Medical radionuclide impurities in wastewater

Dept. of Nuclear Engineering and Radiation Health Physics, Oregon State University, 132 Radiation Center, Corvallis, OR 97331

Abstract

NCRP report No.160 states medical exposures constituted nearly half of the total radiation exposure of the US population from all sources in 2006 [1]. Part of this increase in exposure is due to the rise in nuclear medicine procedures. With this observed growth in medical radionuclide usage there is an increase in the activity being released into wastewater after medical procedures. Often medical radionuclides are not 100% radionuclide pure, but meet a certain standard of purity. Of particular interest are the longer lived impurities associated with these medical radionuclides. The longer lived impurities have a higher chance of reaching the environment. The goal of this study is to identify radionuclide impurities associated with some of the more common radiopharmaceuticals Tc-99m and I-131, locate and quantify the levels of these impurities in municipal wastewater, and make a determination as to the potential long-term impact.