neeteetRyNe cafe = 2 ' INTRODUCTION poald ‘ ! as + === SY ~ In this bulletin are presented all strontium-90 measurement data obtained by the University of Chicago Sunshine Project group to date. Results for samples assayed by the Nuclear Science and Engineering Corporation, Pittsburgh, Pennsylvania, under subcontract, are also included and are designated by the letter "P" following the CL number (i.e., CL xxx-P)« The data for all biological samples are presented in units of 1/1000 of the tolerance dose of strontium-90 for an average man of 1000 grams total body con- tent of calcium, Thus, the "Sunshine Unit" 4s 1/1000 microcuries of strontium-90 per 1000 grams calcium or 2.2 disintegrations per minute of strontium-90 per S gram of calcium | Results for water samples ‘are reported in disintegrations per minute of strontium-90 per unit volum, Air concentration data are given in disintegra~_ tions per minute per 106 cubic feet of air. A summary of results obtained on check samples measured by each of several laboratories participating in the Sunshine Program is included, —_— ...-; - & description of theChicagoSunshine mthod, which hasalsobeenadopted by the Nuclear Science and Engineering Corporation, will be presented in a i ~ 1 ult ERE, pt separate report, DOE ARCHIVES, rrere 194