A simplified procedure for the assay of picocurie concentrations of radium-226 and its application to a study of the natural radioactivity in surface waters in Scotland
A complete and simplified emanation system for the measurement of picocurie concentrations of radium-226 is described. A scintillation detector, fabricated from Perspex, and standard commercial electronics are used. Efficiencies of 55 per cent, were obtained with backgrounds of about 1 count per minute for several detectors. Studies have been conducted of the natural radioactivity in Loch Lomond and surrounding streams. The Loch surface water has an average radium-226 concentration of 0·04 pCi l–1 and the uranium concentration, as determined by delayed neutron technique, is 0·13 µg l–1. These results suggest that the amounts of radium-226 in the oceans are independent of the influx from streams, and that drinking water in this region of Scotland does not constitute a significant intake of radium-226 by humans.