Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: April 17, 1998
Publication Date: N/A
Technical Abstract: Chemical elements often are measured in hair samples with the hope of obtaining useful clinical, epidemiologic, forensic, nutritional or toxicologic information (Klevay, et al. Am J Clin Nutr 46:233,1987). Analytical methods are sufficiently accurate and precise; medical utility remains largely unproven because of insufficient clinical validation and ignorance of potential variability. The subject of this study used two brands of shampoo low in copper and zinc and collected occiptonuchal hair samples with regularity between February, 1968 and December, 1986. No unusual occupational exposures to chemical elements occurred. Elements in hair were measured by inductively coupled plasma spectroscopy after washing, desication and dissolution (Klevay, Am J Clin Nutr 23:284, 1970). Analytical sensitivity was optimized for manganese. Analysis of hair samples in random order revealed (ug/g, +/- SD,n = 21): Calcium 304 +/-173 Magnesium 47.2+/-34 Potassium 27.4+/-41 Copper 17.7+/-14 Manganese 0.17+/-0.18 Sodium 156 +/-51 Iron 9.88+/-10 Phosphorus 136+/-19 Zinc 170+/-18 Coefficients of variation range from 11 (Zn) to 150% (K). Within person variability decreases the potential usefulness of measurement on a single sample. Neither seasonal effects nor time trends have been found so far. Hair analysis for Ca, Fe, K, Mg, Na, and P probably is based more on analytical ease than on medical utility; other methods of status assessment remain superior. Therapeutic intervention based on hair analysis probably is undesirable without supporting data.