Rapid HPGe well detector gamma bioassay of 137Cs, 60Co, and 192Ir method.

CDC designed a rapid HPGe Bioassay Method for 137Cs, 60Co, and 192Ir that is suitable for a public health response to a radiological incident where people may ingest or inhale radionuclides. The method uses a short count time, small sample volume, and a large volume detector and well size. It measures a patient's urine sample collected post-incident. The levels of concern are directly related to the Clinical Decision Guide levels recommended in the National Council of Radiation Protection 161.

Evaluating the performance of the ORTEC® Detective™ for emergency urine bioassay.

The performance of the ORTEC(®) Detective™ as a field deployable tool for emergency urine bioassay of (137)Cs, (60)Co, (192)Ir, (169)Yb and (75)Se was evaluated against ANSI N13.30. The tested activity levels represent 10 % RL (reference level) and 1 % RL defined by [Li C., Vlahovich S., Dai X., Richardson R. B., Daka J. N. and Kramer G. H. Requirements for radiation emergency urine bioassay techniques for the public and first responders. Health Phys (in press, 99(5), 702-707 (2010)]. The tests were conducted for both single radionuclide and mixed radionuclides at two geometries, one conventional geometry (CG) and one improved geometry (IG) which improved the MDAs (minimum detectable amounts) by a factor of 1.6-2.7. The most challenging radionuclide was (169)Yb. The measurement of the mixture radionuclides for (169)Yb at the CG did not satisfy the ANSI N13.30 requirements even at 10 % RL. At 1 % RL, (169)Yb and (192)Ir were not detectable at either geometry, while the measurement of (60)Co in the mixed radionuclides satisfied the ANSI N13.30 requirements only at the IG.

Long-term clearance kinetics of inhaled ultrafine insoluble iridium particles from the rat lung, including transient translocation into secondary organs.

Recently it was speculated that ultrafine particles (UFP) may translocate from deposition sites in the lungs to systemic circulation and whether long-term clearance differs between ultrafine and micrometer-sized particles. We have studied lung retention and clearance kinetics in 12 healthy male adult WKY rats up to 6 mo after an inhalation of (192)Ir-radiolabeled, insoluble, ultrafine 15- to 20-nm iridium particles. Whole-body retention was followed by external gamma counting, and particle clearance kinetics were determined by excretion radioanalysis. Four rats each were sacrificed after 3 wk and 2 and 6 mo; all organs as well as tissues and the carcass were radioanalyzed to balance the entire deposited radioactivity of the particles. The most prominent fraction was retained in the lungs at each time point of sacrifice (26%, 15%, 6%, respectively), and clearance out of the body was solely via excretion. Extrapulmonary particle uptake did not continue to increase but decreased with time in liver, spleen, heart, and brain when compared to previous data obtained during the first 7 days after inhalation (Kreyling et al., 2002). UFP long-term lung retention derived from whole-body measurements was comparable to previously reported data using insoluble micrometer-sized particles (Bellmann et al., 1994; Lehnert et al., 1989). In addition, differential analysis including daily excretion data revealed a pattern of fractional particle clearance rate of the ultrafine iridium particles similar to that of micrometer-sized particles reported by Snipes et al. (1983) and Bailey et al. (1985).

192IrCl acid skin burn: case report and review of the literature.

A worker was contaminated following a chemical explosion that splashed an HNO3 radioactive solution containing approximately 180 MBq (5 mCi) 192Ir onto the left side of his face. Initial efforts reduced the contamination at least fivefold. Removal of a patch of contaminated hair was necessary. Most of the contamination was fixed to the skin; only a small amount of contamination was absorbed.