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?