Born and raised in Colorado, Cory Kreft began working on a honey farm at 15 years old. He returned to beekeeping after college, eventually buying the business from his former boss. But in 2021, his bees suddenly began dying. He lost 85 percent of his hives. The losses continued the next year, and the next. After extensive testing, he identified the culprit: a relatively new class of pesticides called neonicotinoids, often shortened to neonics. 

These chemicals are commonly used to coat crop seeds before planting, ostensibly to protect the plant from pests and insects during early growth. Thanks in part to a federal regulatory loophole, the use of neonic-treated seed has quietly exploded in recent years, with little regulation or oversight. Almost all conventional corn and more than half of soy seed in the U.S. is now treated with neonics. 

A legal loophole called the treated article exemption allows companies to apply these toxic chemicals to products like seeds without registering them separately as pesticide products. The seeds then fall into the same class as antimicrobial toothbrush coatings or treated lumber sold at major home improvement stores, with few legal limitations around how they are monitored, used, or disposed of. “Anyone can legally go buy this pesticide-treated seed, dump it in a river, and then contaminate the entire water system,” Kreft said.

Promised to be safer, but still toxic

Neonics were first introduced in the 1990s with the promise of being safer than older pesticides. “Neonics are neurotoxins, and they work by attacking critical parts of insects’ nervous systems,” says Jennifer Sass, a scientist with the Natural Resources Defense Council, or NRDC. The chemicals target neural receptors that are more common in insects than mammals. 

Neonics are systemic, so they move from treated seed into the tissues of the entire plant, including the pollen and nectar, and the fruits and vegetables that people eat. Manufacturers and government regulators claimed that these properties would make neonics relatively harmless to wildlife and people, and reduce soil and water contamination, since they claimed the pesticides would stay within the plant. 

Those claims didn’t hold up, says Sass, who has been researching pesticides for over 25 years. “They were supposed to be safe for people and wildlife. But none of that turned out to be true.” 

Since then, research has shown that neonics pose profound health risks for pollinators, ecosystems, and likely also people. The pesticides persist in the environment long after application and can travel via wind or waterways, contaminating ecosystems and communities miles away from where they were originally used. Overall, the amount of land treated with insecticide has continued to increase.

Research on seed coatings has found that they don’t typically help corn farmers’ bottom line either. Treated seeds have shown little or no impact on crop yield, so farmers are also paying more for unnecessary chemicals. Even so, pesticide-treated seeds have become so ubiquitous that it’s often hard for farmers to source untreated seed, and many use neonic pesticide-treated seed when they’re not needed. 

Neonics have become nearly impossible for pollinators and people to avoid. “They’re everywhere,” Kreft said, noting that he now buys food to place inside his hives during the summer months to keep the bees from foraging contaminated plant material. “They’re in the corn pollen in Colorado and the Midwest, and almond farmers in California are injecting neonics into their trees and putting them into irrigation systems. There’s absolutely nowhere we can go that our bees won’t be exposed to them.” 

When bees encounter neonic-contaminated pollen, the neurotoxin disrupts the neurological functions they rely on to navigate, forage, and survive. The hive then slowly declines and dies. “Over the last five years, we’ve seen between 60 to 85 percent hive mortality each year,” said Kreft. “It’s about a million dollars in losses for us annually.” 

The impacts of neonic pollution

The regulatory loopholes around neonics don’t end at the seed sales stage. They extend to disposal, too. Judy Wu-Smart, an entomologist at the University of Nebraska-Lincoln, has devoted her career to pollinator research. In 2017, she and her team made a disturbing discovery when they checked their beehives at a research site near Mead, Nebraska: The bees in every hive were dead. The pattern continued year after year. “We had almost 100 percent mortality from 2017 through 2020,” she said.

The team discovered that an ethanol plant called AltEn was operating near their research site. Major agrichemical companies use facilities like this to dispose of unpurchased seed before it spoils. The AltEn plant, Wu-Smart said, was processing much of North America’s surplus neonic-treated corn seed, contaminating surrounding ecosystems. Because neonic-treated seed is exempt from many rules that normally govern similar pesticide products, the facility was not subject to the same regulation and oversight as other pesticide disposal locations.

