Childhood Lead-Exposure Prevention Through Predictive Mapping of At-Risk Housing Nationwide: A Free, Public-Data Screening Map Checked Against Measured Blood Lead in 11 States.

Childhood lead exposure causes irreversible neurodevelopmental harm, and no safe blood lead level in children has been identified. Measured childhood blood lead is collected unevenly across the United States, and many areas publish no neighborhood-level surveillance, so the children at highest risk are often the hardest to find by measurement. Building on the U.S. Environmental Protection Agency finding that housing age and poverty predict where childhood lead exposure concentrates, we computed a lead-exposure risk score for all 83,388 U.S. census tracts and 3,222 counties from public American Community Survey housing-age and poverty data, and tested it against measured childhood blood lead in 11 states by Spearman rank correlation. On surveillance the source study never used, predicted risk tracked measured elevated blood lead at rho = 0.64 across Wisconsin's 1,308 census tracts, with five independent county-scale states ranging from 0.48 to 0.77 and three further independent tract states (Massachusetts, Rhode Island, Minnesota) agreeing. A flexible model on the same public inputs explains only about half the tract-level variance, so housing age and poverty leave most of the variation unexplained, and the map is a screening signal rather than a diagnosis. Every validation state is an older-housing Northeast, Midwest, or Great Plains jurisdiction, so the low-risk predictions for the newer-built West and Sun Belt remain an untested extrapolation. Reproducible from public data and free to use, the map ranks where confirmatory testing should go first, including in states that publish no surveillance of their own.