Drinking water is an important source of lead exposure, and definitively characterizing the sources of lead in drinking water, particularly in large institutional settings, can be time-consuming and costly. This study examined lead concentrations in drinking water at a large university, focusing on variability in first-draw samples and variability with dispensed volume. Over 350 sources were sampled twice by independent groups, and while 78% of these samples were within 2.5 μg/L, almost 10% differed by >10 μg/L. In both sampling events, approximately 50% of sources had lead concentrations >1 μg/L, 6% were >15 μg/L, and 30% were between 1 and 15 μg/L. The highest lead concentration detected was 400 μg/L, with five sources >100 μg/L. Nine sources were sampled more intensively and six had first-draw sample ranges >5 μg/L. Lead concentration versus dispensed volume profiles indicated that while most sources had decreasing lead concentrations after the first draw, others had maximum lead concentrations at higher dispensed volumes. The variability observed suggests that assessments using only one or two samples per source may not identify all sources with elevated lead concentrations, and management strategies should account for this possibility.

中文翻译：

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在大型学术机构中评估铅污染的饮用水：一个案例研究。

饮用水是铅暴露的重要来源，而且要明确表征饮用水中铅的来源，尤其是在大型机构环境中，可能既费时又费钱。这项研究检查了一所大型大学的饮用水中铅的浓度，重点研究了第一批抽取样品的变异性和分配量的变异性。独立小组对超过350种来源进行了两次采样，尽管其中78％的样品浓度在2.5μg/ L以内，但几乎10％的样品相差> 10μg/ L。在这两个采样事件中，大约50％的来源的铅浓度> 1μg/ L，6％的铅浓度> 15μg/ L，30％的铅浓度在1至15μg/ L之间。检测到的最高铅浓度为400μg/ L，其中五个来源> 100μg/ L。对9个来源进行了更密集的采样，其中6个样本的首次抽取样本范围> 5μg/ L。铅浓度与分配体积的关系曲线表明，虽然大多数来源在第一次抽取后的铅浓度降低，但其他来源在较高的分配体积时具有最大铅浓度。观察到的变异性表明，每个来源仅使用一个或两个样本进行的评估可能无法识别出铅浓度升高的所有来源，因此管理策略应说明这种可能性。