Daily mineral intakes for Japanese

Recently it became necessary to assess the dietary intake of both stable and radioactive elements for non-radiation workers. But data of mineral intake in the literature are not good enough for this assessment. ICRP Pub. 23 in 'Reference Man' is one of the best references in this field. ICRP Reference Man was selected as the standard for Caucasian by using values reported during early 1970s or before. Moreover it seems not to be suitable for Japanese (Mongolian). In this report, analytical methods of minerals in total diet samples for Japanese were described. Furthermore, daily intakes for Japanese (Reference Japanese Man) and ICRP Reference Man were compared. After collected by a duplicate portion study and a model diet study, diet samples were dry-ashed followed by wet-digestion with a mixture of HNO3 and HClO4. Diet sample solutions thus prepared were analysed by using atomic absorption spectrometry (AAS), inductively-coupled plasma atomic-emission spectrometry (ICP-AES), and inductively-coupled plasma mass spectrometry (ICP-MS). Matrix effects of major elements (Na, K, P, Ca and Mg) in diet samples were compensated by a matrix-matching method. About 20 elements were simultaneously determined by ICP-AES and ICP-MS, more easily than by AAS. Most of dietary mineral intakes, except for Na, Mn, and Sr, for Japanese were lower than those of ICRP Reference Man. But, dietary intakes were found to be different depending on countries, even among European and American countries. New representative data for as many elements as possible are necessary now. (author)