Influence of sampling conditions on the height of emission factors for airborne micro-organisms from livestock production

Emission factors often are needed as an input parameter in dispersion models for the prediction of immissions in the surroundings of animal housings. Some of the published emission factors for airborne micro-organisms differ considerably for the same animal species and management type. This is due to different sampling conditions and methods for the determination of the micro-organism concentration which were used for the calculation of these factors. There is a lack of valid data even for the classical management types and there are no data available for naturally ventilated animal houses and outdoor husbandry system. In addition most of the emission factors refer only to microbiological sum parameters and not to parameters which are specific for animal housings. Therefore, for the determination of representative emission factors further measurements are necessary which should be conducted with standardized measurement systems and under considering of both, physical and microbiological parameters.