Mercury, 24 Hour, Urine
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The correlation between the levels of mercury (Hg) excretion in the urine and the clinical symptoms is considered poor. However, urinary Hg is the most reliable way to assess exposure to inorganic Hg.
For additional information, see #8618 "Mercury, Blood."
Detecting mercury toxicity
Daily urine excretion of mercury >50 mcg/day indicates significant exposure (per World Health Organization standard).
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
To avoid contamination by dust, specimen should be collected away from the site of suspected exposure.
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.
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: 0-9 mcg/specimen
Toxic concentration: >50 mcg/specimen
The concentration at which toxicity is expressed is widely variable between patients. 50 mcg/specimen is the lowest concentration at which toxicity is usually apparent.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. 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
2. 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