Book excerpt: Scientists agree that exposure to toxic agents in the environment can cause neurological and psychiatric illnesses ranging from headaches and depression to syndromes resembling parkinsonism. It can even result in death at high exposure levels. The emergence of subclinical neurotoxicity-the concept that long-term impairments can escape clinical detection-makes the need for risk assessment even more critical. This volume paves the way toward definitive solutions, presenting the current consensus on risk assessment and environmental toxicants and offering specific recommendations. The book covers: The biologic basis of neurotoxicity. Progress in the application of biologic markers. Reviews of a wide range of in vitro and in vivo testing techniques. The use of surveillance and epidemiology to identify neurotoxic hazards that escape premarket screening. Research needs. This volume will be an important resource for policymakers, health specialists, researchers, and students.