Sorted By Test Name - Mayo Medical Laboratories

HGU
8592
HG
8618
toxic. Further bioconversion to an alkyl Hg, such as methyl Hg (CH[3]Hg[+]), yields a species of Hg that
is highly selective for lipid-rich tissue, such as the myelin sheath, and is very toxic. Industrial exposure is
a major source of Hg intoxication.
Useful For: Screening potentially exposed workers for mercury toxicity in settings where a 24-hour
collection is problematic
Interpretation: Urinary mercury (Hg) is the most reliable way to assess exposure to inorganic Hg, but
the correlation between the levels of excretion in the urine and clinical symptoms is poor. The reference
interval corresponds to the Occupational Safety and Health Administration (OSHA) guideline for Hg
exposure. The ordering physician will be contacted regarding any result exceeding OSHA thresholds to
determine the level of workplace exposure and follow-up action.
Reference Values:
MERCURY/CREATININE
50 mcg/day indicates significant exposure (per
World Health Organization standard).
Reference Values:
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: 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
Mercury, Blood
Clinical Information: Mercury (Hg) is essentially nontoxic in its elemental form. If Hg(0) is
chemically modified to the ionized, inorganic species, Hg(+2), it becomes toxic. Further bioconversion to
an alkyl Hg, such as methyl Hg (CH[3]Hg[+]), yields a species of mercury that is highly selective for
lipid-rich tissue such as neurons and is very toxic. The relative order of toxicity is: Not Toxic - Hg(0) <
Hg(+2)