Mercury Blood Test

Total mercury in whole blood, measured by inductively coupled plasma mass spectrometry (ICP-MS). In people whose main exposure is fish, blood mercury mostly reflects methylmercury.

People who eat fish often, especially high-mercury species such as swordfish, shark, king mackerel, marlin, orange roughy, tilefish or bigeye tuna; people planning a pregnancy who want to check their exposure; people who have used skin creams, imported remedies or products that may contain mercury; people with possible workplace or household exposure; and people with symptoms such as tingling, coordination problems or vision changes whose clinician wants to rule mercury in or out.

When you are concerned about exposure from diet, products or your environment. Because blood mercury reflects relatively recent exposure, test while the exposure is ongoing or soon after it. Quest asks you to avoid seafood for 48 hours before the draw so that a single recent meal does not skew the result.

Quest reports blood mercury in mcg/L; Quest's reference range for this test is 10 mcg/L or less. A result within that range is typical. A higher result usually reflects frequent consumption of high-mercury fish or another recent exposure, such as mercury-containing products or occupational sources. A single high value does not mean you have mercury poisoning; a clinician will consider your diet, products you use, symptoms such as tingling, coordination problems or vision changes, and may repeat the test or add a urine mercury test if inorganic or metallic mercury exposure is suspected. Review your results with a clinician, especially if you are pregnant or planning a pregnancy.