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HelpTest ID HMNA Heavy Metals, Nails
Reporting Name
Heavy Metals, NailsUseful For
Detection of nonacute arsenic, mercury, and lead exposure
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| ASNA | Arsenic, Nails | Yes | Yes |
| PBNA | Lead, Nails | Yes | Yes |
| HGNA | Mercury, Nails | Yes | Yes |
Specimen Type
NailNecessary Information
Indicate source of nails (fingernails or toenails), if known
Specimen Required
Supplies: Hair and Nails Collection Kit (T565)
Specimen Volume: 0.2 g
Collection Instructions:
1. Prepare and transport specimen per the instructions in the kit or see Collecting Hair and Nails for Metals Testing.
2. Clippings should be taken from all 10 fingernails or toenails.
Specimen Minimum Volume
0.05 g
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Nail | Ambient (preferred) | ||
| Frozen | |||
| Refrigerated | |||
Special Instructions
Reference Values
ARSENIC
0-15 years: not established
≥16 years: <1.0 mcg/g of nails
LEAD
<4.0 mcg/g of nails
Reference values apply to all ages.
MERCURY
0-15 years: not established
≥16 years: <1.0 mcg/g of nails
Day(s) Performed
Tuesday
Test Classification
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.CPT Code Information
82175-Arsenic
83655-Lead
83825-Mercury
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| HMNA | Heavy Metals, Nails | 94574-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 2535 | Arsenic, Nails | 8157-0 |
| 2509 | Mercury, Nails | 8204-0 |
| 2506 | Lead, Nails | 8202-4 |
| PBNSC | Specimen Source | 31208-2 |
| HGNSC | Specimen Source | 31208-2 |
| ASNSC | 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 nails is higher than in other tissues.
Several weeks after exposure, transverse white striae, called Mees' lines, may appear in the fingernails
Mercury
Once absorbed and circulating, mercury becomes bound to numerous proteins, including keratin. The concentration of mercury in nails correlates with the severity of clinical symptoms. If the nails can be segregated by length, such an exercise may be useful in identifying the time of exposure.
Lead
Nail analysis of lead can be used to corroborate blood analysis.
Interpretation
Nails grow at a rate of approximately 0.1 inch/month. Nail keratin synthesized today will grow to the distal end in approximately 6 months. Thus, a nail specimen collected at the distal end represents exposure of 6 months ago.
ARSENIC
Nail arsenic above 1.0 mcg/g dry weight may indicate excessive exposure. It is normal for some arsenic to be present in nails, as everybody is exposed to trace amounts of arsenic from the normal diet.
The highest hair or nail 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, nails contain less than 1 mcg/g of mercury; any amount above this indicates that exposure to more than normal amounts of mercury may have occurred.
LEAD
Normally, the nail lead content is below 4.0 mcg/g. While nail lead content above 10.0 mcg/g may indicate significant lead exposure, nails are also subject to potential external contamination with environmental lead. Ultimately, the nail 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
Clinical Reference
1. Hindmarsh JT, McCurdy RF: Clinical and environmental aspects of arsenic toxicity. Crit Rev Clin Lab Sci. 1986;23:315-347
2. Strumylaite L, Ryselis S, Kregzdyte R: Content of lead in human hair from people exposed to lead. Int J Hyg Environ Health. 2004;207:345-351
3. Barbosa F, Tanus-Santos J, Gerlach R, Parsons P: A critical review of biomarkers used for monitoring human exposure to lead: advantages, limitations, and future needs. Environ Health Perspect. 2005;113:1669-1674
4. Sanna E, Liguori A, Palmes L, et al: Blood and hair lead levels in boys and girls living in two Sardinian towns at different risks of lead pollution. Ecotoxicol Environ Saf. 2003;500:293-299
5. DiPietro ES, Phillips DL, Paschal DC, Neese JW. Determination of trace elements in human hair. Biol Trace Elem Res. 1989;22:83-100
6. Strathmann FG, Blum LM: Toxic elements. In: Nader R, Horwath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 42
Method Description
Arsenic, mercury, and lead in nails 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)
Report Available
2 to 8 daysReject Due To
| All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Method Name
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)