Evaluation of surface lead migration in pre-1950 homes: an on-site hand-held X-ray fluorescence spectroscopy study

Lead-paint concentration on specific surfaces (walls, floors, windowsills, etc.) in pre-1950 homes was measured using a hand-held X-ray fluorescence (XRF) spectroscope. Surface lead was examined concomitantly using wipe sampling and XRF Lead was detected in all 147 samples via XRF; and of these, 29 ( 20%) revealed surface lead contamination via wipe sampling. Seventeen of the positive wipe samples were collected from surfaces with clear visible defects, while 12 samples were collected from surfaces with no visible defects. Curve fitting of surface to lead-paint concentrations generated empirical relationships that described the migration of lead from inner layers at locations with and without visible defects. Curve fitting indicated that lead migration was power-law dependent when surface defects were present and linear when no defects were visible. These correlations may assist surveyors in predicting lead migration to the surface from lead-paint concentration measured with a hand-held XRF instrument.