TY - JOUR AU - Lev S Ruzer AU - Richard G Sextro BT - Radiation Protection Dosimetry LA - eng PY - 1997 SP - 135 EP - 140 T2 - Radiation Protection Dosimetry TI - Assessment of Very Low Aerosol Concentrations by Measuring the Unattached Fraction of 218Po VL - 71 ER -