694 TRANSURANIC ELEMENTS IN THE ENVIRONMENT 



TABLE 1 Concentration of Fallout Plutonium in Man 



♦Data from Mclnroy et al. (1977). 

 fData from Bennett (1976). 



^Estimated on the assumption that 0.05% of the total body 

 burden is present in 10 g of ovaries. 



airborne plutonium concentrations in the New York area and on the assumption that all 

 intake by the human is via inhalation according to the ICRP lung model and ICRP 

 assumptions of tissue distribution and retention (International Commission on Radiologi- 

 cal Protection, 1972). The autopsies, on material collected from many states, were 

 performed over a period extending from 1959 to 1976; the estimates are calculated for 

 New York cumulative exposure to 1964 and 1974. Considering the uncertainties of time 

 and place, the agreement between measured and computed organ burdens is quite 

 reasonable for bone, liver, and lung, the organs of principal hazard concern as deduced 

 from animal toxicity studies. Kidney and gonads also show excellent agreement. This 

 agreement lends confidence to the ICRP assumptions regarding deposition and subse- 

 quent redistribution. The lower than predicted lymph node measurements may, at least 

 partially, reflect the considerable difficulties of sampling pulmonary lymph nodes. 



Transuranic distribution data in man are also available from autopsies on occupation- 

 ally exposed persons (Mclnroy, 1976; Norwood and Newton, 1976) and on intentionally 

 injected patients considered to be suffering from terminal illness (Durbin, 1972; Rowland 

 and Durbin, 1976). In these cases tissue levels are much higher, and a larger number of 

 organs can be analyzed with higher precision. These autopsy data are generally in accord 

 with the more extensive animal data and with the ICRP assumption that 45% of a 

 transuranic reaching the blood will deposit in bone and 45% in liver (International 

 Commission on Radiological Protection, 1972). 



Of particular interest are recent human data relating to the distribution of plutonium 

 within organs. Limited data from sectioned lungs of occupationally exposed persons 

 suggest that initial distribution of inhaled plutonium is relatively uniform (Mclnroy et al., 

 1976) but that, at long time periods following exposure, plutonium concentration is 

 higher in the periphery of the lung (Mclnroy et al., 1976; Nelson et al., 1972). The 

 distribution of plutonium among different bones (Larsen, Toohey, and Ilcewicz, 1976) 

 and the microscopic distribution within bone (Schlenker, Oilman, and Cummins, 1976) 

 have been studied in autopsy material from a patient who died 17 months after 

 plutonium injection. This patient was suffering from Cushing's syndrome, and bone 

 metaboUsm was not normal; nevertheless, the general distribution pattern was encourag- 

 ingly similar to that which would have been predicted from animal studies. 



