Neonicotinoid Pesticides & Adverse Health Outcomes

Neonicotinoid pesticides are a class of chemicals that act as insecticides by exerting neurotoxic effects via irreversible binding to insect nicotinic acetylcholine receptors. Because nicotinic acetylcholine receptors are also present in the nervous systems of mammals, there is concern that neonicotinoids may impact animals other than their insect targets, including humans. These pesticides have been used increasingly in U.S. agriculture since 2005, when the patents expired on seven neonicotinoids making possible the production of generic products. Almost all agricultural corn and ~ 1/3 of soybeans planted in the U.S. in 2013 were treated with neonicotinoid seed coatings. Aside from agricultural uses, neonicotinoids are also used to control pests such as fleas and lice in livestock and domestic pets. Use of noenicitinoids on food crops, environmental persistence, and possible binding to human nicotinic acetylcholine receptors raise concerns for potential adverse human health impacts with chronic low-level exposures.

NTP conducted a scoping review to identify the extent of publicly available evidence on potential human health effects of seven neonicotinoid pesticides (acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid, and thiamethoxam). A limited body of evidence was identified for use in hazard assessment, primarily due to differences between health outcomes assessed across the published studies. This scoping review by design summarizes publicly available scientific literature and does not include any proprietary studies available to EPA, which likely contain relevant toxicological data that would complement these data and allow for more comprehensive health hazard assessment.