Bone lead concentrations assessed by in vivo X-ray fluorescence

The assessment of past chronic lead exposure is difficult. Chronic lead bur den is not always correctly assessed using laboratory-based tests that are useful for acute or recent exposures. We describe a case of suspected chron ic lead exposure that illustrated the need for improved and possibly noninv asive methods to determine cumulative lead body burden. X-Ray fluorescence (XRF) is discussed as a method to obtain in vivo bone lead measurements. We discuss the potential of such measurements as accurate biomarkers of cumul ative exposure and whether XRF can be used for retroactive exposure assessm ent or to predict risk of future health problems. (C) 2000 American Associa tion for Clinical Chemistry.