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'''Hair analysis''' is the chemical analysis of a ] sample. Its most widely accepted use is in the fields of ] and ]. It is also used in ], but this use is controversial and still evolving. '''Hair analysis''' is the chemical analysis of a ] 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.<ref>Eastern Research Group. SUMMARY REPORT, HAIR ANALYSIS PANEL DISCUSSION: EXPLORING THE STATE OF THE SCIENCE. ATDSR. June 12—13, 2001</ref> Its most widely accepted use is in the fields of ] and ]. It is also used in ], but this use is controversial and still evolving.


== Use in forensics == == Use in forensics ==

Revision as of 09:14, 9 December 2006

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. Its most widely accepted use is in the fields of forensics and toxicology. It is also used in alternative medicine, but this use is controversial and still evolving.

Use in forensics

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, compairing hairs found at the scene of the crime with hair samples taken from a suspect.

Use in toxicology

Hair analysis can be used for the detection of many therapeutic drugs and recreational drugs, including cocaine, heroin, benzodiazepines (Valium-type drugs) 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.

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 CDC 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."

Use in alternative medicine

Hair analysis is used in some branches of alternative medicine as a method of investigation to assist diagnosis. The hair is analyzed, looking at the levels of mineral and metals in the hair sample and using the results, as part of a proper examination, advocates claim that they can diagnose mineral deficiencies, heavy metal poisoning and even conditions like autism.

Controversy

A 1985 paper noted several then existant commercial hair analysis services as inconsistent. Wennig has also questioned its viability for use in forensics. Tests have shown that levels of heavy metal in the body may not be reflected by the levels in the hair. When the same sample are sent to different laboratories offering the service results differ from laboratory to laboratory. The latter authors concluded:

"Hair mineral analysis from these laboratories was unreliable, and we recommend that health care practitioners refrain from using such analyses to assess individual nutritional status or suspected environmental exposures. Problems with the regulation and certification of these laboratories also should be addressed."

Tamari wrote in a letter to the editor that this may be the result of lack of standardization in the analysis protocols, rather than a flaw in the concept. In addition, he stated that "any analytical laboratory, whether analyzing hair, blood or urine, has no valid rationale for recommending a supplementation program based solely on the specific analysis. Only a qualified health practitioner, who has all the necessary and appropriate information about the patient, is in the position to make proper interpretation and appropriate recommendations."

References

  1. Eastern Research Group. Section 5, Choosing the Best Biological Marker. SUMMARY REPORT, HAIR ANALYSIS PANEL DISCUSSION: EXPLORING THE STATE OF THE SCIENCE. ATDSR. June 12—13, 2001
  2. Welch, M.J., Sniegoski, L.T., Allgood, C.C., and Habram, M. Hair analysis for drugs of abuse: Evaluation of analytical methods, environmental issues, and development of reference materials. J Anal Toxicol 17(7):389-398, 1993.
  3. PMID: 10468164 Hair concentrations of calcium, iron, and zinc in pregnant women and effects of supplementation. Leung PL, Huang HM, Sun DZ, Zhu MG. Biol Trace Elem Res. 1999 Sep;69(3):269-82.
  4. Lathe, Richard, and Michael Le Page. "Toxic metal clue to autism: a study has revealed startling differences in mercury levels in the hair of autistic and normal children. (This Week)." New Scientist 178.2400 (June 21, 2003): 4(2).
  5. Barrett S. Commercial hair analysis: Science or scam? JAMA 254:1041-1045, 1985.
  6. Wennig, R. "Potential problems with the interpretation of hair analysis results.(Selected Papers from the 2d International Meeting of the Society of Hair Testing)."Forensic Science International 107.1-3 (Jan 10, 2000): 5-12.
  7. Teresa M, Vasconcelos SD, Tavares HM. Trace element concentrations in blood and hair of young apprentices of a technical-professional school. Sci Total Environ. 1997 Oct 20;205(2-3):189-99.
  8. ^ Seidel S, Kreutzer R, Smith D, McNeel S, Gilliss D. Assessment of commercial laboratories performing hair mineral analysis. Journal of the American Medical Association, 2001 Jan 3;285(1):67-72.
  9. George Tamari. Unreliability of hair analysis. Letter to the editor: Townsend Letter for Doctors and Patients, May, 2004

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