Variation of the ratio of cesium-137 to strontium-90 in the atmosphere.
D000398:Air Pollution, Radioactive / Q000032:analysis*; D001131:Arkansas; D002587:Cesium Isotopes / Q000032:analysis*; D011868:Radioisotopes / Q000032:analysis*; D013326:Strontium Radioisotopes / Q000032:analysis*
D002587:Cesium Isotopes; D011868:Radioisotopes; D013326:Strontium Radioisotopes