IMPROVED TECHNOLOGY FOR MEASURING LEAD DETECTION IN LEAD-BASED PAINT (PROPOSAL II)

LEAD IS A HIGHLY TOXIC SUBSTANCE, CAUSING SERIOUS HEALTH PROBLEMS, PARTICULARLY IN CHILDREN. THE EPA AND HUD CONSIDER LEAD PAINT TO BE A PRIMARY SOURCE OF LEAD POISONING. COMMERCIAL PAINT NO LONGER CONTAINS LEAD AND GOVERNMENT AGENCIES HAVE CALLED FOR ITS REMOVAL FROM OLDER HOMES. ONE SIGNIFICANT PROBLEM IS THE LACK OF RAPID, INEXPENIVE, RELIABLE METHODS FOR MEASURING LEVELS OF LEAD IN CONCENTRATIONS AS LOW AS 1 MG/CM2. NITON CORPORATION PROPOSES AN INEXPENSIVE PORTABLE X-RAY FLOURESCENCE (XRF) DETECTOR OF LEAD PAINT BASED ON MEASURING THE L X-RAY LINES OF LEAD RATHER THAT THE K X-RAY LINES. CONTRARY TO COMMON WISDOM AND LITERATURE, THEY FEEL THAT THIS PROPERLY DESIGNED DETECTOR COULD MEASURE CONCENTRATIONS OF LEAD BELOW 1 MG/CM2, UNDER MANY LAYERS OF LEAD-FREE PAINT. THE L X-RAY DETECTOR IS VERY SENSITIVE TO SO-CALLED MATRIX EFFECTS, BUT ANALYSIS INDICATES THAT THESE COULD BE SUCCESSFULLY DEALT WITH IF ACCOUNT IS TAKEN OF THE FULL XRF ENERGY SPECTRUM OF GOOD ENERGY RESOLUTION. IN PHASE I, THEY WOULD DEVELOP THE FIRST STAGE OF THE DETECTOR AND STUDY THE MATRIX EFFECTS. IN PHASE II, THEY PLAN TO CONSTRUCT A PROTOTYPE XRF DETECTOR AND TEST IT.