that the posture in a trench could not have been altered significantly during this exposure. The fission-product gamma dose, however, was delivered over a period of many seconds (5). Therefore, the possibility of individual reorien- tation (e.g., standing up to observe the rising fireball) in the trench was considered (1; 12). The calculation of the dose from residual radiation followed from the characterized radiation environment and personnel activities. Because radiation intensities were calculated for a field (i.e., in two spatial dimensions) and in time, the radiation intensity was determinable for each increment of personnel activity regardless of direction or at what time (1; 3). The dose from exposure to a radiation field was obtained by summing the contribution (product of intensity and time) to dose at each step. The dose calculated from the radiation field did not reflect the shielding of the film badge afforded by the human body. This shielding was determined for appropriate body positions by the solution of radiation transport equations as applied to a radiation field (3). Conversion factors were used to arrive at a calculated film badge dose, which not only facilitated comparison with actual film badge date, but also served as a substitute for any unavailable film badge reading. The calculation of the dose from inhaled or ingested radioactivity primarily involved the determination of what radioisotopes entered the body in what quantity. Published conversion factors (13; 14) were then applied to these data to arrive at the radiation dose and future dose commitments to selected internal organs, such as bone marrow, lungs, and thyroid. Inhalation or ingestion of radioactive material was calculated from the radioactive environment and the processes of making these materials inhalable or ingestible. Activities and processes that caused material to become airborne (such as wind, traffic, or decontamination) were used with empirical data (15; 16) on particle lofting to determine airborne concentrations under specific circumStances. Volumetric breathing rates and durations of exposure were used to calculate the total material intake. Data on time-dependent weapon debris isotopic composition, and the above-mentioned conversion factors, were used to calculate the dose commitment to the body and to specific body organs (4; 17). N. nO a 172