For a long time it has been known that weather changes correlate with the incidence of acute diseases, symptoms like headaches, aching of surgery scarves, changes in blood pressure levels and many other indicators of health effects. It is very important that "weather sensitivity" symptoms also occur in people staying indoors. Consequently, the causal factors have to be physical agents reaching into enclosed spaces. Some of the parameters of physical environment fulfilling this presupposition are air pressure and its changes (Richner, 1978) and also oscillations of natural magnetic field (MFO). OAP is a natural noise of the atmosphere originating from very diverse sources. OAP intensity and frequency spectrum are very changeable. One of the main causes for the generation of OAP in disturbed areas of the atmosphere is turbulence of atmospheric flows. The frequency spectrum of turbulent noise is rather wide. It covers the whole sonic and infrasonic frequency range with highest intensities in the range of very low frequencies between 0.001 to 1 Hz. Turbulent OAP increase their intensity near obstacles and can reach hundreds of pascals during the stormy weather.

Recently physiological effects of artificial OAP modelling natural pressure fluctuations in the range of 0.011- 0.17 Hz were found in a group of volunteers (Delyukov, Gorgo, Didyk, Miroshnik et al.,1999;2000;2001;2002). Optimally chosen periodic OAP improved mental efficiency.

Similarly to atmospheric pressure, natural magnetic field also shows fluctuations. First of all, they depend on the “cosmic weather”, which includes the state of processes in the magnetosphere of the Earth and depends on solar activity. Besides, local electromagnetic field is sensitive to meteorological processes. The total amplitude of the natural MFO usually does not exceed 0,5 to 1 µT. These fluctuations are characterised by a complex spectrum in a wide range of frequencies. There exists an artificial component of the fluctuations of local magnetic field, created by technical devices. Artificial MFO at extremely low frequencies are considerably stronger than natural ones. Components with frequencies of 50 or 60 Hz and their harmonics predominate in their spectrum.

Natural and artificial MFO also can induce biological effects. According to a series of pilot studies, exposure to artificial MFO caused changes in physiological parameters of nervous, cardiovascular, endocrine and immune systems in human and in animals, which however did not exceed normal physiological ranges. Negative effects could be observed after a long-term magnetic field exposure. The type of the organismic response to MFO depends on the specific and non-specific adaptive reaction developing in the organism.