Lymphoma development among mice exposed to X-rays and pulsed magnetic fields

CBA mice were exposed to a total of 5.24 Gy X-rays (260 kV, 11 mA, 0.45 Gy/min), divided into four exposures, and to saw-tooth 15 microT (peak to peak) pulsed vertical 200 kHz magnetic fields for their life-time. In parallel, series with magnetic fields only or non-exposed animals were run. The animals were observed for their life-time. The frequency of lymphomas was 65.7% in the X-ray group and 71.4% in the groups exposed to both X-ray and magnetic field. Of the non-exposed control animals, and of the animals exposed to magnetic fields only 6.4 and 5.7% had lymphomas, respectively. There were no statistically significant differences between the magnetic field series and the corresponding controls for lymphomas. Blood cell counts and haemoglobin data did not show differences between the X-irradiated, and X-ray and magnetic field-exposed groups. Mononuclear cells and total leukocytes were elevated for pulsed magnetic fields-exposed animals compared with the non-exposed controls. This difference was due to two animals with extreme values. In the pulsed magnetic fields treated group there was a statistically significant increase of the carcass weight compared with the non-treated control group.