Assessment of radioactivity in Italian baby food.

A set of measurements have been conducted to determine the activity-level of natural and artificial radionuclides in some baby foods commercialized in Italy. The measurements have been carried out using liquid scintillation, gamma, alpha and mass spectrometry. The activity concentrations ranged from 0.005 to 0.238, from 0.0082 to 1.65, from 0.0003 to 0.015 and from <13.6 to 233.3 Bq kg-1 for 210Po, 238U, 232Th and 40K respectively, whereas they are below the detection limit for 137Cs and 226Ra. The annual effective dose due to intake of 210Po, 238U, 232Th and 40K ranged from 280 and 800 µSv y-1 for infant 1 year old. These values lie well within the typical worldwide range of dose due to the ingestion of all natural radiation reported by UNSCEAR and they are below the internationally recommended level. This indicates that the baby food available in Italy would not pose any significant radiological impact to infant.

EURADOS intercomparison on emergency radiobioassay.

Nine laboratories participated in an intercomparison exercise organised by the European Radiation Dosimetry Group (EURADOS) for emergency radiobioassay involving four high-risk radionuclides ((239)Pu, (241)Am, (90)Sr and (226)Ra). Diverse methods of analysis were used by the participating laboratories for the in vitro determination of each of the four radionuclides in urine samples. Almost all the methods used are sensitive enough to meet the requirements for emergency radiobioassay derived for this project in reference to the Clinical Decision Guide introduced by the NCRP. Results from most of the methods meet the requirements of ISO 28218 on accuracy in terms of relative bias and relative precision. However, some technical gaps have been identified. For example, some laboratories do not have the ability to assay samples containing (226)Ra, and sample turnaround time would be expected to be much shorter than that reported by many laboratories, as timely results for internal contamination and early decisions on medical intervention are highly desired. Participating laboratories are expected to learn from each other on the methods used to improve the interoperability among these laboratories.

Monte Carlo modelling of a voxel head phantom for in vivo measurement of bone-seeker nuclides.

Whole-body counters (WBCs) are used for the assessment of the internal contamination of actinides in the human body. WBCs require adequate calibration procedures that rely on the use of suitable calibration phantoms. A previous study carried out at the ENEA-Radiation Protection Institute was aimed at designing a head calibration phantom in which a heterogeneous distribution of 241Am point sources could satisfactorily approximate an assumed homogeneous contamination throughout the head bones. Suitable correction factors for the WBC detection efficiencies were evaluated with Monte Carlo. The present paper summarises the main aspects and implications of an advanced modelling technique based on a VOXEL approach. The methodology could be extended to other bone-seeker radionuclides.