A nationwide survey of Australian homes was conducted to determine the average annual dose equivalents to the Australian population from exposure to Rn and gamma radiation. The exposure to Rn was measured using solid-state track detectors (SSTD), while the gamma radiation dose was concurrently determined using thermoluminescent dosimetry. Dosimeters were placed in approximately 3,400 randomly distributed homes (representing about 1 in 1,400 occupied dwellings) for 12 mo. The average Rn concentration in Australian homes measured over a year is 11 Bq m-3. Using appropriate conversion factors, the annual average effective dose equivalents to the Australian population were determined to be 0.5 mSv and 0.9 mSv for Rn and gamma radiation exposure, respectively.

Seven Angus steers were reared under controlled conditions, slaughtered and their carcasses dissected. Muscles, fat, bones, connective tissues and samples of the steers' diet were measured by gamma spectrometry and the concentrations of potassium and caesium-137 determined. Significant variations in the concentration of each element were found both within and between tissues. Average potassium concentration was about four times greater in the muscle tissue than in the remainder of the carcass. Caesium/potassium ratios were similar in both Caesium/potassium ratios were similar in both bone.The main conclusions reached were as follows:(1) The variations of potassium concentrations in muscle may impose limitations on the potassium-40 technique for estimating muscle content of the living animal for scientific purposes, though not necessarily for estimating commercial value.(2) Differences between animals in caesium-137 content of muscle were fairly consistent over the different muscle groups, and bore some relationship to caesium intake. This indicates that it may be possible to utilize caesium content of a representative muscle to monitor caesium-137 fallout in remote regions of Australia, where milk is not produced.