Radioactivity survey data in Japan, No.76, March 1986

This report presents survey data on radioactivity in environmental and dietary materials in Japan. Environmental materials collected include rain and dry fallout (monthly); airborne dust (quarterly); service water (source water and tap water collected semiyearly) and freshwater (yearly, fishing season); soil (yearly); and sea water (yearly) and sea sediments (yearly). Dietary material samples include total diet; rice (yearly, harvesting season); milk [quarterly (February, May, August and November) at producing districts for WHO program, simiyearly (February and August) at producing districts for domestic program, semiyearly (February and August) at consuming districts, and powdered milk collected semiyearly (April and October)]; vegetables [yearly (harvesting season) at producing and consuming districts]; tea (yearly, the first harvesting season); and fish, shellfish and seaweeds (yearly, fishing season). After being collected, these samples are pretreated and prepared to provide solutions for analysis. Strontium-90 and cesium-137 are separated from the solutions. Analysis of calcium is performed by titration with potassium permanganate. Stable strontium and potassium are determined by atomic absorption and flame emission spectrometry, respectively. After the radiochemical separation, the mounted precipitates are counted for activity using low background beta counters normally for 60 to 90 min. (Nogami, K.)