A magnetic field exposure facility for evaluation of animal carcinogenicity

Several animal studies have been carried out at the Institut Armand Frappie r (IAF) to determine whether chronic exposure to 60 Hz linearly polarized s inusoidal magnetic fields might increase the risk of cancer development of female Fisher rats. The magnetic field exposure facility was developed to m eet the requirements of the study protocol for chronic exposure of large nu mber of animals to field intensities of sham < 0.2 mu T, 2 mu T, 20 mu T, 2 00 mu T, and 2000 mu T. At each exposure level, including sham, the animals are distributed in a group of four exposure units. Each exposure unit cont ains two exposure volumes having uniform distribution of magnetic fields fo r the animals, while the magnetic field external to the unit falls off rapi dly due to the "figure-eight" coil topography used. A program of "shake dow n" tests, followed by verification and calibration of the exposure facility , was carried out prior to starting the animal experiments. Continuous moni toring of the magnetic field and other environmental parameters was an impo rtant part in the overall quality assurance program adopted. (C) 2000 Wiley -Liss, Inc.