Modeled Impacts of Drinking Water Pb Reduction Scenarios on Children’s Exposures and Blood Lead Levels
In recent years, environmental lead (Pb) exposure through drinking water has resulted in community public health concerns, particularly in children. To understand potential impacts on childhood blood Pb levels (BLLs) from various drinking water Pb reduction scenarios (i.e. lead service line removal and corrosion control treatment), EPA’s coupled Stochastic Human Exposure and Dose Simulation (SHEDS)-Multimedia/Integrated Exposure Uptake and Biokinetic (IEUBK) modeling system was applied for national-scale analyses. Two separate approaches were used to estimate drinking water Pb concentrations for model inputs: one utilized sequential sampling data from field studies; the other a “bounding” dataset spanning a range of realistic mean water Pb concentrations and variabilities. For both approaches across the scenarios considered, average modeled contribution to BLLs from ingestion of residential drinking water ranged from ~10-80%, with the highest for formula-fed infants (age 0 to <1 year). Relative contributions to BLLs from various ingestion and inhalation exposure pathways were highly sensitive to drinking water Pb concentration inputs. Despite uncertainties in current measurements, the results for both approaches show that drinking water can be an important exposure pathway for total Pb exposure in children and infants. Significant decreases in children’s BLLs can result from Pb in drinking water reduction actions.