no flavor...


The government is famous for taking the side of Big Agribusiness. Just look at the USDA's partiality toward the meat and dairy industry in the old food pyramid (now it's corn). And if a farm wants to be USDA certified organic, they pay a fee. Besides which, it's not cancer I'd be concerned about. I'd be more worried about Parkinson's caused by the pesticides.

Ironically, these pesticides are ingested by insects, who do not die instantly. They fly around long enough to be ingested by insect-eating birds.

The guam's swiftlet population is harmed by pesticides, as are other swifts and swallows. These birds keep the insect population under control. By killing off these birds, we may be creating a rebound affect which is just shooting ourselves in the foot. And decimating our birds.

Now we have the charming development that these insect populations are not only rebounding, but becoming resistent to pesticides as well.



@Emmi: so you are saying species differences and dosages are important to understand toxic chemicals in plants....well, what do you know....

And Ames was very specific about the coffee toxins, and many others. If you were familiar with his peer-reviewed papers and publications in major respected journals you would know that.

Such as: Dietary pesticides (99.99% all natural)

Or: Ranking possible carcinogenic hazards

Don't feel bad, it's not easy to keep up with the science over the decades.



Most agrochemicals are very specifically targeted at insects. Pyrethroids, carbamates and organophosphate pesticides are effective because they have very low human toxicity and very high insect toxicity.

Furthermore, residue and other studies demonstrate the persistence of these chemicals in the environment, and any pesticide with long persistence will be approved by the EPA at a safe, low application rate.

Thus, most agrochemicals are not around all that long in the environment, and while they are around they are essentially only toxic to insects.

Joel K.

Two issues with this post:

1. Mr. McWilliams implies that if consumers don't eat convential produce which are on the "dirty 12" list, their alternatives are to either eat unhealthy food or expensive organic produce. This is a false choice. There are plenty of other conventionally grown fruits and vegetables that are not on the dirty 12 list.

2. Not considered in the choice between organic and conventional produce are other negative externalities associated with pesticides. Risk to immediate health is one consideration in the analysis. What are the long-term risks of using pesticides to generations of farmers and consumers?

Tom Pestak

We should replace all agriculture with organic only, pesticide-free, genetically unmodified, locally-grown, farmers market food. Only original species of plants too - nothing that was cross-bred. We could cut down every tree in North America to make room for all the land we would need, we could cultivate with our hands so as not to be carbon neutral, everyone could just grow food, and we could trade it at our local markets while being protected from outsiders by our authoritarian leaders.

Wait, did I just described feudalism + massive starvation? Or the enviro-friendly "green" agenda?


Many good comments so far, especially #7's points about inertia and the AFF study having a preset non-objective agenda.

I'm also concerned about limiting any examination of pesticide use to just measuring residues on produce. Of course the broader issues are harder to study, but they're at least as important. For starters:
-cumulative effects of toxins on the body
-chemical exposure of farmworkers
-chemical runoff into streams and ground water
-the rate at which insects develop pesticide-resistance

And then there's the business model of pesticide manufacturers, which is to encourage the maximum use of their product, rather than the minimum.