Lead is primarily measured in which medium?

Lead is primarily measured in whole blood because lead particles circulate within the bloodstream and can be effectively captured and quantified in this medium. Blood contains both red blood cells and plasma, where lead can exist in various forms, but the assessment in whole blood gives a comprehensive picture of recent exposure to lead, reflecting both ongoing exposure and the body burden of the metal.

Measuring lead in whole blood is the recommended approach for evaluating lead exposure because lead tends to accumulate in the erythrocytes and is also distributed in the plasma. Therefore, whole blood assays are considered the gold standard for diagnosing lead intoxication and assessing an individual's exposure level.

Other mediums, such as serum, plasma, or cerebrospinal fluid (CSF), are not typically used for lead measurement because they do not provide as reliable an index of lead exposure as whole blood does. Serum and plasma measurements could potentially miss lead that is retained within cells or could show levels that do not correlate well with acute or chronic exposure. CSF is generally not a relevant medium for lead measurement since lead does not effectively cross the blood-brain barrier under normal circumstances and is not an appropriate indicator of systemic lead exposure.