BACKGROUND: Drinking water is a lingering hazard in the effort to eliminate childhood exposure to lead (Pb), a neurotoxin that affects cognitive and behavioral development. This study characterized Pb in municipal drinking water at North Carolina, US, childcare centers. The study also demonstrates a scalable, citizen science-based drinking water testing strategy for Pb at childcare centers.
METHODS: Licensed childcare centers in four North Carolina counties were recruited. One administrator per center completed a survey and was trained to collect first-draw drinking water samples in their center. Samples were shipped with pre-paid labels for laboratory analysis using inductively coupled plasma mass spectrometry. Multilevel logistic regression and Bayesian network analysis were used to identify factors associated with a risk of exceeding the 1 μg/L American Academy of Pediatrics reference level and the US Environmental Protection Agency (US EPA) 15 μg/L treatment-based action level. Results were provided to centers along with risk mitigation recommendations.
RESULTS: Of 103 enrolled centers, 86 completed the study, submitting 1,266 drinking water samples in total. Approximately 77% of drinking water samples contained detectable Pb (≥0.1 μg/L), and 97% of centers had at least one drinking water sample with detectable Pb. More than 63% of centers had at least one drinking water sample with >1 μg/L Pb, and 17% of centers had at least one drinking water sample with Pb above 15 μg/L. There was high variability in Pb concentrations at water points within the same center.
DISCUSSION: This study demonstrated a high prevalence and variability of Pb in first-draw samples of drinking water at childcare centers in North Carolina, US. Results underscore the importance of testing for Pb at every tap used for drinking and cooking in childcare centers. The use of employees as citizen scientists is a feasible strategy to identify Pb in specific drinking water taps.