Current developments in air pollution prevention

Mit der Novellierung der NEC-Richtlinie müssen in Deutschland bis zum Jahr 2030 die Ammoniakemissionen um 29 % auf dann 482 Kilotonnen gesenkt werden und die Feinstaubemissionen (PM 2,5) um 43 %. Für die Ammoniakemissionen ist die Landwirtschaft Hauptemittent. Hier müssen in Zukunft verstärkt emissionsvermeidende und emissionsmindernde Verfahren eingesetzt werden. Die Abluftreinigung leistet dazu einen wichtigen Beitrag, kann aber allein aus wirtschaftlichen Gründen nicht bei kleineren Stallgebäuden flächendeckend eingesetzt werden. Daher werden alternative Verfahren mit ähnlich hoher Reduktionseffizienz benötigt. Hier sind eine angepasste Abluftreinigung mit Umluftwäschern und die Güllebehandlung besonders vielversprechend. Der Fokus sollte zudem mehr auf die Rinderhaltung gelegt werden, da sie einen Großteil der gasförmigen Emissionen (auch Methan) pro-duziert und es bisher hier die wenigsten Emissionsdaten und vor allem kaum technische Lösungen zur Emissionsminderung gibt.With the amendment of the NEC Directive the ammonia emissions in Germany will have to be reduced by 29% to 482 kilotons by the year 2030, and fine particulate emissions (PM 2.5) even shall be reduced by 43%. Agriculture is the major emission source for ammonia. Here more emission-reducing and mitigating procedures have to be used in the future. The exhaust air purification makes an important contribution to this. Though, in its current form it cannot be used on large scale for smaller sheds at least because of economic reasons. Therefore, alternative methods with similarly high reduction efficiencies are required. Here, adapted exhaust air purification with recirculating air cleaners and the liquid manure treatment are particularly promising. The future focus should also be on cattle since cattle farming produces a large proportion of gaseous emissions (including methane), and so far there are very few emissions data and, above all, hardly any technical solutions for emission reduction

Der Auslauf in der ökologischen Schweinemast: Verschmutzungsverteilung und Ammoniakemissionen

Ammonia emissions are an important problem in agricultural systems. Organic pig production raises a claim to offer high animal welfare. However, gaseous emissions can exhaust out of outdoor runs. Many measurement technics to determine the ammonia volatilization in animal facilities exist. In outdoor runs it is necessary to define the air volume flow. In addition, the contaminated surface of the pig-yard is heterogeneous. Therefore, it is interesting if the ammonia concentration correlate with the amount of manure. The outdoor run has been divided in a matrix. The ammonia concentrations are determined with a multi-gas monitor (INNOVA 1312) in combination with a dynamic chamber. The study showed a difference in ammonia volatilization between roofed and unroofed outdoor runs. Furthermore there is a high variability of the Ammonia concentrations in the different patches of the matrix

Differenzierte Bioaerosolmessungen: Größenfraktionierte und kontinuierliche Messung von Bioaerosolen in der Emission von Geflügelhaltungen

Es wurden erstmals die Größenverteilungen von Bioaerosolen, sowie deren tageszeitlicher Konzentrationsverlauf in der Emission von Anlagen zur Geflügelhaltung mittels standardisierter Verfahren bestimmt. Die Ergebnisse richten sich im Rahmen von Genehmigungsverfahren an Anlagenbetreiber, Gutachter und Behörden. Sie legen nahe, dass zukünftig sowohl die Partikelgrößenverteilung, als auch die tageszeitlichen Emissionsschwankungen bei der Ausbreitungsrechnung von Bioaerosolen berücksichtigt werden sollten. Bezüglich der verwendeten Emissionsfaktoren wird eine Halbierung des Konventionswertes für Legehennen und Putenmast aufgezeigt, bezüglich des Größenklassenspektrums für Anlagen der Geflügelhaltung eine Aufteilung von 15 % PM 2,5; 25 % PM 10; und 60 % TSP. Redaktionsschluss: 31.01.201

Tenazität luftgetragener Mikroorganismen: Untersuchung der Tenazität luftgetragener Mikroorganismen unter möglichst realen Außenluftbedingungen: Abschlussbericht zum Projekt TeluMi

