TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: ASHA    
Arsenic, Hair

Useful For Suggests clinical disorders or settings where the test may be helpful

Detection of nonacute arsenic exposure in hair specimens

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

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.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

0-15 years: not established

> or =16 years: <1.0 mcg/g of hair

Interpretation Provides information to assist in interpretation of the test results

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.

Clinical Reference Recommendations for in-depth reading of a clinical nature

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

Special Instructions Library of PDFs including pertinent information and forms related to the test