Studies on some trace and minor elements in blood. A survey of the Kalpakkam (India) population. Part I: Standardization of analytical methods using ICP-MS and AAS.

Blood is one of the widely used specimens for biological trace element research because of its biological significance and ease of sampling. We have conducted a study of the blood of the Kalpakkam township population for trace and minor elements. For this purpose, analytical methods have been developed and standardized in our laboratory for the elemental analysis of blood plasma and red cells. Inductively coupled plasma-mass spectrometry (ICP-MS), a relatively new technique, has been applied for the analysis of trace elements. Details regarding spectral interference and matrix interference encountered in the analysis of blood and the methods of correcting them have been discussed. Flame atomic absorption spectrometry (AAS)/atomic emission spectrometry (AES) has been applied for the determination of minor elements. Precision and accuracy of these methods have also been discussed.

Studies on some trace and minor elements in blood. A survey of the Kalpakkam (India) population. Part III: Studies on dietary intake and its correlation to blood levels.

In our studies on elemental levels in blood of the Kalpakkam population, it was found that the reference values for many elements were normal, but some deficiency with respect to Se was noticed. As a followup study, the dietary ingredients of the local population were analyzed for trace and minor elements to assess the dietary intake of these elements. Details of the analytical methods developed using the technique of inductively coupled plasma-mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) have been described. The dietary intake of many of these trace and minor elements were found to be quite adequate according to the recommended dietary allowance (RDA) levels prescribed, except for Se and Zn. The dietary intake of Se was found to be in the range 20-50 micrograms/d (as opposed to the RDA of 50-200 micrograms/d), whereas the intake of Zn was found to be in the range 8-10 mg/d (as opposed to the RDA of 15 mg/d). Although the deficiency of Se intake was reflected in the blood, that of Zn was not, probably owing to the high level of homeostasis for this element. Fish and egg were found to be rich sources of Se, followed by cereals and pulses, which were found to be the major sources of Zn.

Studies on some trace and minor elements in blood. A survey of the Kalpakkam (India) population. Part II: Reference values for plasma and red cell, and correlation with coronary risk index.

Since data on the trace element levels in Indian population are lacking, we chose to conduct a survey of the Kalpakkam township population. People in the age group 40-55 were included in this study. Reference values for trace and minor elements of the blood of the Kalpakkam population were arrived at by carrying out the analysis of plasma and red cells of healthy subjects of the Kalpakkam population. Although the "reference values" for many elements were found to be normal and comparable to values available in the literature, slight deficiency with respect to Se was noticed. Subjects with high coronary risk index were also included in the study to assess the possible correlation of elemental and lipid profile. A study of box plots showed that the elements Se, Mg, Na, K, and Fe show significant differences between "high risk" coronary risk index (CRI > 5) and "no risk" (CRI < 4.5). In the plasma, the levels of Mg, Na, and K were found to be less in the high-risk group. In red cells, the amount of Se, Fe, and K were found to be significantly less in the "high-risk" group as compared to the "no-risk" group.