Study on transfers of uranium, thorium and decay products from grain, water and soil to chicken meat and egg contents

摘要

Activity concentrations of the uranium and thorium series radionuclides were determined in chicken meat and eggs as well as in soil, water and other dietary intakes of poultry at five sites of the French territory. These data allow the calculation of transfer coefficients which enrich the database given by the technical report series no. 472 of the IAEA. In egg contents, the highest activity concentrations (in mBq kg ~(-1) fresh weight) are for ~(226)Ra, ranging between 136 and 190 and are much lower for uranium (between 0.51 and 1.30 for ~(238)U). In chicken meat, ~(238)U activity concentration is higher than in egg contents and ranges between 1.7 and 9.7. Concerning ~(232)Th, its activity concentration is lower than uranium and ranges between 0.5 and 4.9. Daily ingested activity concentration by the animals was assessed taking into account the activity concentrations measured in the grains, in the soil and in the drinking water. The activity concentration in grains and the daily intakes allow the calculation of concentration ratios and transfer coefficients for chicken meat and egg contents. In chicken meat the transfer coefficients (d kg ~(-1)) range between 0.0018 and 0.0073 for ~(238)U and between 0.0008 and 0.0028 for ~(232)Th. In egg contents they range from 0.00018 to 0.0018 for ~(238)U and are much higher for radium isotopes (0.10-0.23 for ~(226)Ra and 0.07-0.11 for ~(228)Ra).