Acute And Chronic Health Effects From Lead In Drinking Water Of Schools And Day Care Facilities: Detection, Bio-Availability, And Predicted Impacts On Blood Lead

学校和日托机构饮用水中的铅对健康的急性和慢性影响：检测、生物利用度以及对血铅的预测影响

• 批准号: 0933246
• 负责人: Marc Edwards
• 金额: $ 36.99万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0933246&HistoricalAwards=false
• 关键词: Acute; Chronic; Health; Effects; Lead

0933246 EdwardsThe United States currently has a voluntary program to identify, detect and mitigate problems with lead in drinking water of schools and day care centers. Although the conventional wisdom is that lead in school water poses little health risk, substantive gaps in understanding may have caused the magnitude of this problem to be underestimated. The combination of "worst case" plumbing configurations and water flow patterns, and susceptible populations of very young children, makes a detailed evaluation of this issue desirable. Three phases of research are directed at resolving the most important issues. The first examines key aspects of lead occurrence in potable water of schools using intensive sampling events designed to statistically characterize the natural variability of lead in water. A similar analysis will be conducted for selected "problem" taps that are known to dispense hazardous waste levels of lead with at least some frequency. The level of lead in hot water will also be systematically tested for the first time. Sampling protocols are designed to ensure that none of the lead in water is "missed", as often occurs when using conventional lead in water analytical procedures and guidance. The occurrence of high lead in water will then be forensically linked to specific plumbing sources using an array of analytical techniques. The second phase of work systematically evaluates the bioavailability of the lead. It has been speculated that the particulate lead in water is not bioavailable and poses little health risk, but on the other hand several recent cases of lead poisoning for children were unambiguously tied to the presence of small particles of lead solder in the water. Samples of particulate lead from water of schools will be exposed to a range of representative simulated gastric acids, churn conditions, and stomach retention times. Lead dissolution will be tracked in samples as a function of particle size and type of lead particle present. Tests will also be conducted to examine partitioning of particulate lead in water to pasta during cooking, and the role of trace reducing agents in gastric acid in rendering particulate lead more or less bioavailable. This fundamental research has not been previously conducted for lead particulates derived from real drinking waters. Finally, bio-kinetic models will be utilized that incorporate results of the first two phases of research, in order to evaluate a range of realistic exposure scenarios by which children might be exposed to lead in water while in schools. Prior modeling efforts were significantly biased towards underestimating the elevation in blood lead that might result from exposure to lead contaminated drinking water. This modeling work will be the first to: 1) consider acute as well as chronic health risks, 2) evaluate the potential hazard that arises from use of hot water for instant infant formula, soups, and tea (it is suspected that there is often much more lead in hot water than cold water), and 3) determine the possible contribution of lead in foods cooked in contaminated water. This research work is a collaborative effort between Virginia Tech, the Children?s National Medical Center (CNMC), the Alliance for Healthy Homes, Parents for Non-toxic Alternatives, and a network of concerned parents and high school students/teachers. Results will be used in considering the protectiveness of existing approaches that are used to control and mitigate lead hazards in potable water of schools and homes. Our unfunded preliminary efforts have already had a significant effect, as evidenced by tougher standards in the State of Washington and in Canada, and through a re-evaluation of effects of high lead in water on blood lead of children in Washington D.C. from 2001-2007. These initial successes, interdisciplinary approach, and clear public health implications support the need for the research.

0933246美国目前有一项自愿计划，以识别，发现和减轻学校和日托中心饮用水中的问题。尽管传统的观点是学校水中的铅构成很少的健康风险，但理解的实质性差距可能导致该问题的幅度被低估了。 “最坏情况”的管道构型和水流模式以及非常年幼的孩子的易感人群的结合使人们对此问题进行了详细的评估。研究的三个阶段旨在解决最重要的问题。第一个检查了学校饮用水中铅出现的关键方面，使用旨在从统计上表征水中铅自然变异的密集抽样事件。对于所选的“问题”水龙头，将进行类似的分析，该抽头已知会以至少一定的频率分配危险废物水平。热水中的铅含量也将首次系统地测试。采样方案旨在确保在水分析程序和指导中使用常规铅时通常会发生水中的铅。然后，使用一系列分析技术将高铅在水中的出现将与特定的管道源相连。工作的第二阶段系统地评估了铅的生物利用度。据推测，水中的颗粒物铅不是生物利用的，并且很少构成健康风险，但另一方面，最近有几例儿童铅中毒的病例与水中的小铅焊料存在明确关系。从学校水中的颗粒铅样品将暴露于一系列代表性的模拟胃酸，流失条件和胃部保留时间。铅溶解将在样品中跟踪，这是粒径和存在的铅颗粒类型的函数。还将进行测试，以检查烹饪过程中水中颗粒铅的颗粒铅的分配，以及痕量还原剂在胃酸中的作用在使颗粒物铅铅铅铅中或多或少可生物利用中的作用。这项基本研究以前尚未针对来自实际饮酒水的铅颗粒。最后，将利用生物运动模型结合了研究的前两个阶段的结果，以评估一系列现实的暴露情况，在学校中，儿童可能会在水中暴露在水中。先前的建模工作明显偏向于低估血液铅的升高，这可能是由于暴露于铅受污染的饮用水而导致的。这项建模工作将是：1）考虑急性和慢性健康风险，2）评估由于将热水用于即时婴儿配方奶粉，汤和茶所带来的潜在危害（怀疑在热水中通常比冷水中的铅更多的铅），3）确定铅在污染水中煮熟的食物可能造成铅的可能性。这项研究工作是弗吉尼亚理工学院，儿童国家医疗中心（CNMC），健康家庭联盟，无毒替代方案的父母与有关父母和高中生/老师的网络之间的合作努力。结果将用于考虑用于控制和减轻学校和家庭饮用水中的铅危害的现有方法的保护。我们无资金的初步努力已经产生了重大影响，这是由华盛顿州和加拿大的更坚强的标准所证明的，以及通过对2001年至2007年华盛顿特区儿童血统的高铅对水对血液铅的影响的重新评估。这些最初的成功，跨学科的方法和明确的公共卫生影响支持了对研究的需求。