At a glance
Also known as
Why get tested?
To detect excessive exposure to mercury
When to get tested?
When you have symptoms of mercury poisoning, to evaluate a known exposure to mercury, or to monitor occupational exposure to mercury
A blood sample drawn from a vein in your arm and/or a urine collection
What is being tested?
Mercury is an element that exists in three forms: as a free metallic (liquid or vapour), an inorganic compound (mercury salt), and as a variety of organic compounds (methyl mercury). It has no known function in normal metabolism but is able to bind to a number of proteins, interfering with their function.
Mercury has been used in medicine for centuries and may be found in small quantities throughout the environment. It is released by the breakdown of minerals in rocks and soils and as a byproduct of fossil fuel combustion and waste incineration. Microorganisms that live in marine and freshwater sediments methylate mercury and this methyl mercury is concentrated up the food chain and can be present in higher concentrations in top predators such as swordfish or tuna.
Metallic mercury is readily absorbed by inhalation whereas little is absorbed after ingestion. Inorganic compounds are also poorly absorbed from the gut. Organic mercury compounds are absorbed very well from either the lungs or the gut. Phenyl mercuric compounds (used in fungicides) may be absorbed through the skin. Organic mercury is excreted in bile, while inorganic and metallic mercury are excreted via urine.
The small amounts of mercury the general population are exposed to do not generally cause health concerns but people who are exposed to dangerous concentrations or are exposed chronically to mercury (such as those who work with 'heavy metals' in their occupation) may have mercury-related symptoms and complications.
The amount of mercury absorbed by an individual and its effects on their health depends on the type of mercury, its concentration, and the exposure time.
Once mercury is absorbed, it is distributed throughout the body, with the majority accumulating in the kidneys and brain. Mercury has a biological half-life of about 60 days, with most being excreted in the urine.
Pregnant women with elevated levels of mercury can pass it on to their foetus, affecting development especially the foetus's brain, kidneys, and nerves. Mercury can be passed from mother to baby through breast milk during nursing.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm or a or may be collected.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed. Consult your doctor or laboratory about urine collection to avoid sample contamination.