At the request of the U.S. Army Surgeon General, the Institute of Medicine has convened an expert committee to evaluate these guidelines from scientific and ethical perspectives. This report, Part I of this committee's efforts, focuses on the scientific merit of the current NATO guidance by responding to the three-part charge:

1. Do the presently proposed NATO guidelines (dose limits, documentation, and control measures) follow generally accepted U.S. national limits and recommended guidelines for radiation protection of occupational and emergency workers?
2. Are these NATO guidelines reasonable from a scientific viewpoint?
3. How could the guidelines be improved?

The committee will report next year, in Part II, its follow-on deliberations on other critical factors, including ethics, risk perception, record keeping, training, communication, and decision making, with additional scientific information as necessary. The Army requested that the committee complete its technical review of the ACE Directive as quickly as possible, concentrating on the broader issues of ethics and law in the second year of the study. The technical recommendations we now present do not yet include these extremely important considerations.

Not surprisingly, however, we found each technical point to be associated with numerous considerations that involve societal, organizational, and personal values. The committee will spend its next year of research and deliberation in providing the Army Surgeon General with cogent and practical guidance that includes and reflects this broader philosophical context. Because of this, the current review must be considered a work in progress; it will not be complete until the final report adds the broader perspective.

In answering its charge, the committee reviews the basic principles of radiation physics and radiobiology and presents an overview of current practices in radiation protection in the civilian sector and in the Army. From this basis the committee comments on the technical aspects of the NATO guidance and makes several recommendations.

This report is about radiation protection, the aims of which are (a) to prevent the occurrence of acute health effects (e.g., cataracts in the eyes and radiation sickness) and (b) to ensure that all reasonable steps are taken to reduce the induction of potential long-term effects (e.g., cancer) to a level that is acceptable to society (ICRP, 1991a).¹ To achieve these aims, radiation doses to individuals and populations must be measured and controlled. These doses (related to the amount of radiation energy deposited in tissue per unit of mass) typically are