Temporal Stability of Blood Lead Concentrations in Adults Exposed Only to Environmental Lead

Abstract

1 The temporal stability of blood lead concentrations of 21 healthy adults (14 men and 7 women) exposed only to environmental lead was assessed by analysis of 253 blood specimens collected serially over periods from 7 to 11 months. 2 Improved analytical sensitivity allowed detection of small (< 1.0 μg/ 100 ml) changes in blood lead concentrations and both within- and between-run analytical errors were minimized by a strict internal quality control protocol. 3 The women had lower blood lead concentrations (mean 8.5, range 7.4-10.8 μg/100 ml) than did the men (mean 12.2, range 8.6-15.8 μg/100 ml). These are within the expected ranges for non-occupationally exposed persons. 4 Blood lead concentrations in the serial specimens from both men and women changed very little over the study period, with standard deviations of < 0.5 μg/100 ml for the majority of individual mean concentrations: for all except two subjects the standard deviations were < 0.8 μg/100 ml. 5 Two subjects showed significant changes in blood lead concentrations during the study (standard deviations of mean > 1.0 μg/100 ml). A temporary increase in oral lead intake was identified for one of these subjects. 6 In the absence of substantial changes in lead exposure blood lead levels in adults are remarkably stable and for their environmental monitoring a single blood lead concentration is an excellent biological indicator.