Neonicotinoids & Glyphosate: Pesticides Threatening Pollinators and Public Health

Two of the most widely used pesticides in the United States — neonicotinoids and glyphosate — pose serious risks to pollinators, ecosystems, and human health. These chemicals are pervasive in agriculture and the environment, contaminating soil, water, and food.

What Are Neonicotinoids?

Neonicotinoids (often called “neonics”) are a class of systemic insecticides designed to protect crops from insect pests. Because they are systemic, the chemicals are absorbed into the plant’s tissues — including pollen and nectar — exposing bees and other pollinators.

Neonics are one of the most toxic pesticides to bees, and are a leading cause of pollinator and insect declines. Even low levels of exposure can impair bees’ foraging and navigation abilities. They disrupt learning, communication, and learning for bees. And they suppress immune systems, making bees more susceptible to pathogens and parasites.

Neonics are now among the most commonly used insecticides in the country — used on more than 140 crops and at least 150 million acres across the US. They are applied to seeds, sprayed on crops, and used in landscaping products.

The vast majority of use is as seed coatings on commodity crops like corn and soy. Neonic seed coatings provide virtually no benefits to farmers and, in some, cases common neonic treatments can actually decrease crop yields by killing pollinators.

Why Are Neonicotinoids Harmful?

Research links neonicotinoids to:

• Bee deaths and colony collapse
• Harm to butterflies and other beneficial insects
• Declines in bird populations
• Contamination of waterways

Even small amounts can impair bees’ ability to forage, navigate, and reproduce. Because these chemicals persist in the environment, their impacts extend far beyond the fields where they are applied.

US agriculture has become 48 times more toxic to pollinators and other insects since use of neonicotinoids began.

What Is Glyphosate?

Glyphosate is the active ingredient in the herbicide Roundup used to kill weeds in agriculture, landscaping, and home gardens. It is the most heavily used herbicide in the world.

Glyphosate is commonly used in conjunction with genetically engineered crops that are designed to tolerate the chemical, allowing farmers to spray fields without killing the crop itself.

Why Is Glyphosate a Concern?

Scientific studies associate glyphosate exposure with:

• Probable cancer risks
• High rates of kidney disease and shortened pregnancy
• Harm to soil organisms and aquatic life
• Loss of habitat for pollinators, including monarch butterflies

Widespread use has led to contamination of food and water supplies. The chemical’s broad application increases the likelihood of human exposure.

Pesticides and Pollinator Decline

Pollinators — including bees, butterflies, and other insects — are essential to food production and ecosystem health. Many crops depend on pollination, and wild plants rely on pollinators to reproduce.

Neonicotinoids directly poison pollinators. Glyphosate contributes indirectly by destroying flowering plants and habitat that pollinators depend on.

Neonics are one of the most toxic pesticides to bees, and are a leading cause of pollinator and insect declines. Even low levels of exposure can impair bees’ foraging and navigation abilities. They disrupt learning, communication, and learning for bees. And they suppress immune systems, making bees more susceptible to pathogens and parasites.

Pollinators are not the only species affected. Neonics harm many species essential for natural pest control and sustainable food production, including birds, bats, butterflies, ladybugs, earthworms, small mammals, amphibians, and more.

Glyphosate is decimating Monarch butterfly populations. Glyphosate usage has virtually destroyed the milkweed plants that young Monarch butterflies depend on. The pesticide can also disrupt honeybee gut microbiomes, linking the herbicide to honeybee decline.

The combined impact of these pesticides is driving pollinator decline and threatens biodiversity.

Environmental Contamination

Both neonicotinoids and glyphosate are persistent in the environment. They can:

• Leach into groundwater
• Run off into streams and rivers
• Remain in soil for extended periods

This contamination affects aquatic insects, birds, and other wildlife, disrupting entire ecosystems.

Human Health Impacts

Both neonicotinoids and glyphosate are links to human health harms.

Emerging research suggests that exposure to neonics in the womb or early life could be linked with developmental defects, autism, heart deformations, muscle tremors, memory loss, and endocrine disruption.

Glyphosate has been listed as a probable carcinogen by the World Health Organization and a known carcinogen by the California Office of Human Health Hazard Assessment. It has been linked to high rates of non-Hodgkins lymphoma in farmers and groundskeepers who use the herbicide, leading to more than 100,000 court cases against Bayer (formerly Monsanto) who makes the pesticide.

Glyphosate exposure has also been linked to high rates of kidney disease and shortened pregnancy. Animal studies and bioassays link glyphosate and its formulations to endocrine disruption, DNA damage, decreased sperm function, disruption of the gut microbiome, and fatty liver disease

Other Pesticides of Concern

We can’t just focus on a few problematic pesticides at a time. Without a holistic shift to organic and regenerative farming, farmers will likely replace one harmful pesticide with another, a process known as regrettable substitution. 

These lists provide a more extensive picture of pesticides of concern:

• Friends of the Earth’s list of pesticides of concern for pollinators 
• Pesticide Action Network’s list of Highly Hazardous Pesticides

Policy and Regulation

Despite mounting evidence of harm, these pesticides remain widely used in the United States.

Stronger protections are needed to:

• Restrict or ban pollinator-toxic pesticides
• Improve pesticide safety standards
• Protect endangered species
• Reduce environmental contamination

Some states have taken steps to limit the use of certain neonicotinoids, demonstrating that policy change is possible.

Glyphosate has been banned in Mexico, Germany, France, Austria, Malawi, Oman, Saudi Arabia, Kuwait, United Arab Emirates, Bermuda, Thailand, Vietnam, Bahrain, Qatar, and St Vincent and the Grenadines. It has been restricted in Belgium, France, Denmark, Italy, the Netherlands, Czechia, Brazil, Sri Lanka, and hundreds of other locations around the globe.

Solutions

Reducing reliance on harmful pesticides is essential. Proven solutions include:

• Transitioning to organic and regenerative farming practices
• Eliminating unnecessary pesticide use in landscaping
• Supporting policies that protect pollinators
• Encouraging safer pest management alternatives

By shifting toward ecological agriculture and stronger safeguards, we can protect pollinators, biodiversity, and public health.