Approximately one-third of all deaths in the western world are due to cancer, and epidemiological studies have established that environmental factors play a major role in the disease. Research on humans has so far been concentrated on statistical studies that try to link incidences of cancers to types of exposure, but this approach is only useful on a gross scale, and the results are necessarily very long in coming. Sensitive procedures are needed to assess the risks
of low-level carcinogen exposure, and to determine the relative dangers of exposure to different substances. Researchers are applying the powerful tools of molecular biology to study DNA damaged by carcinogens to understand the significance of this damage at the level of the individual and its
implications for risk assessment.

A meeting on this subject took place in July 1989 where leading researchers presented and compared the strengths and weaknesses of various research methods, and this volume is a record of those presentations.