Harvard T.H. Chan School of Public Health, 655 Huntington Ave Building 1 Rm 1402, Boston 02115-5724, Massachusetts, United States.
Department of Neurology, Boston Children's Hospital, Boston 02115-5724, Massachusetts, United States.
Environ Sci Technol. 2021 Apr 20;55(8):5050-5055. doi: 10.1021/acs.est.0c06622. Epub 2021 Mar 24.
Collecting blood spots from newborns is a common procedure used to diagnose multiple health conditions. Fingerstick blood samples are routinely collected from children to diagnose elevated blood lead levels. In our study, we wanted to test the feasibility of using a high-power energy-dispersive X-ray fluorescence (EDXRF) device to accurately measure the concentration of lead in blood spots. We created spotted standards of a known concentration of lead on a filter paper at different volumes and concentrations. We determined the detection limit for lead through repeated measurements of our standards and calibration line slopes. We also tested the variability of the measured lead concentration across procedures and spotted blood volumes and found no significant additions to uncertainty in measurements. Finally, we compared blood lead concentrations measured by EDXRF and atomic absorption spectroscopy (AAS) and found EDXRF to be a significant predictor of blood lead ( = 22, R = 0.98, value <0.001) with an average detection limit of 1.7 μg/dL of blood lead. This detection limit is similar to that of the AAS technique, which is commonly used in clinical testing laboratories for blood lead surveillance. These findings provide a proof of concept that blood spots measured by EDXRF may be used as a surveillance tool for lead exposure, even at elevated blood lead levels of 2-3 μg/dL.
从新生儿采集血斑是一种用于诊断多种健康状况的常见方法。通常从儿童采集指尖血样，以诊断血铅水平升高。在我们的研究中，我们想测试使用高功率能量色散 X 射线荧光（EDXRF）设备准确测量血斑中铅浓度的可行性。我们在不同体积和浓度的滤纸上创建了已知浓度的铅斑点标准。我们通过对标准和校准线斜率的重复测量来确定铅的检测限。我们还测试了测量过程和斑点血容量对测量铅浓度的可变性，发现测量不确定度没有显著增加。最后，我们比较了 EDXRF 和原子吸收光谱法（AAS）测量的血铅浓度，发现 EDXRF 是血铅的重要预测因子（=22，R=0.98， 值<0.001），平均检测限为 1.7μg/dL 的血铅。该检测限与 AAS 技术相似，后者常用于临床检测实验室进行血铅监测。这些发现提供了一个概念验证，即 EDXRF 测量的血斑可用作铅暴露的监测工具，即使在 2-3μg/dL 的血铅水平升高时也是如此。