At the same time, residents in the nearby town of Mead began experiencing troubling developments: dead wildlife, sick family pets, and mysterious health problems. The seed disposal plant was selling ground-up pesticide-treated seed residue as a soil conditioner to nearby farms. Farmers were unknowingly applying high concentrations of neonicotinoids to their fields. 

After mounting scrutiny, the AltEn ethanol plant closed in 2021. But Wu-Smart notes that now, no one knows where excess neonic-treated seed is going for disposal. “It’s a big black box,” she said.

A growing push for stronger regulation

While the harm neonics inflict on pollinators is well documented, their effects on humans remain less certain. A recent study found that over 95 percent of pregnant women had neonics in their bodies. The chemicals have been linked to neurological, reproductive system, and developmental harms. Because neonics are now so widespread in food and water, Sass said, exposure has become nearly constant. “It’s everywhere now,” she said. “It’s in breast milk, tap water, even in baby food.”

Sass highlights research showing links to autism and learning disabilities among children from families living and working around farm chemicals like neonics. “I want people to understand that neurotoxic chemicals are bad for our brains, especially with fetal or early childhood exposure,” she said. “Early life exposure is more likely to cause permanent harm, much like lead or mercury.” 

Yet while research into human health effects continues, the regulatory gaps around neonic-treated seed are enormous. Wu-Smart said that when her bees were dying, neither state nor federal agencies could intervene, since there was no clear legal pesticide violation, like using a product in a way that contravenes its label instructions or other rules. Instead, the bees were being exposed through neonics that had spread into the surrounding environment — something current pesticide enforcement mechanisms were not designed to address. The same loopholes that allow treated seed to avoid full pesticide oversight also have created regulatory gaps around storage, disposal, contamination, and exposure well beyond the farm fields the pesticides are intended for.

Advocacy groups like NRDC have turned to state-level legislation. In Colorado, lawmakers recently considered the SEED Act, which would have expanded farmers’ access to seeds without insecticide coatings, while limiting unnecessary use.  The bill highlighted how a handful of major agribusiness companies have dominated the seed market, leaving many farmers with few options beyond chemically treated seeds. 

During the SEED Act hearings in the Colorado Senate, the act’s opponents argued that the legislation could increase costs and administrative burdens for farmers, while supporters highlighted the data showing limited benefits from pesticide-treated seeds and the evidence of the harm that neonics cause to pollinators and human health. They argued that the bill would protect pollinators, waterways, and public health, while also giving farmers more choice.

The act was ultimately defeated in Colorado, but similar laws have passed in New York and Vermont, and neonic regulation proposals have emerged in other states, including Minnesota, Massachusetts, and Hawaii.

Commonsense solutions

There’s an urgent need to close the gaps around neonic regulation by advocating for policies that limit unnecessary neonic use, expand seed options without harmful insecticides, and shift agriculture away from default chemical use. Since most neonic seed treatments are not actually needed to address pest problems, and typically provide no overall benefit, critics say that farmers should not be automatically using the pesticides. Instead, they propose a need-based model that preserves farmers’ ability to use treated seed when truly necessary, while restricting unnecessary use that spreads pollution. Quebec adopted this approach in 2019, with striking results: Neonic treatment for corn seed went from near universal to near zero in just a few years.

Those protections can’t come soon enough. In Mead, Nebraska, the environmental damage from neonic-treated seed did not end when the plant closed in 2021. Wu-Smart said that the pesticide contamination still lingers. “We’re still seeing high amounts of neonics in the honey from our hives in the area,” she said. “I wouldn’t eat it.” 

In Colorado, beekeeper Cory Kreft is not sure he can continue his honey farm. “There’s so much work that goes into beekeeping,” he said. “If I can’t keep my bees alive because this pesticide is everywhere, why would I keep doing this?”