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Test Code LABHMSUO Heavy Metals Screen Occupational Exposure, Urine

Additional Codes

Test Name in EPIC

EPIC Test Code

Mnemonic Mayo Test ID


Reporting Name

Heavy Metals Scrn Occ Exposure, U

Useful For

Screening potentially exposed workers for heavy metal toxicity in settings where a 24-hour collection is problematic

Profile Information

Test ID Reporting Name Available Separately Always Performed
CDCR Creatinine Conc No Yes
ARCO As Conc No Yes
PBCO Pb Conc No Yes
CDUOM Cd Conc Yes, (order CDU) Yes
HGCO Hg Conc Yes, (order HGOM) Yes

Method Name

CDCR: Enzymatic Colorimetric Assay

ARCO, PBCO, CDUOM, HGCO: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Specimen Required

Collection Container/Tube: Clean, plastic urine collection container

Submission Container/Tube: Plastic, 5-mL tube (T465) or a clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a random urine specimen.

2. Shake specimen gently.

3. See Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.

Additional Information:

1. Patient should not eat seafood for a 48-hour period prior to start of collection.

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

Specimen Minimum Volume

5 mL

Specimen Stability Information

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

Reject Due To









Reference Values


<50 mcg/g



<35 mcg/g



<3.0 mcg/g



<5 mcg/g

Day(s) and Time(s) Performed

Monday through Friday; 7 p.m., Saturday; 2 p.m.

CPT Code Information





82570 Creatinine

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HMSUO Heavy Metals Scrn Occ Exposure, U In Process


Result ID Test Result Name Result LOINC Value
CDCR Creatinine Conc 2161-8
21670 As Conc 5586-3
860 Cd Conc 5611-9
21667 Hg Conc 5689-5
21673 Pb Conc 5676-2
21674 Pb/Creatinine Ratio 13466-8
21679 Hg/Creatinine Ratio 13465-0
7242 Cd/Creatinine Ratio 13471-8
21671 As/Creatinine Ratio 13463-5
21668 Inorganic As/Cr Ratio 13825-5

Specimen Retention Time

14 days

Method Description

See individual test descriptions for:

-ASCRU / Arsenic/Creatinine Ratio, Random, Urine

-PBCRU / Lead/Creatinine Ratio, Random, Urine

-CDOM / Cadmium Occupational Monitor, Urine

-HGOM / Mercury Occupational Monitor, Urine

Analytic Time

1 days


Nitric acid cannot be added to either the collection or aliquot container. Nitrate interferes with the extraction procedure that would need to take place in the event of a positive arsenic result.


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


This test is intended for use as a screening tool for occupational monitoring. It is not a replacement of HMSU / Heavy Metals Screen, 24 Hour, Urine.

Clinical Information

Arsenic (As), lead (Pb), cadmium (Cd), and mercury (Hg) are well-known toxins and toxic exposures are characterized by increased urinary excretion of these metals.


Arsenic exists in a number of different forms; some are toxic while others are not. Toxic forms, which are typically encountered as a result of an industrial exposure, are the inorganic species As (+3) (As-III) and As (+5) (As-V) and the partially detoxified metabolites, monomethylarsine and dimethylarsine. The 2 most common nontoxic forms are arsenobetaine and arsenocholine. Arsenic toxicity affects a number of organ systems.


Lead toxicity primarily affects the gastrointestinal, neurologic, and hematopoietic systems.


Chronic exposure to cadmium causes accumulated renal damage.


Mercury is essentially nontoxic in its elemental form. However, once it is chemically modified to the ionized, inorganic species, Hg(++), it becomes toxic. Further bioconversion to an alkyl mercury, such as methyl Hg (CH[3]Hg[+]), yields a species of mercury that is highly selective for lipid-rich tissue, such as the myelin sheath, and is very toxic.


The reference intervals for this test are Occupational Safety and Health Adminstration (OSHA) thresholds.


The ordering physician will be contacted regarding any result exceeding OSHA thresholds to determine the level of workplace exposure and follow-up action.


Arsenic results exceeding the OSHA threshold will be fractionated to confirm the presence of toxic forms.


Measurement of urine excretion rates either before or after chelation therapy has been used as an indicator of lead exposure. However, blood lead analysis has the strongest correlation with toxicity.


Normally, the excretion of cadmium is proportional to creatinine. When renal damage has occurred, cadmium excretion increases relative to creatinine.


The correlation between the levels of mercury in the urine and clinical symptoms is poor, but urinary mercury is the most reliable way to assess exposure to inorganic mercury.

Test Classification

See Individual Test IDs