"Introduction The rationale of this study was @to develop suitable animal models for benzene-induced hematopoietic toxicity. The study was essentially divided into three sections or phases. Phase I was a comprehensive literature review which served as a basis for the direction of research and which . was summarized in a monograph. Phase II included the toxicity studies of inhaled benzene and was divided into three areas. Area A was concerned with the inhalation protocols and peripheral blood cell monitoring. Area B dealt with the evaluation of hematological responses other than peripheral cell counts. Area C concerned the effects of benzene exposure on proliferating blood"" cell precursors as reflected by changes in bone marrow cytogenetics and colony forming abilities. Phase III dealt with the study of the metabolism of benzene which was investigated through pharmacokinetic techniques."