The U.S. EPA estimates that there currently are as many as 60,000 chemicals used in this country and that as many as 1000-2000 new ones are introduced into commerce each year. Unfortunately, the ability to assess and predict the possible health hazards associated with exposures has not kept pace with the production of new compounds. As a consequence, there is growing concern that many chemicals introduces originally to improve our lives may in fact be producing a range of organ-related toxicities and disease states. A recent publication of the National Research Council (1984), for example, estimated that for most chemicals sufficient toxicity information was not available to conduct an adequate health-hazard assessment. As a result the toxic potential of many chemicals is often not appreciated until large numbers of the population have been exposed to them. Under these conditions incidents such as the Ginger Jack poisoning episode in the United States, and the methylmercury poisoning episodes in Japan and Iraq are poignant reminders of the extent to which the nervous system may be at risk for exposure to environmental chemicals.