PT - JOURNAL ARTICLE AU - Hackett, Michael T. AU - Collins, Judith A. AU - Wierzbinski, Rebecca S. TI - <sup>133</sup>Xe Contamination Found in Internal Bacteria Filter of Xenon Ventilation System DP - 2003 Sep 01 TA - Journal of Nuclear Medicine Technology PG - 170--172 VI - 31 IP - 3 4099 - http://tech.snmjournals.org/content/31/3/170.short 4100 - http://tech.snmjournals.org/content/31/3/170.full SO - J. Nucl. Med. Technol.2003 Sep 01; 31 AB - Objective: We report on 133Xe contamination found in the reusable internal bacteria filter of our xenon ventilation system. Methods: Internal bacteria filters (n = 6) were evaluated after approximately 1 mo of normal use. The ventilation system was evacuated twice to eliminate 133Xe in the system before removal of the filter. Upon removal, the filter was monitored using a survey meter with an energy-compensated probe and was imaged on a scintillation camera. The filter was monitored and imaged over several days and was stored in a fume hood. Results: Estimated 133Xe activity in each filter immediately after removal ranged from 132 to 2,035 kBq (3.6–55.0 μCi), based on imaging. Initial surface radiation levels ranged from 0.4 to 4.5 μSv/h (0.04–0.45 mrem/h). The 133Xe activity did not readily leave the filter over time (i.e., time to reach half the counts of the initial decay-corrected image ranged from &lt;6 to &gt;72 h). The majority of the image counts (~70%) were seen in 2 distinctive areas in the filter. They corresponded to sites where the manufacturer used polyurethane adhesive to attach the fiberglass filter medium to the filter housing. Conclusion: 133Xe contamination within the reusable internal bacteria filter of our ventilation system was easily detected by a survey meter and imaging. Although initial activities and surface radiation levels were low, radiation safety practices would dictate that a 133Xe-contaminated bacteria filter be stored preferably in a fume hood until it cannot be distinguished from background before autoclaving or disposal.