Water lead exposure risk in Flint, Michigan after switchback in water source: Implications for lead service line replacement policy.
Water lead exposure risk in Flint, Michigan after switchback in water source: Implications for lead service line replacement policy.
复制标题
密歇根州弗林特水源折线后的水铅暴露风险：对铅服务管线更换政策的影响。
DOI：
10.1016/j.envres.2019.108928
复制
发表时间：
2020
影响因子：
8.3
通讯作者：
Keyes,Christopher
中科院分区：
文献类型：
--
作者：
Zahran,Sammy;Mushinski,David;McElmurry,ShawnP;Keyes,Christopher
2016 年 2 月，密歇根州弗林特市启动了 FAST 启动计划，旨在通过更换全市的铅钢和镀锌钢服务线，“让弗林特市取得领先地位”。预计将有 29,100 个包裹进行服务线更换 (SLR)，预计成本为 1.72 亿美元。 SLR 的铅暴露效益通过分析 2016 年 2 月 16 日至 2017 年 7 月 21 日期间对弗林特数百个重复采样的家庭的 Sentinel 数据进行评估，比较有和没有铅服务线的家庭的水铅 (WL)。从有铅服务线路的家庭中采集的样本比没有铅服务线路的家庭更有可能超过指定的 WL 阈值。其次，无论服务线材料类型如何，随着弗林特之字形转向底特律供水和污水处理部门提供水的时间的推移，样本家庭的 WL 显着降低。第三，超过 WL > 15 μg/L 的风险与服务线材料类型不相关。这些结果对于样本限制、时期分层、时间操作、参考组定义和统计建模程序来说是稳健的。关于 SLR 相对于最佳腐蚀控制技术能带来什么好处的问题，我们模拟了弗林特儿童从弗林特之字线改用底特律水起第 16 周和第 90 周的年龄特定铅吸收量（μg/天）和血铅水平（μg/dL）。水源折返后第 90 周，有铅供水管的家庭中的儿童消耗的铅水量比第 16 周减少了 93%。 SLR 的铅暴露效益随着时间的推移而下降，不同服务系列的家庭之间的铅摄入量差异不大。根据结果，讨论了弗林特和全国范围内的政策考虑。
In February of 2016, the City of Flint, Michigan commenced the FAST start initiative with the aim “to get the lead out of Flint” by replacing lead and galvanized steel service lines throughout the city. An estimated 29,100 parcels are scheduled for service line replacement (SLR) at an expected cost of $172 million. Thelead exposure benefitsof SLR are evaluated by analyzing Sentinel data on hundreds of repeatedly sampled homes in Flint from February 16, 2016 to July 21, 2017, comparing water lead (WL) in homes with and without lead service lines. Samples taken from homes with lead service lines were significantly more likely to exceed specified thresholds of WL than homes without lead service lines. Second, regardless of service line material type, sampled homes experienced significant reductions in WL with elapsed time from Flint’s switchback to water provided by the Detroit Water and Sewage Department. Third, the risk of exceedance of WL > 15 μg/L was uncorrelated with service line material type. These results are robust to sample restrictions, period stratification, time operations, reference group definitions, and statistical modeling procedures. On the question of what is gained from SLR over optimal corrosion control techniques, we simulated age-specific lead uptake (μg/day) and blood lead levels (μg/dL) for children in Flint at 16 and 90 weeks of elapsed time from Flint’s switchback to Detroit water. At 90 weeks from the switchback in water source, the quantity of water lead consumed by children in homes with lead service lines decreased 93%, as compared to 16 weeks. Lead exposure benefits of SLR have declined in time, with modest differences in lead uptake across homes with different service lines. In light of results, policy considerations for Flint and nationwide are discussed.