Use of human nail as bio-indicators among various biopsy materials (urine, blood and other body fluids) is more attractive in assessing toxic and essential elements. This is in view of the fact that collection of nail samples is non-invasive. In addition, storage, preparations and analysis of the samples is also economical, and not susceptible to contamination. Vulnerable groups including children, pregnant women, elderly or chronically-ill are likely to benefit from this non-invasive procedure as a result of repeated or routine examinations. Use of nail tissue has therefore been proposed...