Test Code ASHA Arsenic, Hair
Reporting Name
Arsenic, HairUseful For
Detection of nonacute arsenic exposure in hair specimens
Method Name
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
HairSpecimen Required
Supplies: Hair and Nails Collection Kit (T565)
Specimen Volume: 0.2 g
Collection Instructions: Prepare and transport specimen per the instructions in the kit or see Collecting Hair and Nails for Metals Testing.
Additional Information: If known, indicate source of hair (axillary, head, or pubic).
Specimen Minimum Volume
0.05 g
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Hair | Ambient (preferred) | ||
Frozen | |||
Refrigerated |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Special Instructions
Reference Values
0-15 years: Not established
≥16 years: <1.0 mcg/g of hair
Day(s) Performed
Tuesday
CPT Code Information
82175
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
ASHA | Arsenic, Hair | 5584-8 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
31896 | Arsenic, Hair | 5584-8 |
ASHSC | Specimen Source | 31208-2 |
Clinical Information
Arsenic circulating in the blood will bind to protein by formation of a covalent complex with sulfhydryl groups of the amino acid cysteine. Keratin, the major structural protein in hair and nails, contains many cysteine residues and, therefore, is one of the major sites for accumulation of arsenic. Since arsenic has a high affinity for keratin, the concentration of arsenic in hair is higher than in other tissues.
Arsenic binds to keratin at the time of exposure, "trapping" the arsenic in hair. Therefore, hair analysis for arsenic is not only used to document that an exposure occurred, but when it occurred. Hair collected from the nape of the neck can be used to document recent exposure. Axillary or pubic hair is used to document long-term (6 months-1 year) exposure.
Interpretation
Hair grows at a rate of approximately 0.5 inch/month. Hair keratin synthesized today will protrude through the skin in approximately 1 week. Thus, a hair specimen collected at the skin level represents exposure of 1 week ago, 1 inch distally from the skin represents exposure 2 months ago, etc.
Hair arsenic levels above 1.00 mcg/g dry weight may indicates excessive exposure. It is normal for some arsenic to be present in hair, as everybody is exposed to trace amounts of arsenic from the normal diet.
The highest hair arsenic observed at Mayo Clinic was 210 mcg/g dry weight in a case of chronic exposure that was the cause of death.
Cautions
Cosmetic and hair dyes can be a potential source of heavy metal contamination.
Method Description
The metal of interest is analyzed by inductively coupled plasma mass spectrometry.(Unpublished Mayo method)