Hair analysis is the chemical analysis of a hair sample. Hair may be considered for retrospective purposes when blood and urine are no longer expected to contain a particular contaminant, typically a year or less.^[1] Its most widely accepted use is in the fields of forensic toxicology and, increasingly, environmental toxicology.^[2][3] Several alternative medicine fields also use various hair analyses for environmental toxicology but these uses are controversial, evolving and not standardized.

Contents 1 Use in forensic toxicology 2 Hair Alcohol Testing 3 Literature 4 Use in environmental toxicology 4.1 Use in detection of long term elemental effects 4.2 Use in occupational, environmental and alternative medicine 5 References 6 Bibliography 7 External links

[edit] Use in forensic toxicology

Hair analysis can refer to the forensic technique of assessing a number of different characteristics of hairs in order to determine whether they have a common source; for example, comparing hairs found at the scene of the crime with hair samples taken from a suspect.

Hair analysis is also used for the detection of many therapeutic drugs and recreational drugs, including cocaine, heroin, benzodiazepines and amphetamines. ^[4][5] In this context, it has been reliably used to determine compliance with therapeutic drug regimes or to check the accuracy of a witness statement that an illicit drug has not been taken. Hair testing is an increasingly common method of assessment in substance misuse, particularly in legal proceedings, or in any situation where a subject may have decided not to tell the entire truth about his or her substance-using history.

In December 1995 the Society of Hair Testing was founded to promote the research in hair testing technologies in forensic, clinical and occupational sciences, to develop the international proficiency tests, to organize meetings and workshops and to encourage the scientific cooperation and exchanges among members. The Board of the Society of Hair Testing agreed upon the latest version of a Consensus in Sevilla, Spain, in 2004.^{[citation needed]}

[edit] Hair Alcohol Testing

Analysis of hair samples has many advantages as a preliminary screening method for the presence of toxic substances deleterious to health after exposures in air, dust, sediment, soil and water, food and toxins in the environment. The advantages of hair analysis include the non-invasiveness, low cost and the ability to measure a large number of, potentially interacting, toxic and biologically essential elements. Hence, head hair analysis is now increasingly being used as a preliminary test to see whether individuals have absorbed poisons linked to behavioral health problems.^[2]

The use of hair alcohol analysis to establish and verify persistent alcohol abusers within the United Kingdom has steadily increased in recent years. As the hair grows, it absorbs markers called fatty acid ethyl esters (FAEE’s) and ethyl glucuronide (EtG) into its structure, which remain in the hair indefinitely. These markers are only produced when there is alcohol in the bloodstream, such that the more markers there are, the more alcohol you have consumed. The first company to commercialize Hair Alcohol Testing in the UK was Trimega Laboratories. The company has since gone on to commercialize a combined test using EtG and FAEE.

In contrast to other drugs consumed, alcohol is not deposited directly in the hair. For this reason the investigation procedure looks for direct products of ethanol metabolism. The main part of alcohol is oxidized in the human body. This means it is absorbed as water and carbon dioxide. One part of the alcohol reacts with fatty acids to produce esters. The sum of the concentrations of four of these fatty acid ethyl esters (FAEEs: ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) are used as indicators of the alcohol consumption. The amounts found in hair are measured in nanograms (one nanogram equals only one billionth of a gram), however with the benefit of modern technology, it is possible to detect such small amounts. For EtG detection, more sensitive testing can detect picograms (one picogram equals 0.001 nanograms).

However there is one major difference between most drugs and alcohol metabolites (FAEE) in the way in which they enter into the hair: on the one hand like other drugs FAEEs enter into the hair via the ceratinocytes, the cells responsible for hair growth. These cells form the hair in the root and then grow through the skin surface taking any substances with them. On the other hand the sebaceous glands produce FAEEs in the scalp and these migrate together with the sebum along the hair shaft (Auwärter et al., 2001, Pragst et al., 2004). So these glands lubricate not only the part of the hair that is just growing at 0.3 millimeters per day on the skin surface, but also the more mature hair growth, providing it with a protective layer of fat.

It has been technically possible to measure FAEEs since 1993, and the first study reporting the detection of EtG in hair was done by Sachs in 1993. ^[6]

In practice, most hair which is sent for analysis has been cosmetically treated in some way (bleached, permed etc.). It has been proven that FAEEs are (surprisingly) not significantly affected by such treatments (Hartwig et al., 2003a).

FAEE concentrations in hair from other body sites can be interpreted in a similar fashion as scalp hair (Hartwig et al., 2003b).

