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Test Code HMHA Heavy Metals, Hair

Reporting Name

Heavy Metals, Hair

Useful For

Detection of nonacute arsenic, mercury, and lead exposure using hair specimens

Profile Information

Test ID Reporting Name Available Separately Always Performed
ASHA Arsenic, Hair Yes Yes
PBHA Lead, Hair Yes Yes
HGHAR Mercury, Hair Yes Yes

Method Name

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Hair


Necessary Information


Indicate source of hair (axillary, head, or pubic), if known



Specimen Required


Supplies: Hair and Nails Collection Kit (T565)

Specimen Volume: 0.2 g

Collection Instructions: Prepare and transport specimen per the instructions in kit or see Collecting Hair and Nails for Metals Testing.


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.

Reference Values

ARSENIC

0-15 years: Not established

≥16 years: <1.0 mcg/g of hair

 

LEAD

<4.0 mcg/g of hair

Reference values apply to all ages.

 

MERCURY

0-15 years: Not established

≥16 years:<1.0 mcg/g of hair

Day(s) Performed

Tuesday

CPT Code Information

82175-ASHA

83655-PBHA

83825-HGHAR

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HMHA Heavy Metals, Hair 34667-6

 

Result ID Test Result Name Result LOINC Value
31896 Arsenic, Hair 5584-8
31900 Mercury, Hair 5686-1
31898 Lead, Hair 5673-9
PBHSC Specimen Source 31208-2
HGHSC Specimen Source 31208-2
ASHSC Specimen Source 31208-2

Clinical Information

ARSENIC

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 hairs are used to document long-term (6 months-1 year) exposure.

 

MERCURY

Once absorbed and circulating, mercury becomes bound to numerous proteins, including keratin. The concentration of mercury in hair correlates with the severity of clinical symptoms. If the hair can be segregated by length, such an exercise can be useful in identifying the time of exposure.

 

LEAD

Hair analysis for lead can be used to corroborate blood analysis or to document past lead exposure. If the hair is collected and segmented in a time sequence (based on length from root), the approximate time of exposure can be assessed.

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.

 

ARSENIC

Hair arsenic levels above 1.00 mcg/g dry weight may indicate 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, which was the cause of death.

 

MERCURY

Normally, hair contains less than 1 mcg/g of mercury; any amount more than this indicates that exposure to more than normal amounts of mercury may have occurred.

 

LEAD

Normal hair lead content is below 4.0 mcg/g. While hair lead content above 10.0 mcg/g may indicate significant lead exposure, hair is also subject to potential external contamination with environmental lead and contaminants in artificial hair treatments (eg, dyeing, bleaching, or permanents). Ultimately, the hair lead content needs to be interpreted in addition to the overall clinical scenario including symptoms, physical findings, and other diagnostic results when determining further actions.

Cautions

No significant cautionary statements

Method Description

The metals of interest are analyzed by inductively coupled plasma mass spectrometry.(Unpublished Mayo method)

Report Available

2 to 8 days

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.