Radiofrequency dosimetry for the Ferris-wheel mouse exposure system.
Numerical and experimental methods were employed to assess the individual and collective dosimetry of mice used in a bioassay on the exposure to pulsed radiofrequency energy at 900 MHz in the Ferris-wheel exposure system (Utteridge et al., Radiat. Res. 158, 357-364, 2002). Twin-well calorimetry was employed to measure the whole-body specific absorption rate (SAR) of mice for three body masses (23 g, 32 g and 36 g) to determine the lifetime exposure history of the mice used in the bioassay. Calorimetric measurements showed about 95% exposure efficiency and lifetime average whole-body SARs of 0.21, 0.86, 1.7 and 3.4 W kg(-1) for the four exposure groups. A larger statistical variation in SAR was observed in the smallest mice because they had the largest variation in posture inside the plastic restrainers. Infrared thermography provided SAR distributions over the sagittal plane of mouse cadavers. Thermograms typically showed SAR peaks in the abdomen, neck and head. The peak local SAR at these locations, determined by thermometric measurements, showed peak-to-average SAR ratios below 6:1, with typical values around 3:1. Results indicate that the Ferris wheel fulfills the requirement of providing a robust exposure setup, allowing uniform collective lifetime exposure of mice.
Faraone
Antonio
A
Corporate EME Research Laboratory, Motorola Labs, Fort Lauderdale, Florida 33322, USA. antonio.faraone@motorola.com
Luengas
Wilson
W
Chebrolu
Subbarao
S
Ballen
Maurice
M
Bit-Babik
Giorgi
G
Gessner
Andrew V
AV
Kanda
Michael Y
MY
Babij
Tadeusz
T
Swicord
Mays L
ML
Chou
Chung-Kwang
CK
D000818:Animals; D001822:Body Burden; D002102:Cadaver; D004867:Equipment Design; D019544:Equipment Failure Analysis; D051379:Mice; D009928:Organ Specificity; D011829:Radiation Dosage; D011846:Radio Waves; D011874:Radiometry / Q000379:methods; D014915:Whole-Body Counting / Q000379:methods*; D014916:Whole-Body Irradiation / Q000295:instrumentation* / Q000379:methods*