Problems of metrological provision of the measurements when monitoring food contamination

Various aspects of radioactive contamination monitoring of environmental objects and food with regard to sample isotope composition changing in time, are considered. In samples of technogenic origin with relatively low activity a notable difference in data, obtained by gamma-spectrometric analysis and beta-radiometry methods is explained by the effect of natural 40K contained in samples. Recommendations concerning gamma-spectrometry method application to such samples are given