New Pesticides Will Modify Insect Genes: What Could Go Wrong?

These pesticides will broadcast “gene silencing” agents across our farm fields — resulting in an open-air genetic engineering experiment. Among the concerns that scientists have raised are threats to bees and other beneficial insects essential to food production. Others have called out potential impacts on human health, including for some of our most essential frontline workers — farmworkers — and rural communities.

Farmers across the U.S. could soon fill their pesticide spray tanks with a substance known as interfering RNA (RNAi). (RNA is a molecule similar to DNA.) Insects that are exposed to it — either by eating crops sprayed with the substance or by landing on a crop and absorbing it through their bodies — would be genetically modified right there in the field. The pesticide would trigger a process inside the insects’ cells to switch off or “silence” genes that are essential for survival — like those needed to make new, healthy cells — thus killing them.

At least one product has already been submitted to the Environmental Protection Agency for approval. But unless Biden’s administration takes action, companies will be able to commercialize these new RNAi pesticides without submitting meaningful health or environmental risk assessments.

The U.S. Environmental Protection Agency’s pesticide rules were written fifty years ago, long before regulators could imagine a class of pesticides that could genetically modify living organisms. Perhaps most concerning is that once gene-silencing agents are released into the environment, there’s no clean-up process when things go awry. Evidence shows that RNAi-related genetic modifications could be passed on for up to 80 generations in some cases.

What could go wrong? Quite a bit, according to scientific research summarized in a report from Friends of the Earth.

RNAi and the “Insect Apocalypse”

There is little reason to believe that this novel technology would be able to target only the “bad” insects and not the plethora of insects that are vital to farming, like pollinators. Bayer and other companies developing RNAi pesticides assert that they can target specific insects. But the genetic story of an ecosystem is one of interconnection — independent researchers warn that thousands of insect species have genetic sequences that are matching or similar enough that they could be unintentionally modified in a way that results in their death.

A 2017 study indicating that honeybees could be harmed by RNAi pesticides raises a red flag since we rely on pollinators for one in three bites of food we eat. Insects form the basis of the food webs that sustain all life on the planet. We are already in the midst of what scientists call an “insect apocalypse” — forty percent of insect species face extinction in coming decades. This is a loss so severe that it could cause a “catastrophic collapse of nature’s ecosystems” according to leading researchers.

Health Concerns

It’s not just insects that may be harmed. While there are gaping holes in the research about potential human health impacts, what we do know raises concerns. Research indicates that naturally occurring RNAi that we consume in our food could regulate genes in our bodies. This suggests that synthetic RNAi could affect our gene expression, causing unforeseen problems. And medical research investigating therapeutic uses of RNAi has been hampered because some participants in clinical trials have experienced adverse immune reactions in their bodies.

Entrenching a Failed Paradigm

The pesticide industry is pitching RNAi pesticides as a solution to a problem the industry itself created: weed and pest resistance. As Rachel Carson warned in Silent Spring, her groundbreaking book about pesticides in the 1960s, our “relentless war” on insect life will inevitably fail because nature “fights back.” Indeed, over 540 species of insects and over 360 types of weeds have evolved to resist the deadly effects of commonly used pesticides. Despite drastic and costly increases in pesticide use, some analyses show that farmers are losing more of their crops to pests today than they did in the 1940s.

It is foolish to continue down this same path and expect a different outcome. Research already shows the potential for pests to develop resistance to RNAi pesticides.

But pesticide giants like Bayer and Syngenta need new products to sell. A significant portion of their income is tied to pesticides that pose serious hazards to health and the environment. And as the scientific evidence mounts, the industry is facing increasing regulatory, legal, and market pressures.

Not only could RNAi pesticides provide a lucrative new suite of products, companies appear to be using them to extend their ownership over nature in an unprecedented way. Manufacturers are filing patents that claim property rights to the organisms exposed to RNAi pesticides as well as to their progeny.

Farming With Nature — a True Solution

The science shows clearly that pesticide-intensive agriculture is a disastrous dead end. Decades of data point to the same conclusion: we must rapidly shift to ecological farming methods in order to continue to produce food for generations to come.

Ecological farming offers a true solution to pest management with additional benefits. Practices like cover cropping, composting, and rotating crops build healthy soils that strengthen plants’ defenses against pests and fungi while disrupting pest cycles and fostering biodiversity. These same methods, which underpin the success of organic farming, are also the lynchpins of regenerative agriculture, the idea that farmland can serve as a carbon sink.

Follow the Science

Biden has already signaled that he is likely to shy away from making the bold changes we need by appointing Tom Vilsack as head of the U.S. Department of Agriculture (USDA).

But as he rebuilds the scientific backbone of the federal government, advocates hope that he will take steps to update our decades-old pesticide regulations, such as those outlined in this recently introduced bill. In addition, specific criteria need to be added to ensure a science-based approach to regulating RNAi pesticides. Risk assessments of this novel technology should include genome analyses of beneficial organisms in the regions where they will be sprayed to see if bees and other critical species could be harmed, assessments of the hereditary impacts across generations of organisms, evaluations of how long the pesticides will remain active in ecosystems, and rigorous toxicity analysis to understand potential impacts on human health.

If Biden’s EPA does not take these measures, we will soon embark on an open-air genetic experiment, the consequences of which may be felt for generations to come.