RESUMO
Immediate and complete decontamination procedures are essential to restore the functionality, precision, accuracy, and safety of tests done within the nuclear medicine facility. Decontamination is a simple procedure that, if performed correctly, effectively reduces exposure brought about by spills. The determination of a suitable radiodecontaminant may be beneficial in decontaminating patient beds, collimators, probes, and machines. Methods: Two surface types (i.e., stainless steel and vinyl) were contaminated with a predetermined activity of 99mTcO4 and 131I. After air drying, static images of the contaminated surfaces were obtained using a γ-camera to determine the activity counts on each surface before and after decontamination procedures. Different decontaminant contact times (i.e., 5, 10, and 15 min) were used for each decontaminant (i.e., ionized water, 10% bleach, detergent solution, a negative control [no treatment], and a positive control [a commercial radiodecontaminant]). Differences between the effectiveness of ionized water and the other decontaminants against 99mTcO4 and 131I at different contact times were measured, and the mean percentage activity removed (%AR) was compared using 2-way ANOVA at the 0.05 level of significance. Results: 99mTcO4 and 131I contaminants had %ARs of greater than 80% after 5 min of contact time for ionized water and the other decontaminants. At 15 min contact time, ionized water was not as effective as the other decontaminating agents for 131I on vinyl surfaces. There was no significant interaction between the effects of the decontaminants (%AR) and the contact times with stainless steel and vinyl for either 99mTcO4 or 131I. Conclusion: For 99mTcO4 and 131I on stainless steel surfaces, ionized water is an effective decontaminant at contact times of 5, 10, and 15 min. For 99mTcO4 on vinyl surfaces, ionized water is also an effective decontaminant at contact times of 5, 10, and 15 min. For 131I on vinyl surfaces, ionized water is as effective as 10% bleach, detergent solution, and a commercial radiodecontaminant at contact times of 5 and 10 min.