title: The respiratory response to microwaves.
abstract: Male mice were irradiated with microwaves of 2450 MHz at a power intensity of 1, 10, and 100 mW/cm2 and a dose of 300 mW.min/cm2. An intensity of 100 mW/cm2 for 3 min causes thermal effects. The rectal temperature increased 2 degrees C, and the respiratory minute volume decreased during the first 2 min. After that, it increased rapidly and fluctuated until the irradiation was finished, when the minute volume decreased to a value lower than normal. A new method has been used for studying the effects on the nervous system with the help of tone pulses and the respiratory minute volume, an acoustic reaction. This reaction is affected at the very moment the irradiation starts and remains for some minutes after irradiation is finished. During an irradiation of 10 mW/cm2 in 30 min, both the minute volume and the acoustic reaction are decreased. The rectal temperature does not change. 1mW/cm2 during 300 min does not change the minute volume nor the rectal temperature but decreases the acoustic reaction 4 and 5 h after irradiation has started. In the present experiments, it is possible to evaluate the influence of heat and the heat regulation with the help of the respiratory minute volume and rectal temperature. The effects on the conditioned acoustic reaction indicate that the nervous system is involved independently of the created heat and the thermal regulatory processes during and after irradiation with microwaves of 2450 MHz and at intensities of 1, 10, and 100 mW/cm2.
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001833:Body Temperature Regulation / Q000528:radiation effects; D008176:Lung Volume Measurements; D008297:Male; D051379:Mice; D008872:Microwaves / Q000009:adverse effects*; D009420:Nervous System / Q000528:radiation effects; D012119:Respiration / Q000528:radiation effects*; D012449:Safety