The Risky Business of Pesticides
Dr. Jonathan Lundgren
It is easy for a farmer to justify applying a pesticide to their field. “Margins are thin, and pesticides are too cheap not to apply.” “The guy down the road lost an entire field last year to armyworms.” “The co-op will put it on for me, so that I don’t have to worry about it.” “Just put some insecticide in the tank when you spray the fungicide; it will be an insurance against anything bad happening.”
The first problem with this is that there is no perceived consequence for using agrichemicals. If farmers (or beekeepers or homeowners, etc.) can purchase a product, and it has all of its safety information on the side of the jug, then it is generally assumed somebody is watching and the chemical is safe. Safe both for the environment and humans.
The second problem is scale. Outcomes of decisions made on individual farms spillover to neighbors, begin to aggregate and swell across landscapes and regions as farming communities unify in their decision to apply an agrichemical, be it fertilizer, insecticide, herbicide, fungicide, etc. The amplification of these decisions substantially heightens the degree of risk posed by an agrichemical.
The unforeseen risk of pesticides
I started my career as a graduate student working on risk assessment of genetically modified Bt corn. This was a new technology that changed how we managed pests. A gene from an insect disease called Bacillus thuringiensis (Bt) is inserted into corn plants, defending it from key pests like European corn borer and corn rootworm. It was my PhD dissertation to assess the risk of beetle-specific Bt corn events against beneficial beetles; predatory lady beetles, specifically.
Try as we might, we really struggled to find an adverse effect of one type of commercial Bt corn on my lady beetles. And we published that there were no adverse effects of Bt corn on lady beetles.
However, since Bt corn was first commercialized, insect populations and diversity have plummeted in many places on earth, while insecticide use continues to rise in North America. Farmer profitability has diminished. And pollution continues to rise.
Thus, I would argue that the real environmental risk posed by Bt corn was never its toxicology (although GM crop varieties may have some physiological changes that make them different from conventional varieties). Instead, the biggest risk posed by Bt corn is that it changed agriculture in ways that supported the simplification of landscapes. Allowing farmers to grow corn year after year (pests normally helped to drive crop rotation). The implications of this simplification for biodiversity loss and the resilience of farms is now pretty evident.
But how could we have predicted this risk and evaluated it prior to the release of this technology?
Risk assessment is completely constrained by a very narrow set of questions. So a product can be deemed safe until we ask the right question or the technology is available to actually perceive the risk that is posed. Often times, the risk posed isn’t fully understood for decades after it is released into the environment (e.g., DDT was deemed safe by the best technologies of the day).
Context matters for risk assessment
The scale of an environmental exposure affects the degree of risk that is posed. It is easy for a farmer to think that the decisions on their farm are siloed. That the consequences of decisions made on a farm are somehow contained. But when decisions made over a watershed or region are examined in aggregate, it is easy to see how our food production system can influence bigger things like climate change, or society-wide human health issues, or pollutants in the Ogallala aquifer or the Gulf of Mexico.
Risk assessments are usually made based on data generated in a petri dish. But when an organism is in the real-world, the risk scenario changes substantially. There are all kinds of other stressors an organism faces in the environment that affect its susceptibility to a pesticide. First of all, organisms are never exposed to just the active toxic ingredient (a.i.). The a.i. is always combined in a formulation, which changes its’ toxicity. But toxicity assays are almost always done on the a.i. alone. In the field, a honey bee might be hungry, or too hot or cold, or it may have just been nailed by a fungicide, or exhausted from flying for miles. Data generated in the laboratory are frequently an inapt representation of field populations of an organism.
Science on risk can be manipulated
Some pesticide companies do not play fair, and there is a strong motivation for them to preserve their technologies. When you consider the sheer acreage that corn represents, the potential profits that are generated are staggering. For general purposes, let’s assume that a genetically modified bag of corn is $100 more than a conventional hybrid (this is probably an underestimate), and it takes 1 bag of corn to plant 2 acres. 92% of corn acres were genetically modified in 2018, and we planted 89 million acres. That means that revenues from genetically modified corn seeds could conservatively be estimated at around $4.1 billion annually, just for corn. Neonicotinoid seed treatments were initially assessed as $10 per acre for corn; this accumulates $410 million dollars revenues annually from corn, since nearly all of the nation’s acres of this crop are treated with this insecticide (unnecessarily, in almost all cases).
So how would a company influence the dialogue regarding pesticide science?
There is no such thing as a perfect research study, and when a study comes out that provides inconvenient data regarding a product or agenda, then it isn’t hard to discredit a study by pointing out its deficiencies.
If there are problems with every study, then how is science useful for decision making? Decision makers rely on a preponderance of evidence; repeating a study multiple times, and looking at the resulting pattern in the data. But science is for sale, and the discussion can be influenced when companies fund research that suggest that alternative explanations may be causing the problems actually resulting from pesticide exposures.
Finally, the scientific dialogue is controlled when scientists that persist in conducting research on controversial topics are publicly destroyed for any of a number of reasons. There is no incentive for conducting controversial research; scientists get paid the same whether they count lady beetle spots or investigate risks of pesticides. But they and many they care about may keep their job longer if they focus on something safe, like counting the lady beetle spots.
With the stakes as high as they are, the relative investment in preserving the life of a product for even one more year is often incentivized and justifiable to a company. For example, a $2 million center that points out all of the ways apart from pesticides that bees are dying is a small investment for a company generating these sorts of profits. Or annual gifts of $20,000 to key scientists at universities across the country as a good will gesture or to generate data that distorts the discussion on agrichemicals is a good business decision.
The final word
When I began my career, I foolishly believed that we could predict the risk of pesticides. After conducting risk assessments for 20 years, I can attest to two truths. First, we cannot predict the environmental effects of a pesticide in complex natural systems. And second, nobody is watching the safety of agrichemicals. I am not saying that we should ban pesticides. But I encourage farmers to recognize there are consequences of pesticides that extend beyond the fence lines of their farms and we cannot see all ends in a risk assessment scenario. Respect these chemicals, and only use them as a last resort. It is an expense, after all.
Dr. Jonathan Lundgren
Director of the Ecdysis Foundation (a 501.c.3)
Owner of Blue Dasher Farm
Estelline, SD, USA, 57234