Owing to the long-lasting environmental issues related to the persistent organochlorine pesticides described earlier, nearly all pesticides used today are nonpersistent. While they are designed to break down in a matter of hours or days, it has been shown that many nonpersistent pesticides can remain for years after application in homes and other indoor environments where they are protected from moisture, sunlight, and other degradation mechanisms. Exposure is multimedia, multipathway, and multiroute and can depend on the chemical, scenario, and population. Pesticides are known neurotoxins, especially in high-dose situations. Many commonly used pesticides are also known or suspected EDCs, although studies of potential endocrine effects have greatly lagged behind research focused on their designed mode of action (eg, cholinesterase inhibition). Among all the types of pesticides (insecticides, herbicides, fungicides, rodenticides, etc), most research in humans has been conducted for insecticides. The most common classes of insecticides are organophosphates, carbamates, and pyrethroids. Of these, the organophosphates, some of which have been banned or restricted for residential but not agricultural use in the United States, have been studied the most.