Measurements and modeling of lead reduction strategies

Abstract

AbstractThree strategies for reducing lead in water and blood lead level (BLL) were evaluated. Approximately 2,500 lead samples from 112 homes were analyzed to estimate lead reduction from full lead service line replacement (FLSLR). Corrosion‐control changes were evaluated using data from more than 20,000 community water systems (CWSs). The reduction in first‐liter median lead for utilities changing corrosion‐control treatment (CCT) to drop the 90th percentile from 15 to 10 μg/L was 0.4 μg/L, while the reduction in lead for the highest 10% of the population in those communities was 3.7 μg/L. Lowering the goal to 5 μg/L resulted in the median and top 10% lead reducing by 0.4 and 4.5 μg/L, respectively, although more utilities and hence children are impacted by the lower goal. The median home had a first‐L and profile average lead reduction of about 2 μg/L following FLSLR. Ten percent of the homes saw a reduction in profile average lead of over 17 μg/L after FLSLR. These reductions in lead were converted to changes in BLL, including the percentage and total number of children with BLL values above 3.5 and 5 μg/dl. Those results show that the reduction in total number of children above these targets is noticeably higher for the 5 μg/L goal due to the difference in impacted population. LSL replacement provides the greatest reduction in number of children above these two candidate target values of BLL.Article Impact StatementThe largest reduction in BLL resulted from FLSLR. This is consistent with NDWAC report that FLSLR has a larger impact than improving CCT.