Publication
Radioactivity contents in dicalcium phosphate and the potential radiological risk to human populations
Publisher:
Elsevier BV
Date:
30-10-2009
DOI:
10.1016/J.JHAZMAT.2009.05.037
Abstract: Potentially harmful phosphate-based products derived from the wet acid digestion of phosphate rock represent one of the most serious problems facing the phosphate industry. This is particularly true for dicalcium phosphate (DCP), a food additive produced from either sulphuric acid or hydrochloric acid digestion of raw rock material. This study determined the natural occurring radionuclide concentrations of 12 DCP s les and 4 tricalcium phosphate (TCP) s les used for animal and human consumption, respectively. Metal concentrations (Al, Fe, Zn, Cd, Cr, As, Hg, Pb and Mg) were also determined. S les were grouped into three different clusters (A, B, C) based on their radionuclide content. Whereas group A is characterized by high activities of 238U, 234U (approximately 10(3) Bq kg(-1)), 210Pb (2 x 10(3) Bq kg(-1)) and (210)Po ( approximately 800 Bq kg(-1)) group B presents high activities of (238)U, (234)U and (230)Th (approximately 10(3) Bq kg(-1)). Group C was characterized by very low activities of all radionuclides (< 50 Bq kg(-1)). Differences between the two groups of DCP s les for animal consumption (groups A and B) were related to the wet acid digestion method used, with group A s les produced from hydrochloric acid digestion, and group B s les produced using sulphuric acid. Group C includes more purified s les required for human consumption. High radionuclide concentrations in some DCP s les (reaching 2 x 10(3) and 10(3) Bq kg(-1) of 210Pb and 210Po, respectively) may be of concern due to direct or indirect radiological exposure via ingestion. Our experimental results based on 210Pb and 210Po within poultry consumed by humans, suggest that the maximum radiological doses are 11 +/- 2 microSv y(-1). While these results suggest that human health risks are small, additional testing should be conducted.