In experimental animal studies, the quantitation of DNA adducts has usually required the use of highly radioactive chemical carcinogens. However, a major breakthrough in detection methods occurred in the early 1980s with the development of the 32P-postlabelling technique. Today, at least 60 laboratories have employed and customized these methods. The conference upon which this volume is based was the first time that the majority of these investigators met to discuss their research. A unique aspect of this meeting was an international effort by 15 different laboratories to quantify carcinogen-DNA adduct level in chemically modified DNA standards and in human tissue samples. The application of 32P-postlabelling together with various biomonitoring techniques as described in this volume marks the beginning of a new approach to human risk assessment based on carcinogen-DNA adducts as molecular biomarkers that are expected to be predictive of clinical disease.