Table 2.

Possible Biomarkers for Metal Assessment as Part of Clinical Practice for Cardiovascular Disease Protection

Metal	Specimen (half‐life)	Method	Additional information	Possible reference value for adults
Lead	Blood (30–100 d)* Bone (decades) Postchelation urine (decades) †	ICPMS K‐shell XRF ICPMS	Blood is the common marker Postchelation urine is an established measure of total body burden	3.5 μg/dL (similar to children) … …
Cadmium	Blood (30–100 d)* Urine (decades) Postchelation urine (unknown) †	ICPMS ICPMS ICPMS	Smokers have markedly high levels	1.0 μg/L both blood and urine‡ (based on NHANES)
Arsenic	Urine (1–30 d) Toenail (weeks of exposure 6 prior mo)	ICPMS ICPMS or nuclear activation analysis	Avoid seafood for 7 d before sample Measurement error is large	5 μg/L (based on water standards) ‡ …

ICPMS indicates inductively coupled plasma mass spectrometry; NHANES, National Health and Nutrition Examination Survey; and XRF, x‐ray fluorescence.

^*Reflects both exogenous and endogenous exposure from bone and other tissues.

^† Chelating agents for lead are intravenous (EDTA) or oral (dimercaptosuccinic acid [succimer]); the chelatable urine lead is considered a marker of lead body burden. Intravenous EDTA also chelates cadmium, however, whether postchelation urine cadmium reflects total cadmium body burden is not established.

^‡ First morning urine void (for spot urine samples, report per gram of creatinine). For cadmium, this limit is around 3 times the geometric mean in urine in NHANES (similar for blood). For arsenic, the measure of total arsenic requires no seafood in the preceding 7 days or using arsenic speciation (sum inorganic and methylated species). The possible guideline is proposed on the basis of the drinking water standard in New Jersey and New Hampshire and that the ratio in water and urine is 1.