THE MEASUREMENT OF RADIATION EXPOSURE OF ASTRONAUTS BY RADIOCHEMICAL TECHNIQUES. DETERMINATION OF THE RADIONUCLIDE CONTENT OF FECES AND URINE FROM ASTRONAUTS ENGAGED IN SPACE FLIGHT. Quarterly Research Report to the NASA Manned Spacecraft Center, April 8--June 30, 1969.

Cosmic radiation doses to the crews of the Apollo 14, 15 and 16 missions of 142 + 80, 340 + 80, and 210 + 130 mR respectively are calculated from the specific activities of 22 Naand 24 Nain the postflight urine specimens of the astronauts. The specific activity of 59 Feis higher in the urine than in the feces of the Apollo 14 and 15 astronauts, and a possible explanation is given. The concentrations of 40 K,, 42K, 51 Cr, 60 Co, and 137 Csin the urine are also reported for these astronauts. The radiation doses received by pilots and navigators flying high, altitude missions during the solar flare of March 27-30, 1972 are calculated from the specific activity of 24 Nain their urine. These values are compared with the expected radiation dose calculated from the known shape and intensity of the proton spectrum and demonstrate the magnitude of atmospheric shielding. The concentrations of Na, K, Rb, Cs, Fe, Co, Ag, Zn, Hg, As, Sb , Se , and Br have been measured in the urine specimens from the ' Apollo 14 and 15 astronauts by neutron activation analysis. The mercury and arsenic levels are much higher than expected. No significant differences were observed between preand postflight samples. ^ ._.::..,. ....,. ,, _,.n; __ ., .. ,,.., .: o., .., ..: ^.^,. vR3 . ..^»*r,ew. ,^1'et¢rra w*Ex'.^^?F. 3"b-R+1 t^' w9r^!:a"y`ff^""' ;^7y„̂ ^cr3 rhl. ^!v'Yi4'^:'*#Y:^,.^ K .. u .. ,^.;+r^m.^.+w,..,,,^,, ,. .r. .,... a _ ,v w , ... ., -.'L'T..w.'t, u!» w aka .+izF >'•'^RFitr x.^ z.:s_.4 C'a:a. YHJ!'rhM.).K".7w X:, :: xk :`. r i.w Fal Y" , 1. 6'IFAIR. .'OA a, .. .. X Y..^s u!r-aiMtt^a^s ..:^.s"« ^k a^ .c:40.'1"-Y 'ifA..., as y ..., . > ^ ,... .. ... :.^. .... s.,..o . ... K "T ^1i'^4"icM. , .ra^:.;Y,