Developmental Neurotoxicity of the Herbicide Atrazine

Atrazine (ATZ) is an agricultural herbicide. Due to persistence and contamination of drinking water sources, ATZ was banned by the European Union, but is still commonly used in the United States and other global regions. The US Environmental Protection Agency has set the maximum contaminant level at 3 μg/L in potable water, though concentrations can greatly exceed this amount depending on the time of year. Alternatively, the World Health Organization drinking water guideline is 100 μg/L. Epidemiological studies report associations with developmental health outcomes and raise concerns about ATZ as a potential carcinogen. Studies in model organisms have identified ATZ as a neurotoxicant. Although there is evidence to support the site of action as the hypothalamus, further studies are needed to determine if this herbicide targets specific pathways within the hypothalamus or if it generally interferes with pathways that the hypothalamus regulates. This chapter focuses on ATZ developmental neurotoxicity with studies reporting disruption of the hypothalamus, neurotransmission, neuronal development, and behavioral processes.