[Microorganisms in the open air during the period of a winter-half-year (author's transl)]

During the winter-half-year 1976/77 the concentrations of airborne microorganisms in the open air were measured in Bonn and at a place in the Sauerland. Simultaneously the data of wind direction, wind speed, atmospheric rel. humidity, temperature, intensity of solar radiation were registered. It can be shown, that the denominated parameters are influencing the content of microorganisms of the air in different proportions.