The concepts embodied in the development and implementation of a comprehensive R and D and program planning capability for EHS were examined. Environmental stressors were selected as the basis for planning rather than categorical approaches. For the mix of complex problems encountered by EHS, a system to establish priorities is required. The integrated planning system which was recommended utilizes mathematical models to assess the impacts of technology upon man and his environment and the assignment of priorities based upon quality of life indices. Specific elements of the management-assistance system which was defined include an overview environmental health planning function to provide coordinated and comprehensive planning in the man-centered ecosystem context; an impact assessment capability based upon a hierarchy of mathematical models; a threat identification function to identify and evaluate potential threats to man and the environment through intensification or extension of current use patterns of products and services or through introduction of new stressors; and an environmental health information network to provide a well-organized information base. A hierarchical approach to the development of mathematical models for prediction of the impacts of stressors upon man and the environment was described and specific examples are presented for lead in the environment. (Author)