Determination of thorium and other select trace elements in human tissues by neutron activation analysis

Iyengar pointed out the significance of multidisciplinary approaches to biological trace element research and the problems that may be associated with much of the early trace element data (until the early 1970s). Problems identified included the analysis of spurious samples (e.g., hair) based on their availability with no consideration of the biological basis for the investigations and the uncontrolled collection of biological samples by investigators unable to assess the biological integrity of the sample and inadequate quality assurance/quality control. A significant inadequacy is that many trace element analysis studies have been performed on biopsies or samples that may not be representative of the whole organ, or that distribution data have been derived from pooled analyses of organs from many individuals.