Pesticide Reduction: A Goal For American Agriculture

“Our goal as a community is to reduce the amount of pesticides used in agriculture,” explains Cornell scientist Anthony Shelton in a mid-2015 New York Times article on why he wants to release genetically engineered diamond-back moths into New York State cabbage fields. The moths are now controlled with chemical pesticides, which Shelton hopes would become unnecessary if releases of sterile insects cause moth populations to plummet. 

This rationale for genetic engineering is nothing new. Proponents of biotechnology have long touted pesticide reduction as a benefit of their products. This enthusiasm of the biotechnology industry might suggest that pesticide reduction is a broadly shared goal in United States agriculture. But is it? 

Outside of the biotechnology industry trying to promote its products, not many in mainstream agriculture give high priority to pesticide reduction. This is hardly surprising in that pesticide manufacturers, a category that includes many biotechnology companies, dominate the agricultural establishment. Even among biotechnology proponents, pesticide reduction is a goal—until it isn’t. Industry supporters rarely criticize the herbicide-tolerant crops, although they are now associated with sharply increased pesticide use due to the evolution of resistant weeds.

Pesticide Reduction Should Be A Policy Goal

The biotechnology proponents’ first impulse is a good one. Pesticide reduction should be a policy goal of United States agriculture. 

Why should we reduce pesticide use?

Pesticides are potent toxins, designed to kill organisms across the biological spectrum. Many of them emerged from research on chemical warfare. We use pesticides for good reasons: to control weeds, insects, rodents, and other pests. But given their origin, toxicity, and broad—even profligate—application, their risks should be presumed. We should use such chemicals sparingly and constantly move toward more modern, non-chemical options for controlling pests. Such methods are already available, profitable, and provide multiple benefits such as cleaner water, in addition to pesticide reduction.

But that is not the government's approach. The government charges regulators with determining the threshold levels of pesticide that are legally acceptable in foods and in the environment, and as long as pesticides are used below those levels, doesn't seek further reductions. This might make sense if regulators could set and enforce genuinely protective thresholds, but that is not the case.

Flawed regulatory schemes have led to a passive, albeit legal, poisoning of the environment that we should no longer accept. A more scientifically rational approach would be to actively encourage pesticide use reduction, even of the approved pesticides.

Regulatory Systems Are Not Sufficiently Protective

Very roughly, the basic structure of pesticide regulation envisions regulators assessing the dangers of toxic chemicals and then deciding whether those risks are reasonable in light of the benefits of use. Sounds simple. But in practice, determining safe levels of pesticides is immensely complex in agriculture, where pesticides are used in large quantities over huge acreages in all kinds of environments. Under our system, where the burden of proof is key, complexity favors pesticide manufacturers.

Importantly, pesticide regulators’ major scientific tools—risk assessments—are notoriously imprecise. They depend on hard-to-obtain input data and are shot through with judgments and assumptions. All that wiggle room makes risk assessments susceptible to non-scientific influence.

Also, shortcuts in the regulatory systems such as conditional registrations allow pesticides to get on and stay on the market despite big gaps in the data submitted to Environmental Protection Agency (EPA). The missing data, mind you, include precisely those that the EPA needs to assess risks and make informed decisions. Lapses in enforcement also undercut the effectiveness of pesticide regulation.

Neonics Illustrate the Weakness of Regulation

A stunning example of the inadequacy of regulation to control pesticide use is the case of the neonicotinoids (“neonics”). Neonics are a class of neurotoxins that are now among the world’s most popular insecticides. While there is controversy and much research remains to be done, widespread use of neonics is now understood to plausibly threaten a global environmental crisis.

The deaths of honeybees and other pollinators are the most visible evidence of the effects of these chemicals, but that is just the beginning. Neonics can also kill vital invertebrate organisms found in water and soils. They threaten birds, both directly and as consumers of contaminated invertebrates, and are a toxic blow to Monarch butterflies, already decimated by the loss of milkweed from fields planted with glyphosate-tolerant crops.

As an environmental threat, neonics hit the trifecta:

  1. They are active at exquisitely low concentrations—a single corn kernel coated with a neonic can kill a songbird.
  2. They are widely used—according to the Center for Food Safety's Water Hazard report, neonic insecticides are found on 150 million acres annually, about one-twelfth the of the area of the contiguous U.S.
  3. They can persist in the environment for a year or more.

The evidence of harm has been building since the mid-1990s, shortly after the neonics were first approved, but the U.S. government has only recently—after 15 years—begun to stir.

The neonic case illustrates how complex science and procedural options, such as conditional registrations, can lead to unconscionable foot-dragging. Regulators should have acted earlier and need to take important steps right now to address this crisis. Similar scientific and structural flaws apply to the regulation of many pesticides, including glyphosate, atrazine, or 2,4 D.

But the neonic situation has even broader implications: it shows the futility of relying on regulation as the sole control on pesticide use. Even at their best, regulatory schemes are not up to the task of protecting the environment from pesticides. Given the complexities of the science and the industry bias within regulatory bureaucracies, pesticide regulation routinely allows higher-than-necessary amounts of chemicals in the environment.

Set Pesticide Reduction as a National Policy Goal

We should add another lane to the highway for rational pesticide oversight—I suggest that we begin by setting pesticide reduction as a national policy goal, even of approved products.

If reducing pesticide use were adopted as a national goal, policy leaders could begin to use non-regulatory levers to create incentives for pesticide reduction. They could factor the potential for pesticide reduction into research priorities and consider durable pesticide reduction in decisions to deregulate genetically engineered crops. They might establish fellowships in non-chemical pest management or sponsor field days where farmers can share successful strategies for using fewer pesticides.

Perhaps the government could set a quantitative national goal for pesticide reduction—say 25 percent over five years—and devise a multifaceted program to meet that goal.

These and other ideas could help us sharply reduce the use of chemical pesticides, making them the last resort rather than the ordinary course of business. At a minimum, setting pesticide reduction as a goal would help make explicit what the neonic case underscores: pesticides are a class of chemicals so dangerous that as a general proposition, fewer are better.

Our present practice of using ever more pesticides, while evidence of harm slowly accumulates, poses an unacceptable threat to honeybees, monarchs, and many other creatures, including ourselves. Pesticide reduction should be more than a public relations tool for selling GE products. It should be a linchpin of U.S. agricultural policy.

Margaret Mellon is a science policy consultant.

See also:
We Must Save The Honeybees And Here’s How You Can Help
EPA Confirms Longstanding Fears About Impact Of Neonics On Bees