Über die Abluft aus Tierhaltungsanlagen emittieren große Mengen Mikroorganismen in die Umwelt und können auch in benachbarte Wohngebiete gelangen. Dort stehen sie in Verdacht, die Gesundheit der Anwohner negativ zu beeinflussen. Ziel dieses dreijährigen Forschungsprojektes war es, die Absterberaten (Tenazität) von für Tierhaltungsanlagen spezifischen Bakterien unter Außenluftbedingungen quantitativ zu bestimmen und die wichtigsten meteorologischen Parameter zu identifizieren, die einen Einfluss darauf haben. Es wurde eine spezielle Messkammer entwickelt mit deren Einsatz Absterberaten in Verbindung mit hohen Globalstrahlungswerten von deutlich über 90 % festgestellt werden konnten. Die Veröffentlichung richtet sich an Betreiber landwirtschaftlicher Tierhaltungsanlagen oder anderer Bioaerosol-emittierender Anlagen, an Gutachter im Allgemeinen oder für Ausbreitungsberechnungen im Speziellen sowie an Genehmigungsbehörden, die mit der Thematik der Bioaerosole befasst sind. Die Veröffentlichung kann aber auch für jeden allgemein Interessierten interessant sein, der sich fragt, wie lange Mikroorganismen in der Atmosphäre in einem für sie lebensfeindlichen Umfeld überleben. Redaktionsschluss: 30.10.202

Demands and measures for emission reduction in animal husbandry

Der vorliegende Beitrag beschreibt zunächst die rechtlichen Anforderungen an die Tierhaltung in Deutschland, die insbesondere für größere gewerbliche Tierhaltungsbetriebe deutlich verschärft worden sind. Darüber hinaus werden verschiedene Maßnahmen zur Emissionsminderung vorgestellt. Für große Tierhaltungsbetriebe wird die Abluftreinigung eine steigende Bedeutung erlangen. Steigende Energiekosten für die Lüftung von Tierhaltungsanlagen erfordern neue Lüftungskonzepte sowie Maßnahmen zur Zuluftkonditionierung, die neben der Energieeinsparung auch zur Emissionsminderung beitragen.The present contribution describes at first the legal demands on livestock in Germany which have been clearly tightened for larger commercial livestock farms in particular. Beyond that different options for emission reduction are introduced. For large animal husbandries the exhaust air treatment will become important. Increasing energy costs for ventilation of animal stables require new ventilation concepts and measures of inlet air conditioning as well, which both contribute to energy saving and emission reduction

Emission of bioaerosols from livestock facilities - Methods and results from available bioaerosol investigations in and around agricultural livestock farming

