Zartarian Valerie, Xue Jianping, Tornero-Velez Rogelio, Brown James
U.S. Environmental Protection Agency, Office of Research and Development , Research Triangle Park, North Carolina, USA.
Environ Health Perspect. 2017 Sep 12;125(9):097009. doi: 10.1289/EHP1605.
Drinking water and other sources for lead are the subject of public health concerns around the Flint, Michigan, drinking water and East Chicago, Indiana, lead in soil crises. In 2015, the U.S. Environmental Protection Agency (EPA)'s National Drinking Water Advisory Council (NDWAC) recommended establishment of a "health-based, household action level" for lead in drinking water based on children's exposure.
The primary objective was to develop a coupled exposure-dose modeling approach that can be used to determine what drinking water lead concentrations keep children's blood lead levels (BLLs) below specified values, considering exposures from water, soil, dust, food, and air. Related objectives were to evaluate the coupled model estimates using real-world blood lead data, to quantify relative contributions by the various media, and to identify key model inputs.
A modeling approach using the EPA's Stochastic Human Exposure and Dose Simulation (SHEDS)-Multimedia and Integrated Exposure Uptake and Biokinetic (IEUBK) models was developed using available data. This analysis for the U.S. population of young children probabilistically simulated multimedia exposures and estimated relative contributions of media to BLLs across all population percentiles for several age groups.
Modeled BLLs compared well with nationally representative BLLs (0-23% relative error). Analyses revealed relative importance of soil and dust ingestion exposure pathways and associated Pb intake rates; water ingestion was also a main pathway, especially for infants.
This methodology advances scientific understanding of the relationship between lead concentrations in drinking water and BLLs in children. It can guide national health-based benchmarks for lead and related community public health decisions. https://doi.org/10.1289/EHP1605.
饮用水及其他铅源是密歇根州弗林特市饮用水问题以及印第安纳州东芝加哥市土壤铅污染危机引发公众健康担忧的主题。2015年，美国环境保护局（EPA）的国家饮用水咨询委员会（NDWAC）建议基于儿童接触情况，为饮用水中的铅设定一个“基于健康的家庭行动水平”。
主要目标是开发一种耦合暴露剂量建模方法，该方法可用于确定何种饮用水铅浓度能使儿童血铅水平（BLLs）低于特定值，同时考虑来自水、土壤、灰尘、食物和空气的接触。相关目标包括使用实际血铅数据评估耦合模型估计值，量化各种媒介的相对贡献，并确定关键模型输入。
利用现有数据开发了一种使用EPA的随机人类暴露与剂量模拟（SHEDS）-多媒体模型和综合暴露吸收与生物动力学（IEUBK）模型的建模方法。针对美国幼儿群体的这项分析对多媒体暴露进行了概率模拟，并估计了不同年龄组所有人口百分位数中各媒介对BLLs的相对贡献。
模拟的BLLs与具有全国代表性的BLLs相比效果良好（相对误差为0 - 23%）。分析揭示了土壤和灰尘摄入暴露途径及相关铅摄入量的相对重要性；饮水摄入也是主要途径，尤其是对婴儿而言。
该方法推进了对饮用水中铅浓度与儿童BLLs之间关系的科学理解。它可指导基于健康的国家铅基准及相关社区公共卫生决策。https://doi.org/10.1289/EHP1605