Extensive studies have enabled researchers to establish reliable reference ranges for FAEEs with respect to the drinking habits of the various groups: Non-Drinkers < 0.4 ng/mg; Excessive Drinkers > 1 ng/mg. Metabolic variation within and across groups of Non-, Moderate-, and Excessive Drinkers limits the utility of current analytical methods. At present, the assessment of FAEEs in an individual's hair sample does not afford the precise quantification of that individual's consumption of alcohol [in units] or blood alcohol level; neither does it yield the precise quantification of the duration for which an individual may have consumed alcohol 'in excess'. Moreover, current methods do not account for different social and legal constructs used by different populations in defining "moderate" vs. "excessive" alcohol consumption - thus making cultural subjectivity another limitation of this approach. Accordingly, to label an individual an "Excessive Drinker" on the basis of their FAEE levels as compared to a test's reference groups' values might be contentious without: (1) a thorough assessment of alcohol metabolism in that specific individual; and (2) consideration for the social and legal environments of that individual.

There are similar reference ranges for Etg from comprehensive studies. Further investigations are in progress to examine the applicability of the method in practice of the detection of alcohol abuse.

[edit] Literature

Pragst F., Balikova M.A.: State of the art in hair analysis for detection of drugs and alcohol abuse; Clinica Chimic Acta 370 2006 17-49.

Auwärter V.: Fettsäureethylester als Marker exzessiven Alkoholkonsums – Analytische Bestimmung im Haar und in Hautoberflächenlipiden mittels Headspace-Festphasenmikroextraktion und Gaschromatographie-Massenspektrometrie. Dissertation Humboldt-Universität Berlin 2006.

Pragst F., Auwärter V., Kiessling B., Dyes C.: Wipe-test and patch-test ror alcohol misuse based on the concentration ratio of fatty acid ethyl esters and squalen CFAEE/CSQ in skin surface lipids. Forensic Sci Int 2004; 143:77-86.

[edit] Use in environmental toxicology

Analysis of hair samples has many advantages as a preliminary screening method for the presence of toxic substances deleterious to health after exposures in air, dust, sediment, soil and water, food and toxins in the environment. The advantages of hair analysis include the non-invasiveness, low cost and the ability to measure a large number of, potentially interacting, toxic and biologically essential elements. Hence, head hair analysis is now increasingly being used as a preliminary test to see whether individuals have absorbed poisons linked to behavioral or health problems.^[2]

[edit] Use in detection of long term elemental effects

There appears to be genuine validity to the use of hair analysis in the measurement of life-long, or long-term heavy metal burden, if not the measurement of general elemental analysis. Several interesting studies including the analysis of Ludwig van Beethoven's hair have been conducted in conjunction with the National Institutes of Health, and Centers for Disease Control and Prevention to name a few.

A 1999 study on hair concentrations of calcium, iron, and zinc in pregnant women and effects of supplementation, it was concluded that "From the analyses, it was clear that hair concentrations of Ca, Fe, and Zn could reflect the effects of supplementation...Finally, it could be concluded that mineral element deficiencies might be convalesced by adequate compensations of mineral element nutrients."^[7]

[edit] Use in occupational, environmental and alternative medicine

Hair analysis has been used in occupational,^[8] environmental and some branches of alternative medicine as a method of investigation to assist screening and/or diagnosis. The hair is sampled, processed and analyzed, studying the levels of mineral and metals in the hair sample. Using the results, as part of a proper examination or test protocol,^[9] practitioners screen for toxic exposure and heavy metal poisoning. Some advocates claim that they can also diagnose mineral deficiencies and that people with autism have unusual hair mineral contents.^[10] These uses are often controversial, and the American Medical Association states, "The AMA opposes chemical analysis of the hair as a determinant of the need for medical therapy and supports informing the American public and appropriate governmental agencies of this unproven practice and its potential for health care fraud."^[11]

[edit] References

[edit] Bibliography

• Gaillard, Y., Pepin, G. , Testing hair for pharmaceuticals, J. Chromatogr. B 733 (1999) 231–246.
• Henderson, G.L., Harkey, M.R., Jones, R.T., "Analysis of Hair for Cocaine", in (eds. Edward. J. Cone, Ph.D., Michael. J. Welch, Ph.D., and M. Beth Grigson Babecki, M.A.), "Hair Testing for Drugs of Abuse: International Research on Standards and Technology", 1995, p. 91-120. NIH Publication No. 95-3727.
• Kintz, P., Bioanalytical procedures for detection of chemical agents in hair in the case of drug-facilitated crimes. Anal Bioanal Chem. 388, 7 (2007) 1467-74.
• Nakahara, Y., Hair analysis for abused and therapeutic drugs, J. Chromatogr. B 733 (1999) 161–180.
• Romolo, F.S., Rotolo, M.C., Palmi, I., Pacifici, R., Lopez, A., Optimized conditions for simultaneous determination of opiates, cocaine and benzoylecgonine in hair samples by GC-MS. Forensic Science International (2003), 138(1-3), 17-26.
• Sachs, H. Kintz, P., Testing for drugs in hair. Critical review of chromatographic procedures since 1992, J. Chromatogr. B 713 (1998) 147–161.

[edit] External links

• Society of Hair Testing
• Article: Hair Drug Testing Bibliography
• Study Questions Reliability of Hair Tests