Measurement of natural and artificial radioactivity in powdered milk consumed in Jordan and estimates of the corresponding annual effective dose

The activity concentrations of K-40, Ra-226, Ra-228 and Cs-137 were measured for 14 brands of the powdered milk consumed in Jordan, which are imported from various regions around the world. The activity concentrations of K-40 were found not to vary greatly from one brand to the other with an average of 348 +/- 26 Bq kg(-1). However, the activity concentrations of Cs-137 revealed a geographical distribution being: (i) undetected in any of the samples from Argentina, (ii) uniformly distributed in samples from Europe with an average of 0.43 +/- 0.05 Bq kg(-1), and (iii) widely varying in samples from New Zealand (from being not detected (ND) to 1.55 Bq kg(-1)). Ra-226 and Ra-228 were measured above the detection limits in five brands only and displayed relatively low activity concentrations of 0.50-2.14 and 0.78-1.28 Bq kg(-1) for Ra-226 and Ra-228, respectively. The total average annual effective doses due to intake of K-40, Ra-226, Ra-228 and Cs-137 from the ingestion of the powdered milk for infants, children and adults were estimated to be (in mu Sv): 332, 138 and 43, respectively. These results indicate no significant radiation dose to the public.