Towards low-cost lead screening with transmission XRF

Human exposure to lead (Pb) is a global health concern, yet existing technologies for detecting lead in our environment remain prohibitively expensive for widespread deployment. Here we present a new theoretical concept towards lead screening using X-ray fluorescence (XRF) in an unconventional geometry we coin transmission XRF in which the sample is placed between the source and detector. For cost reduction, we then show that 241 Am found in ionizing smoke detectors is spectrally suitable for Pb L-shell XRF generation and can thus replace X-ray tubes used in conventional XRF devices. Exploring soil screening as the first application, we demonstrate with Monte Carlo simulations that a configuration with 7 × 241 Am sources and a standard silicon drift detector could enable screening-relevant detection limits (100 ppm Pb) in soil within practical measurement times (<30 min). We believe this concept opens a route toward low-cost and scalable XRF instrumentation for democratizing lead screening across a wide range of samples.