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

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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.