Mercury, Whole Blood

Monitor exposure to mercury.

Blood mercury levels may be elevated due to the presence of inorganic mercury and/or organic mercury compound (eg, ethylmercury and methylmercury). These alkylmercury compounds are generally not used in industry but are considered more toxic to humans than inorganic mercury.

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Acute and chronic mercury poisoning affects the kidneys, central nervous system, and the gastrointestinal tract. The three telltale symptoms of mercury poisoning are impaired articulation, irregularity of muscular action, and constricted visual fields. Mercury poisoning through chronic exposure to metallic and inorganic forms of mercury generally produces nervousness, lassitude, tremor, and mucous membrane irritation. Inorganic mercury poisoning is associated primarily with peripheral effects, including gastroenteritis and tubular nephritis, whereas organic compounds predominantly affect the central nervous system (CNS) and effects may be severe and irreversible.2

Chronic inorganic mercury poisoning is an occupational disease of smelters, mercury miners, gilders, and factory workers. Inhalation of mercury vapors may lead to pneumonitis, cough, fever, and other pulmonary symptoms. The most reliable way to measure exposure to inorganic mercury is to measure urinary mercury levels. Correlation between urine levels and symptoms is poor, however.

The most common nonindustrial source of mercury poisoning is the consumption of methyl mercury-contaminated fish. Organic mercury poisoning is best detected in whole blood, as this form of mercury is located mainly in the RBCs. Organic mercury poisoning may develop quickly and is usually a more serious disease. Studies conducted by the CDC3 found that approximately 6% of childbearing-age women had levels at or above a reference dose, an estimated level assumed to be without appreciable harm (>5.8 μg/L). Women who are pregnant or who intend to become pregnant should follow federal and state advisories on consumption of fish.

Additional general population exposure to mercury is from coal-fired power plants where an estimated 75 tons of mercury are emitted into the atmosphere each year.4

BEI® are reference values intended as guidelines for evaluation of occupational exposure. BEI® represent biological levels of chemicals that correspond to workers with inhalation exposure equivalent to the threshold limit value (TLV®) of the chemicals. TLV®s refer to the airborne concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed, day after day, without adverse health effects.5
1. BEI® (Biological Exposure Indices) based on 2010 Recommendations of the American Conference of Governmental Industrial Hygienists (ACGIH).

2. Baselt RC, Cravey RH. Disposition of Toxic Drugs and Chemicals in Man. 4th ed. Chemical Toxicology Institute;1995.

3. CDC Morbidity and Mortality Weekly Report. 53(43), November 5, 2004.

4. EPA. http://www.epa.gov/mercury/control_emissions/index.htm. Accessed September 9, 2006.

5. TLVs and BEIs, Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices 2010, American Conference of Governmental Industrial Hygienists (ACGIH).

Jacobs DS, DeMott WR, Oxley DK, et al. Laboratory Test Handbook With Key Word Index. 5th ed. Hudson, Ohio: Lexi-Comp Inc; 2001.