A Bland-Altman Comparison of the Lead Care® System and Inductively Coupled Plasma Mass Spectrometry for Detecting Low-Level Lead in Child Whole Blood Samples

Chronic childhood lead exposure, yielding blood lead levels consistently below 10 mu g/dL, remains a major public health concern. Low neurotoxic effect thresholds have not yet been established. Progress requires accurate, efficient, and cost-effective methods for testing large numbers of children. The LeadCare (R) System (LCS) may provide one ready option. The comparability of this system to the gold standard method of inductively coupled plasma mass spectrometry (ICP-MS) for the purpose of detecting blood lead levels below 10 mu g/dL has not yet been examined. Paired blood samples from 177 children ages 5.2-12.8 years were tested with LCS and ICP-MS. Triplicate repeat tests confirmed that LCS and ICP-MS had comparable repeatability. As compared with ICP-MS, LCS had a negative bias of 0.457 mu g/dL with an average variability of 1.0 mu g/dL. The reproducibility and precision of the LCS is appropriate for the evaluation and monitoring of blood lead levels of individual children in a clinical setting. Recent research however has suggested that increments as small as 0.5 mu g/dL may distinguish those at risk of low-level lead-induced neurotoxicity. Thus, we also conclude that the LCS is not useful for research applications attempting to identify neurotoxic effect thresholds for chronic lowest level lead exposure in children. For these typ es of research applications, a convenient and low-cost device is needed for the precise detection of child blood lead levels below 10 mu g/dL.