Abstract: There are currently a number of initiatives aimed at considering and redefining the role of environmental health. These include an effort under the auspices of the Institute of Medicine Roundtable on Environmental Health and another under the auspices of the American Schools of Public Health. Both will result in conferences to be held in the same month of the New York Academy of Sciences (NYAS) conference on “The Role of Neural Plasticity in Chemical Intolerance”, for which this paper is being prepared. This questioning of our definition and of our approach to the field of environmental health is an instructive background on which to consider the issue of environmental risks and public health—the topic given to me by the organizers of the NYAS conference. My approach will be to touch on those issues related to the nervous system and to unexplained symptoms in keeping with the subject of the conference, as well as to discuss some of the broader issues surrounding environmental health.