Environmental radioactivity - problems in activity measurements

Laboratory methods for the measurement of radioactivity in environmental samples are considered to be well developed and established. After the Chernobyl accident, however, it became evident that not everywhere was one prepared for quick in-situ activity measurements and that many measurement results were questionable. We show the difficulties occurring in activity measurements with simple instruments to be used directly in the environment. In addition, several problems in gamma-ray spectrometry with environmental samples are discussed, problems which - if disregarded - may also lead to erroneous activity values in the case of laboratory measurements. (orig./HP)