Hair analysis
Encyclopedia
Hair analysis may refer to the chemical analysis of a hair
Hair
Hair is a filamentous biomaterial, that grows from follicles found in the dermis. Found exclusively in mammals, hair is one of the defining characteristics of the mammalian class....

 sample, but can also refer to microscopic analysis or comparison. Chemical hair analysis may be considered for retrospective purposes when blood and urine are no longer expected to contain a particular contaminant, typically a year or less. Its most widely accepted use is in the fields of forensic toxicology
Forensic toxicology
Forensic toxicology is the use of toxicology and other disciplines such as analytical chemistry, pharmacology and clinical chemistry to aid medical or legal investigation of death, poisoning, and drug use...

 and, increasingly, environmental toxicology
Toxicology
Toxicology is a branch of biology, chemistry, and medicine concerned with the study of the adverse effects of chemicals on living organisms...

. Several alternative medicine
Alternative medicine
Alternative medicine is any healing practice, "that does not fall within the realm of conventional medicine." It is based on historical or cultural traditions, rather than on scientific evidence....

 fields also use various hair analyses for environmental toxicology
Toxicology
Toxicology is a branch of biology, chemistry, and medicine concerned with the study of the adverse effects of chemicals on living organisms...

 but these uses are controversial, evolving and not standardized.
Hair analysis can refer to the forensic technique of assessing a number of different characteristics of hairs, usually consisting of hairs from "known" sources and those recovered during forensic examinations or "questioned" hairs in order to determine whether they have a common source; for example, comparing hair found at the scene of the crime with hair samples taken from a suspect. Typically, examinations of this type are conducted using stereo-microscope(s) for initial preparation, and a comparison microscope for detailed analysis (comparison).

Use in forensic toxicology

Hair analysis is also used for the detection of many therapeutic drugs and recreational drugs, including cocaine
Cocaine
Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...

, heroin, benzodiazepines and amphetamines. 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.

Drug test

Hair samples are increasingly being used to detect the presence of illegal drugs
Illegal drug trade
The illegal drug trade is a global black market, dedicated to cultivation, manufacture, distribution and sale of those substances which are subject to drug prohibition laws. Most jurisdictions prohibit trade, except under license, of many types of drugs by drug prohibition laws.A UN report said the...

 both by the state and also by private employers who test their employees. 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. The judicial admissibility of the test is guided by the Daubert standard
Daubert Standard
The Daubert standard is a rule of evidence regarding the admissibility of expert witnesses' testimony during United States federal legal proceedings. Pursuant to this standard, a party may raise a Daubert motion, which is a special case of motion in limine raised before or during trial to exclude...

. A precedent of national reference has been United States v. Medina, 749 F.Supp. 59 (E.D.N.Y.1990).

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.

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.

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
Ludwig van Beethoven
Ludwig van Beethoven was a German composer and pianist. A crucial figure in the transition between the Classical and Romantic eras in Western art music, he remains one of the most famous and influential composers of all time.Born in Bonn, then the capital of the Electorate of Cologne and part of...

's hair have been conducted in conjunction with the National Institutes of Health
National Institutes of Health
The National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...

, and Centers for Disease Control and Prevention
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...

 to name a few.

A 1999 study on hair concentrations of calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

, iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

, and zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

 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."

Use in occupational, environmental and alternative medicine

Hair analysis has been used in occupational, environmental
Environmental medicine
Environmental medicine is a multidisciplinary field involving medicine, environmental science, chemistry and others. It may be viewed as the medical branch of the broader field of environmental health. The scope of this field involves studying the interactions between environment and human health,...

 and some branches of alternative medicine
Alternative medicine
Alternative medicine is any healing practice, "that does not fall within the realm of conventional medicine." It is based on historical or cultural traditions, rather than on scientific evidence....

 as a method of investigation to assist screening and/or diagnosis
Medical diagnosis
Medical diagnosis refers both to the process of attempting to determine or identify a possible disease or disorder , and to the opinion reached by this process...

. 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, practitioners screen for toxic exposure and heavy metal poisoning
Heavy Metal Poisoning
Heavy Metal Poisoning is a song by American rock band Styx. It was included as the fifth track on their 1983 studio album Kilroy Was Here.The song in the story of Kilroy Was Here has the character of Dr Righteous preaching the evils of rock and roll...

. Some advocates claim that they can also diagnose mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

 deficiencies and that people with autism
Autism
Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...

have unusual hair mineral contents. 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."
A recent review of scientific literature by Dr Kempson highlighted analysis of metals/minerals in hair can be applied in large population studies for researching epidemiology and groups of chronically exposed populations, however any attempt to provide a diagnosis based on hair for an individual is not possible. An exception to this can be in advanced analyses for acute poisoning.

External links

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