What does the Mercury (Blood) test measure?

Why is Mercury (Blood) measured?

Blood mercury is the primary marker for methylmercury from fish and shellfish, which crosses the blood–brain barrier and accumulates in the central nervous system. Elevated concentrations may signal neurotoxic risk, particularly in pregnant women and children, and prompt dietary counselling or source identification.

Reference ranges

Standard reference

Background population typically <10 µg/L; occupational and toxicological thresholds are higher.

Functional medicine optimal

Regulatory fish-consumption advisories and occupational limits typically correspond to blood mercury below 5–10 µg/L; lower levels are preferred in pregnancy and paediatric populations.

Units

µg/L, nmol/L

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.