Many of those tests are actually more likely to generate false positives than false negatives; I had our home tested by a professional with XRF gear, and his te

Many of those tests are actually more likely to generate false positives than false negatives; I had our home tested by a professional with XRF gear, and his tests indicated much lower levels of lead (late Victorian house, so we knew we had some) than the swab tests suggested. The main problem I see with this concept is that lead levels vary throughout living spaces, so you would need multiple samples. I'd think multiple, labeled, swab cloths would be more effective from a testing perspective.