Trace elements in human hair

Several studies have shown significant differences in the composition of oily versus dry hair. Perhaps the most comprehensive study in this regard was by Koch et al. [152], who examined hair surface lipid from 20 dry- and oily-haired subjects, three days after shampooing, and found the following correlations with increasing hair oiliness  

An increasing ratio of unsaturated to saturated fatty acids. 

An increasing amount of monoglycerides, and A decreasing percentage of cholesterol esters. 

The quantity of total lipid was not found by Koch to correlate with hair oiliness. However, this is not surprising (in a several-day study) because the quantity of lipid on hair tends to level after a few days from the last shampooing owing to removal of excess lipid by rubbing against objects such as combs or brushes and even pillows and hats. 

Koch et al. [152] explained oily versus dry hair by the rheological characteristics of the resultant scalp lipid. For example, increasing the ratio of unsaturated to saturated fatty acids should decrease the melting point of the sebum, making it more fluid or more oily. Monoglycerides are surface-active and, therefore, should enhance the distribution of sebum over the hair [152]. Factors such as fiber cross-sectional area or hair curliness were kept constant in Koch s experiments and thus were not considered however, one would expect the degree of oiliness to affect straight, fine hair the most and to have the least cosmetic effect on curly coarse hair [153]. 

Some authors have stated that human hair can be employed as an index for an excess, or a deficiency, of specific nutrients in the diet or as an index of absorption of contaminants from the environment [39]. Analysis of hair is considered to give an indication of the integrated dose of elements ingested by a person over some months. In addition, it is easier to collect hair than blood or urine. Therefore, analysis of human hair is performed by a number of organisations to monitor the level of exposure to heavy metals of a population or an individual [40]. However, this monitoring is often hampered by an insufficient reliability of the measurements. The BCR has thus decided to provide laboratories with a mean of checking their analytical performance by 

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DiPietro ES, Phillips DL, Paschal DC, et al. 1989. Determination of trace elements in human hair Reference intervals for 28 elements in nonoccupationally exposed adults in the US and effects of hair treatments. Biol Trace Elem Res 22 83-100. 

Takagi Y, Matsuda S, Imai S, et al. 1986. Trace elements in human hair An international comparison. Bull Environ Contam Toxicol 36 793-800. 

Sky-Peck, H. H., Distribution of trace elements in human hair, Clin. Physiol. Biochem., 8, 70, 1990. Petering, H. G., Yeager, D. W., and Witherup, S. O., Trace metal content of hair. Arch. Environ. Health,... 

Shizhong, C. Lu Dengh, Hu Zhixong and Wang Zhan (2005) The use of electrothermal vaporisation with ICP-OES for the determination of trace elements in human hair using the slurry sample technique and PTF as a modifier, International Journal of Environmental Analytical Chemistry, 85(7), pp493-501. 

SUMMARY OF TECHNIQUES OF FINAL DETERMINATION USED IN THE CERTIFICATION OF TRACE ELEMENTS IN HUMAN HAIR CRM 397... 

V. Valkovic, Trace Elements in Human Hair, Garland STPM Press, New York and London, 1977. 

D. J. Eatough, J. J. Christensen, R. M. Izatt and C. Hartley, Level of Selected Trace Elements in Human Hair, First Human Hair Symposium, Atlanta, 1973. 

Ryabukhin, Yu.S. (1980) Nuclear-based methods for the analysis of trace elements in human hair. J. Radioanal. Chem., 60,7-30. 

Harrison WW, Yurachek JP, Benson CA. 1969. The determination of trace elements in human hair by atomic absorption spectroscopy. Clin Chim Acta 23 83-91. 

The detection of toxic trace elements in human hair has a longer tradition than their detection in human blood and urine. The first publications appeared at the turn of the century and dealt with the problems of detecting arsenic in human hair after intoxication [1] and the Hg content of hair in syphilis dierapy [2]. 

The qualitative and quantitative composition of the trace elements in human hair is nothing more or less than the analytical reflection of an individual life. It mirrors eating habits, working milieu, environment, and specific habits, and thus acquires very individual characteristics that appear in the hair in chronological order [13,14]. 

Valkovic V (1977) Trace Elements in human hair (Garland STPM Press, NY)... 

P. Bermejo-Barrera, O. Muniz-Naveiro, A. Moreda-Pineiro and A. Bermejo-Barrera, Experimental designs in the optimisation of ultrasonic bath-acid-leaching procedures for the determination of trace elements in human hair samples by atomic absorption spectrometry. Forensic Sci. Internat., 2000, 107(1-3), 105 120. 

Harrison, W.W., Yurachek, J.P. and Benson, C.A. (1969). The determination of trace elements in human hair by atomic absorption spectroscopy. Clin. Chim. Acta, 23, 83-91 Harvey, P.G., Hamlin, M.W., Kumar, R. and Delves, H.T. (1984). Blood lead, behaviour and intelligence test performance in preschool children. Sci. Total Environ., 40, 45-60 Hunter, ]., Urbanowicz, M.A., Yule, W. and Lansdown, R. (1985). Automated testing of reaction time and its association with lead in children. Int. Arch. Occup. Environ. Health, 57, 27-34... 

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