METHODS FOR MEASURING THE ACTIVITY SIZE DISTRIBUTION FOR ULTRAFINE PARTICLES

THE SCIENTIFIC CONSENSUS IS THAT THE UNATTACHED FRACTION OF RADON PROGENY POSES A MUCH GREATER HEALTH RISK THAN THE ATTACHED FRACTION. DEVELOPMENT OF A COMMERCIAL DEVICE TO DETERMINE THE CONCENTRATIONS OF ATTACHED AND UNATTACHED FRACTIONS IS ESSENTIAL TO COUNT DECAY PRODUCTS AND ASSESS HEALTH EFFECTS ACCURATELY. PHASE I INVOLVES TESTING AND OPTIMIZATION OF IMPROVED INSTRUMENTATION TO DETERMINE CONCENTRATION OF RADON PROGENY IN THE AIR. THE DEVICE WILL DIFFERENTIATE BETWEEN THE ATTACHED AND UNATTACHED FRACTIONS OF RADON PROGENY. DETAILS ON THE ACTIVITY SIZE DISTRIBUTIONOF PARTICLES LESS THAN 10 NM CAN BE PROVIDED BY FURTHER ANALYSIS OF THE DETECTION MATERIAL. BASED UPON PRELIMINARY RESULTS, THE DETECTOR IS VERSATILE ENOUGH TO DETERMINE THE EQUILIBRIUM FACTOR AND THE UNATTACHED FRACTION. DETECTOR CAPABILITIES WILL BE EVALUATED IN A VARIETY OF CONTROLLED AEROSOL ENVIRONMENTS. A SPECIFIC EVALUATION WILL BE DONE ONTHE BINDING POTENTIAL OF TOBACCO SMOKE OVER A WIDE RANGE OF AEROSOL ENVIRONMENTS. RESEARCH SUGGESTS THAT BY CHANGING THE CONFIGURATION AND DETECTION MATERIALS, SENSITIVITY CAN BE ALTERED TO VARY RUN TIMES FROM THE SHORT TERM (3 TO 5 DAYS) TO THE LONG TERM (3 TO 6 MONTHS). THE PROTOTYPES CAN BE MODIFIED TO CONVERT THEM INTO INEXPENSIVE MAIL-IN DEVICES. THIS ACCESSIBILITY BY THE GENERAL POPULATION WILL IN TURN PROVIDE MORE ACCURATE ESTIMATES OF DOSE VERSUS EXPOSURE UNDER A VARIETY OF ATMOSOPHERIC CONDITIONS. IMPROVED ESTIMATES OF DOSE WILL REDUCE THE UNCERTAINTY IN CURRENT NATIONAL LUNG RISK PROJECTIONS.