Report on the workshop entitled: "Modeling chemically induced leukemia--implications for benzene risk assessment".

Benzene is a well established bone marrow toxin and human leukemogen. However, the health risk posed by exposure to benzene is a matter of some debate. A workshop organized by the University of California at Berkeley entitled “Modeling Chemically induced Leukemia-Implications for Benzene Risk Assessment” was held in Yountville, California on 11-13 February 1996 to discuss the molecular mechanisms of benzene toxicity and possibilities for modeling leukemogenesis. This workshop brought leading scientists in the fields of hematopoiesis, leukemia biology and benzene toxicology together with experts in mathematical modeling with the aim of building by consensus the foundations for a biologically based model that describes leukemogenesis and can be applied to risk assessment. This report summarizes key points of consensus and dissent on the above issues, and participants recommendations about the feasibility of biologically based modeling applied to benzene. The format of the workshop emphasized discussion and consensus-building over formal presentations. For each topic area (benzene toxicology, leukemia biology and cancer modeling) there was an overview seminar followed by an extended discussion session including all