21
Apr
Literature Review Adds to the Growing Evidence that Inert Ingredients Are Toxic to Pollinators
(Beyond Pesticides, April 21, 2022) A literature review published in Royal Society finds that ‘inert’ ingredients’ in pesticide formulations adversely affect the health of bees and other wild pollinators. Inert ingredients, also known as “other” ingredients, and not disclosed by name on pesticide product labels, facilitate the action of active ingredients targeting a specific pest. Although both ingredients have chemical and biological activity, most studies on agricultural chemical toxicity focus on the active ingredient, assuming that inert ingredients are “nontoxic.” The U.S. Environmental Protection Agency (EPA), in regulating pesticides, assesses the toxicity of individual active ingredients on bees through various testing methods. However, there are no requirements for EPA to test inert ingredients to the same degree, despite evidence demonstrating these chemicals harm pollinators. Moreover, EPA does not require pesticide manufacturers to disclose the inert ingredients used in any product as the information is confidential.
Both wild and commercial bees and other pollinators encounter multiple stressors, including pesticides, parasites, and poor nutrition, that act together to increase the risk of bee mortality. Therefore, reviews like these highlight the need for pesticide testing to consider the effects of all product ingredients, regardless of perceived toxicity. The researchers caution, “We argue that ‘inert’ ingredients have distinct, and poorly understood, ecological persistency profiles and toxicities, making research into their individual effects necessary. We highlight the lack of mitigation in place to protect bees from ‘inert’ ingredients and argue that research efforts should be redistributed to address the knowledge gap identified here. If so-called ‘inert’ ingredients are, in fact, detrimental to bee health, their potential role in widespread bee declines needs urgent assessment.”
In conducting a systemic literature review of studies regarding the effects of inert ingredients on bee health, researchers find no empirical evidence that inert ingredients are nontoxic, despite that often being the assumption. There are only 19 studies that test the effects of inert ingredients on bee health. The results demonstrate that multiple exposure routes act in conjunction and synergistically with other stressors (e.g., disease, climate, habitat destruction, etc.) to cause bee mortality with colony-level consequences.
The United Nations states that 75 percent of the 115 top global food crops depend on insect pollination, with one-third of all U.S. crops depending on pollinators, according to the U.S. Department of Agriculture (USDA). However, research finds that many insect populations are declining, including managed and wild pollinators, mainly due to habitat fragmentation, climate change, and extensive pesticide use. There are various classes of bee-toxic pesticides, such as neonicotinoids, sulfoxaflor, pyrethroids, fipronil, and organophosphates. Research shows that residues from neonicotinoids (including seed treatments) and sulfoxaflor accumulate and translocate to pollen and nectar of treated plants, increasing the potential risk and indiscriminate to pollinators. Both pyrethroids and fipronil impair bee learning, development, and behavioral function, reducing survivability and colony fitness. However, inert ingredients in these products cause similar or more severe impacts on bee populations, such as disruption in bee learning behavior through exposure to low doses of surfactants. With the global reliance on pollinator-dependent crops increasing over the past decades, a lack of pollinators threatens food security and stability for current and future generations.
The study finds only 19 studies investigate the effects that inert ingredients have on pollinator health, despite the fact that inerts typically make up most of the ingredients in pesticide formulations, up to 99 percent in some cases. Although manufacturers claim inert ingredients, including surfactants, emulsifiers, and other co-formulants, do not harm target pests like active ingredients, inerts can be even more toxic than active ingredients as these chemicals magnify the effects of active ingredients, sometimes as much as 1,000-fold. Moreover, inert ingredient exposure can occur through many routes, impacting both target and non-target species. One of the most hazardous ingredients in the commonly used herbicide Roundup, POEA, is a surfactant classified as an inert and therefore unlisted on the label. However, researchers find that POEA can kill human cells, particularly embryonic, placental, and umbilical cord cells. Therefore, it is essential for agencies to require manufacturers to disclose inert ingredients to limit adverse health effects in the ecosystem, especially among non-target species.
This is not the first research to cite inert ingredients as dangerous to pollinators. Inert ingredients in pesticide mixtures, like N-methyl-2-pyrrolidone and Slygard 309 (surfactant), increase baby bee mortality and honey bee susceptibility to deadly viruses. The latest concerning news on inert ingredients revolves around widespread findings that PFAS chemicals contaminate pesticide products. A 2017 study detected PFAS chemicals in bee hives, with another study indicating PFOS (a certain type of PFAS chemical) can increase honey bee mortality and halt brood development. Although evidence suggests inert ingredients are the primary culprit of pollinator decline, scientists maintain agency assessments should not disregard the impacts that active ingredients have on pollinator health. A 2018 study found that technical grade (pure) glyphosate disrupts honey bee microbiota, with sublethal effects on honey bee navigation and foraging success. Moreover, science accumulated over the last decade and a half demonstrates that neonicotinoids, and the multitude of pollinator-toxic pesticides, are critical factors in the cause of pollinator declines. Federal law, under the Federal Insecticide, Fungicide, and Rodenticide Act, protects as proprietary information the disclosure of inert ingredients specific to pesticide products unless the EPA Administrator determines there is a public health issue.
The study concludes, “Evidence of ‘inert’ ingredients having the potential to cause mortality in bees dates back to the 1970s, yet in the EU and U.S., there is still no regulatorily mandated toxicity testing of ‘inert’ ingredients. This means that the only currently available research stream is academic testing, which accounts for the small number of studies to date. As a result, this represents a large gap in our understanding of pesticide ecotoxicology. The research collated here demonstrates that ‘inert’ ingredients are not inert and can pose significant risks to bee health. We call on researchers to devote more attention to ‘inert’ ingredients and regulators to require testing of ‘inert’ ingredients to ensure their safety to bees.”
As has been widely reported, pollinators (such as bees, monarch butterflies, and bats) are a bellwether for environmental stress as individuals and as colonies. Pesticides intensify pollinators’ vulnerability to health risks (such as pathogens and parasites) with pesticide-contaminated conditions limiting colony productivity, growth, and survival. However, ending toxic pesticide use can alleviate the harmful impacts of these chemicals on species and ecosystem health. Beyond Pesticides captured the bigger picture in its introduction to its 2017 annual Pesticide Forum, Healthy Hives, Healthy Lives, Healthy Land: “Complex biological communities support life.”
Learn more about the science and resources behind pesticides’ impact on pollinators, including bee pollinator decline, and take action against the use of pesticides. To find out more about what you can do to protect bees and other pollinators, check out information on the BEE Protective Campaign, pollinator-friendly landscapes, pollinator-friendly seeds, pesticide-free zones, bee-friendly habitats, and what you, or your state representative, can do to protect our pollinators. For more information on the insect apocalypse, see the Beyond Pesticides article in our Pesticides and You newsletter, Tracking Biodiversity: Study Cites Insect Extinction and Ecological Collapse.
Furthermore, buying, growing, and supporting organic agriculture can help eliminate the extensive use of pesticides in the environment. Organic land management eliminates the need for toxic agricultural pesticides. For more information on how organic is the right choice for consumers and the farmworkers who grow our food, see the Beyond Pesticides webpage, Health Benefits of Organic Agriculture.
With Earth Day tomorrow, get ready to grow your spring garden the organic way by Springing Into Action, pledge to eliminate toxic pesticide use by signing the Ladybug Love Pledge and follow up with other actions that will make a difference.
Source: Royal Society
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
