Neonicotinoids are a relatively new class of insecticide, but have quickly become the most widely used class of agricultural insecticides in the world. Historically, neonicotinoid insecticides have been viewed as ideal replacements for more toxic compounds, like organophosphates, due in part to their perceived limited potential to impact the environment and human health. The use of neonicotinoids has become particularly intense in Iowa and neighboring states as a corn and soybean seed treatment. Few studies have been conducted to characterize human exposure to neonicotinoids or the insecticides potential health risks.

Based on the increased intensity and geographic use of the more commonly used neonicotinoid insecticides in the U.S., pesticide applicators in Iowa have high potential for exposure from using corn and soybean seeds coated with neonicotinoids (see example of imidacloprid use Figure 1). Although the Agricultural Health Study (AHS) has been collecting information on pesticide usage and estimating exposures since 1993, AHS-based studies assessing neonicotinoid exposure and potential adverse health outcomes have not been performed. In fact, there have been no analytic epidemiologic studies performed nationwide that have assessed neonicotinoid-related adverse health outcomes using individual level exposure data.

The long-term goal of the proposed research is to assess the health risk posed by chronic exposure to neonicotinoid insecticides and their metabolites. In addition, the study will assess exposure risks of other environmental contaminants such as nitrate, arsenic, lead, broad spectrum pesticides and their degradates, perfluorinated alkylated substances, antibiotics and pharmaceuticals, and selected microbes.