Prediction of children's blood lead levels from exposure to lead in schools' drinkingwater-A case study in Tennessee, USA

Abstract

Lead (Pb) exposure can delay children's mental development and cause behavioral disorders and IQ deficits. With children spending a significant portion of their time at schools, it is critical to investigate the lead concentration in schools' drinking water to prevent children's exposure. The objectives of this work were to predict students' geometric mean (GM) blood lead levels (BLLs), the fractions of at-risk students (those with BLLs > 5 g/dL), and the total number of at-risk students in one Tennessee school district. School drinking water lead concentration data collected in 2019 were input into the Integrated Exposure Uptake Biokinetic (IEUBK) model and the Bowers' model to predict BLLs for elementary school students and secondary school students, respectively. Sensitivity analyses were conducted for both models. Drinking water concentrations were qualitatively compared with data collected in 2017. Two scenarios were evaluated for each model to provide upper and median estimates. The weighted GM BLL upper and median estimates for elementary school students were 2.35 g/dL and 0.99 g/dL, respectively. This equated to an upper estimate of 1300 elementary school students (5.8%) and a median estimate of 140 elementary school students (0.6%) being at risk of elevated BLLs. Similarly, the weighted GM BLL upper and median estimates for secondary school students were 2.99 g/dL and 1.53 g/dL, respectively, and equated to an upper estimate of 6900 secondary school students (13.6%) and a median estimate of 300 secondary school students (0.6%) being at risk of elevated BLLs. Drinking water remediation efforts are recommended for schools exhibiting water lead concentrations greater than 15 g/L. Site-specific soil lead concentration data are recommended since the IEUBK was deemed sensitive to soil lead concentrations. For this reason, soil lead remediation may have a greater impact on lowering children's BLLs than drinking water lead remediation. Remediation efforts are especially vital at elementary schools to reduce the population's baseline BLL and thus the BLL projected by Bowers' model.