(Beyond Pesticides, December 20, 2013) The European Food Safety Authority (EFSA) announced on Tuesday that pesticides linked to honey bee deaths worldwide may also damage human nervous systems —in particular the brain, and recommended that the European Commission lower the guidance levels of acceptable exposure until more research is conducted. This new determination heightens the call to ban the use of these toxic chemicals in the U.S., following the lead of the European Union (EU).
EFSA found that two commonly used chemicals “may adversely affect the development of neurons and brain structure associated with functions such as learning and memory” particularly of children. The recommendation focuses on two chemicals —acetamiprid and imidacloprid— in a relatively new class of insecticide called neonicotinoids. Three chemicals in this class were recently placed under a two-year ban in the European Union (EU) for uses on flowering crops known to attract honey bees.
The move stems from a recent review of research on rats which found, “Neonicotinoids may adversely affect human health, especially the developing brain.” Researchers who exposed newborn rats to one of these chemicals —imidacloprid— found they suffered brain shrinkage, fewer nerve signals controlling movement, and weight loss. Another study on rats found that exposure to the other neonicotinoid —acetamiprid— caused delayed responses to startling sounds, weight loss, and reduced survival rates.
In its decision, EFSA recommends that the acute reference dose —the amount ingested over a day that does not demonstrate appreciable health risks— be cut by three quarters for acetamiprid and a quarter for imidacloprid. Additionally, the acceptable daily intake—the amount ingested over a lifetime without appreciable risk—should be cut by two thirds for acetamiprid.
Imidacloprid has been banned in the EU for use on certain flowering crops since December 1, after EFSA determined it, and two other neonicotinoids, pose an unacceptable risk to pollinators. Several studies leading to the ban have demonstrated the impact neonicotinoid pesticides have on the navigation, foraging, learning, and immune health of honeybees.
It is commonly cited that bees are exposed to the poison when dust from pesticide-coated seeds mixed with lubricants, such as talc, escape from mechanical seed planters. But that’s not the only and perhaps most hazardous route of exposure. Neonicotinoids are systemic, meaning that as a coated seed grows into a plant the pesticide becomes incorporated into the plant. When honey bees and other pollinators forage and collect pollen or nectar, or drink from what are termed “guttation” (water) droplets emitted from neonicotinoid-incorporated crops, they are exposed to sublethal doses of the chemical. At this level the pesticides don’t kill bees outright. Instead, they impair bees’ ability to learn, to find their way back to the hive, to collect food, to produce new queens, and to mount an effective immune response.
Unfortunately, despite strides in research demonstrating the effect of neonicotinoid exposure on honey bees, the U.S. Environmental Protection Agency (EPA) has failed to take action. While EPA has made recent labeling changes to try to reflect pollinator concerns, beekeepers widely agree that they do not go far enough in bee protection. Similarly, although beekeepers have voiced their concerns about sublethal exposures, EPA has only taken steps to address acute bee poisonings, which they say are primarily caused by dust plumes from seed coatings. Manufacturers are working to reformulate the seed coating technology to control dust, but EPA has made no move to restrict the use of the chemicals which are conclusively demonstrated to cause bee deaths through sublethal exposure.
In March 2013, Beyond Pesticides. Center for Food Safety, Pesticide Action Network North America, beekeepers, environmental and consumer groups filed a lawsuit in Federal District Court against the EPA for its failure to protect pollinators from dangerous pesticides. The lawsuit seeks to suspend the registrations of insecticides clothianidin and thiamethoxam, which have repeatedly been identified as highly toxic to honey bees. The suit challenges EPA’s oversight of these bee-killing pesticides, as well as the agency’s practice of “conditional registration,” which leave critical health and environmental questions unanswered, and labeling deficiencies.
With the support of over 60 organizations, Beyond Pesticides has also helped launch a coalition-based national advertising campaign to raise awareness of pollinator declines and urge EPA to stop stalling by enacting substantive restrictions on the use of bee-harming pesticides.
To support our efforts to restrict bee-toxic pesticides. visit save-bees.org and sign the petition to EPA Administrator Gina McCarthy. For additional information on the decline of honey bees and other wild pollinators, and a history of our efforts to get EPA to act, visit Beyond Pesticides’ BEE Protective webpage.