Detection of nonacute arsenic exposure in hair specimens
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)
Arsenic (As)
As (Arsenic)
Hair
Question ID | Description | Answers |
---|---|---|
ASHSC | Specimen Source |
Head Pubic Axillary Scalp |
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 in Special Instructions.
Additional Information: If known, indicate source of hair (axillary, head, or pubic).
0.05 g
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Hair | Ambient (preferred) | ||
Frozen | |||
Refrigerated |
Detection of nonacute arsenic exposure in hair specimens
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.
0-15 years: not established
> or =16 years: <1.0 mcg/g of hair
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.
1. Sthiannopkao S, Kim K-W, Cho KH, et al: Arsenic levels in human hair, Kandal Province, Cambodia: The influences of groundwater arsenic, consumption period, age and gender. Applied Geochemistry 2010;25:81-90
2. Pearse DC, Dowling K, Gerson AR, et al: Arsenic microdistribution and speciation in toenail clippings of children living in a historic gold mining area. Sci Total Environ 2010;408:2590-2599
Arsenic, mercury, and lead in hair are analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) in kinetic energy discrimination (KED) mode using gallium, iridium, and lutetium as internal standards, and a salt matrix calibration.(Unpublished Mayo method)
Tuesday
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.
82175
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
ASHA | Arsenic, Hair | 5584-8 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
31896 | Arsenic, Hair | 5584-8 |
ASHSC | Specimen Source | 31208-2 |