ABSTRACT
This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book reviews the current state of science as it pertains to the scientific basis, current state of development, validation, and use of biological markers in environmental research. It describes different types of biomarkers that offer promise for environmental monitoring. The biomarkers are arranged in categories defined by the nature of the toxic endpoint being probed. The book proposes a research plan for focusing and coordinating resources necessary to develop and implement a biomarker-based environmental monitoring program. Exposure is difficult to assess because of the wide diversity of potential routes of exposure, the large differences in the biological availability of contaminants associated with the different environmental media, and individual and species-specific differences in the pharmacodynamic disposition of the toxicants. Responses measured at lower levels of biological organization, such as DNA damage or enzyme activity, often provide sensitive and specific responses to particular toxicants.
