Measurements and modeling of lead reduction strategies

Abstract

Three 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.

Rapid and simple lead service line detection screening protocol using water sampling

“…LSLs can contribute as much as 50%-75% of the total lead at the tap after an extended stagnation time (Cartier et al, 2011;Lytle et al, 2019;Sandvig et al, 2008), and logically, bottle-fed infants will potentially have a very high relative exposure from drinking water used to make formula where LSLs are present (Stanek et al, 2020;Zartarian et al, 2017). LSL replacement remains the most effective long-term solution to eliminate likely the largest risk of lead exposure from drinking water (Cornwell et al, 2021;Environmental Protection Agency, 2021;Stanek et al, 2020). However, replacing the existing legacy of the estimated 6-10 million or more LSLs (Cornwell et al, 2016;e-CFR Electronic Code of Federal Regulations, 2019;Weston, 1990) is expected to come with significant expense over a long period of time.…”