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Epic Code LAB2111695 Mercury, 24 Hour, Urine

Additional Codes

Mayo Code: HGU

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Detecting mercury toxicity in 24-hour urine specimens

Specimen Type

Urine
Laboratory Test Directory Note:

Refrigeration during and after urine collection is the preferred means of urine preservation.


Necessary Information


24-Hour volume (in milliliters) is required.



Specimen Required


Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metal tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.

Supplies: Urine Tubes, 10 mL (T068)

Collection Container/Tube: Clean, plastic urine container with no metal cap or glued insert

Submission Container/Tube: Plastic, 10-mL urine tube or a clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 10 mL

Collection Instructions:

1. Collect urine for 24 hours.

2. Refrigerate specimen within 4 hours of completion of 24-hour collection.

3. See Metals Analysis Specimen Collection and Transport for complete instructions.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.


Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 7 days
  Frozen  7 days

Urine Preservative Collection Options

Note: The addition of preservative or application of temperature controls must occur within 4 hours of completion of the collection.

Ambient

No

Refrigerate

Preferred

Frozen

OK

50% Acetic Acid

OK

Boric Acid

No

Diazolidinyl Urea

No

6M Hydrochloric Acid

OK

6M Nitric Acid

OK

Sodium Carbonate

No

Thymol

No

Toluene

No

 

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Day(s) Performed

Monday through Friday

Reference Values

0-17 years: Not established

≥18 years: <2 mcg/24 h

Toxic concentration: >50 mcg/24 h

The concentration at which toxicity is expressed is widely variable between patients. 50 mcg/24 h is the lowest concentration at which toxicity is usually apparent.

Clinical Information

The correlation between the levels of mercury (Hg) excretion in the urine and the clinical symptoms is considered poor.

 

Previous thought indicated urine as a more appropriate marker of inorganic mercury because organic mercury represented only a small fraction of urinary mercury. Based on possible demethylation of methylmercury within the body, urine may represent a mixture of dietary methylmercury and inorganic mercury. Seafood consumption can contribute to urinary mercury levels (up to 30%),(1) which is consistent with the suggestion that due to demethylation processes in the human body, a certain proportion of urinary mercury can originate from dietary consumption of fish/seafood.(2)

 

For more information see HG / Mercury, Blood.

Cautions

To avoid contamination by dust, specimen should be collected away from the site of suspected exposure.

Interpretation

Daily urine excretion of mercury above 50 mcg/day indicates significant exposure (per World Health Organization standard).

Reporting Name

Mercury, 24 Hr, U

Method Name

Triple Quadrupole Inductively Coupled Plasma-Mass Spectrometry (ICP-MS/MS)

Method Description

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

CPT Code Information

83825

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HGU Mercury, 24 Hr, U 6693-6

 

Result ID Test Result Name Result LOINC Value
8592 Mercury, 24 Hr, U 6693-6
TM5 Collection Duration 13362-9
VL3 Urine Volume 3167-4

Report Available

1 to 3 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.

Clinical Reference

1. Snoj Tratniid J, Falnoga I, Mazej D, et al: Results of the first national human biomonitoring in Slovenia: Trace elements in men and lactating women, predictors of exposure and reference values. Int J Hyg Environ Heatlh. 2019 Apr;222(3):563-582

2. Sherman LS, Blum JD, Franzblau A, Basu N: New insights into biomarkers of human mercury exposure using naturally occurring mercury stable isotopes. Envrn Sci Technol. 2013 Apr 2;47(7):3403-3409

3. Lee R, Middleton D, Caldwell K, et al: A review of events that expose children to elemental mercury in the United States. Environ Health Perspect. 2009 Jun;117(6):871-878

4. Bjorkman L, Lundekvam BF, Laegreid T, et al: Mercury in human brain, blood, muscle and toenails in relation to exposure: an autopsy study. Environ Health. 2007 Oct 11;6:30

5. Bernhoft RA. Mercury toxicity and treatment: a review of the literature. J Environ Public Health. 2012;2012:460508. doi: 10.1155/2012/460508

6. Strathmann FG, Blum LM: Toxic elements. In: Rifai N, Chiu RWK, Young I, Burnham CD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 44