acta physica slovaca vol. 58 No. 1, 1 – 154 February 2008 NEW ISOTOPE TECHNOLOGIES IN ENVIRONMENTAL PHYSICS P.P. Povinec a, 1 , M. Betti b , A.J.T. Jull c , P. Vojtyla d a Faculty of Mathematics, Physics and Informatics, Comenius University Mlynsk´ a dolina F-1, SK-84248 Bratislava, Slovakia b European Commission, Joint Research Centre, Institute for Transuranium Elements P.O. Box 2340, 76137 Karlsruhe, Germany c NSF Arizona AMS Laboratory and Departments of Physics and Geosciences University of Arizona, Tucson, AZ 85721-0081, USA d European Organization for Nuclear Research (CERN), Geneva, Switzerland Received 17 April 2008, accepted 24 April 2008 As the levels of radionuclides observed at present in the environment are very low, high sensi- tive analytical systems are required for carrying out environmental investigations. We review recent progress which has been done in low-level counting techniques in both radiometrics and mass spectrometry sectors, with emphasis on underground laboratories, Monte Carlo (GEANT) simulation of background of HPGe detectors operating in various configurations, secondary ionisation mass spectrometry, and accelerator mass spectrometry. Applications of radiometrics and mass spectrometry techniques in radioecology and climate change studies are presented and discussed as well. The review should help readers in better orientation on recent developments in the field of low-level counting and spectrometry, and to advice on construction principles of underground laboratories, as well as on criteria how to choose low or high energy mass spectrometers for environmental investigations. PACS: 07.85.Nc, 24.10.Lx, 29.20Ba, 29.30.Ep, 29.40Mc, 29.40.Wk, 82.80.Ms, 92.60.Ry, 98.70.Sa KEYWORDS: Radionuclides; Depleted uranium; HPGe detectors; Liquid scintilla- tion spectrometry; Low-level counting; Underground laboratory; Monte Carlo simulation; GEANT; In situ underwater gamma-spectrometry; Mass spectrometry; Secondary ionisation mass spectrometry; Induc- tively coupled plasma mass spectrometry; Thermal ionisation mass spectrometry; Resonance ionisation mass spectrometry; Accelerator mass spectrometry; Radioecology; Climate change 1 E-mail address: povinec@fmph.uniba.sk; formerly at the International Atomic Energy Agency, Monaco. 1