Hair analysis

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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.

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[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, compairing 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 (Valium-type drugs) and amphetamines. [4] 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.

[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 toxics 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 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."[5]

[edit] Use in occupational, environmental and alternative medicine

Hair analysis has been used in occupational,[6] 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,[7] practioners screen for toxic exposure and heavy metal poisoning. Some advocates claim that they can also diagnose mineral deficiencies and conditions like autism.[8] These uses are often controversial, still evolving and not yet broadly standardized.

See also: Hair analysis (alternative medicine)

[edit] 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. ^ a b Masters RD. Validity of Head Hair Analysis and Methods of Assessing Multiple Chemical Sensitivity. Dartmouth College. accessed 9 Dec 2006.
  3. ^ Dartmouth Toxic Metals Research Program. A Metals Primer. Center for Environmental Health Sciences at Dartmouth. accessed 9 Dec 2006.
  4. ^ 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.
  5. ^ 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.
  6. ^ Niculescu T, Dumitru R, Botha V, Alexandrescu R, Manolescu N.Relationship between the lead concentration in hair and occupational exposure. Br J Ind Med. 1983 Feb;40(1):67-70.
  7. ^ Bass DA, Hickok D, Quig D, Urek K.Trace element analysis in hair: factors determining accuracy, precision, and reliability - Statistical Data Included. Altern Med Review 2001;6(5):472-481.
  8. ^ 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).

[edit] External links

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