The present report reviews literature from throughout the world on methods and results of bioaerosol investigations in and around agricultural livestock farming and summarises the most important points. The global trend towards intensification and industrialisation of animal production, with regional concentration of livestock facilities and increasing numbers of animals and greater stock densities, has led to an increase in bioaerosol emissions to the environment in certain areas and to increasing concern about health impairment of the population in the vicinity. The main sources of the bioaerosols are the animals and their faeces, the litter and feed. If the particles become airborne, they can be emitted from the stables into the environment. Hundreds of different viruses, bacteria and moulds have been detected in agricultural livestock farming worldwide. The bacterial group of the Staphylococcaceae appears to be most suitable for animal husbandry as a specific indicator or guiding parameter. Bioaerosols can be measured online with particle spectrometers and offline using classical methods, i.e. sampling on site with subsequent evaluation by means of culture-based or molecular biological methods in the laboratory. The classical detection methods are best suited to the complexity of bioaerosols in agricultural livestock farming. The sampling of bioaerosols should be carried out as far as possible using standardised systems that have high physical and biological collection efficiency, in order to ensure comparability of the data. The selection of a suitable collection system should primarily depend on the issue in question. After the bioaerosols have been collected in a sample, evaluation is usually carried out via cultivation and / or various biochemical and molecular biological methods. Especially the latter, in combination with the classical culture-based methods, enable a detailed insight into the composition of bioaerosols. However, further standardisation of the methods for bioaerosols is necessary here. Endotoxins, on the other hand, are predominantly detected using the LAL test, although this test remains relatively susceptible to disturbances. Most data on bioaerosol measurements in agricultural livestock farming available for this review are from the USA and Germany. Here, the concentrations of bacteria, moulds and endotoxins were measured in the stalls of pigs, cattle and chickens. The highest concentrations of airborne bacteria were found in stalls for chickens, followed by turkeys, ducks, sheep, goats, pigs, cattle, horses and rabbits, with the different husbandry and production stages having a significant influence. Emission factors published for airborne microorganisms also differ in part considerably depending on the animal species and the type of keeping, also as a result of different sampling conditions, collection methods and different methods for determination of the concentrations. The concentrations of the airborne bacteria in livestock during the day and night can deviate by a factor of ten. The deviation may further increase by a factor of 1000 if emission factors are calculated on the basis of the specific volumetric flow rates. This must be taken into account in the calculation of annual average values of emission factors. During transportation, i.e. the transport of bioaerosols via the air, the microorganisms are largely exposed to wind and weather. The extent to which they are carried is primarily dependent on two parameters: the tenacity, i.e. the ability to survive the airborne condition, and the size and composition of the bioaerosol particles, i.e. how quickly they sediment. How long microorganisms are viable in the air is dependent on very many factors and, due to the relatively unsuitable test systems used in the past, this aspect has not been studied sufficiently. Regarding particle size, most of the airborne microorganisms found in livestock farming have a significantly larger particle size or mass fraction than would be expected from the size of the individual cells of the organisms. 30% to 70% of the bacteria can be found in mass fractions larger than PM10, whereby the distribution of the different bioaerosol components can vary considerably and is not uniformly correlated with the distribution of the dust fractions. The immission concentrations of bioaerosols exponentially decrease with the distance from the emission source, mainly depending on the particle size and meteorological conditions. Instead of carrying out complex measurements, the spread of bioaerosols can also be simulated with computer models. Up to now, however, these models have often overestimated the emissions, since night reduction, particle size distributions and death rates of the microorganisms are still not taken into account. From hundreds of publications, it has long been known that bioaerosols, probably interacting synergistically with other air pollutants, have a negative impact on the health of people who work in animal stalls and also on that of the animals. No dose / effect relationship has been established so far. To date there has been no clear statement as to the possible danger to residents living in the vicinity of livestock farms. Therefore, no general limit values have been formulated for bioaerosols, above which a detrimental effect on health is to be expected, except to a certain extent for endotoxins. Instead, an environmental assessment of individual cases usually takes place as a precautionary principle. A number of precautionary measures are available to reduce bioaerosol emissions. Thanks to good stall management and a hygiene concept supported by technical solutions, e.g. exhaust air cleaning, a significant reduction of bioaerosols originating from livestock husbandry of well over 90% can be achieved. It remains to be seen whether a dose/response relationship for bioaerosols or at least a valid environmental medical assessment of the emissions will be possible in the future. Until then, in the medium term, the indicator organisms and guiding parameters for bioaerosols from livestock husbandry should be (re)considered and viruses should be included. This comprises the validation and further development of high-volume collectors for bioaerosols. In the case of dispersion modelling, the particle size distributions of the microorganisms and the different levels of emissions between day and night must be considered for the short term. This also applies to tenacity, where new measurement systems are needed in order to obtain meaningful data. It should also be a medium-term goal to reduce bioaerosol concentrations already in the stalls. Concepts for adapted exhaust air cleaning systems are available for this purpose, which, together with further measures, can lead to a reduction of 90% to 99%. There is still a lot to do

Emission von Bioaerosolen aus Tierhaltungsanlagen - Methoden und Ergebnisse verfügbarer Bioaerosoluntersuchungen in und um landwirtschaftliche Nutztierhaltung

The global trend towards intensification and industrialization of animal production with regional concentration of livestock plants and increasing numbers of animals and stockpiles leads to a raise in bioaerosol emissions to the environment in certain areas and to an increasing concern about health impairment of the population in the vicinity. The essential sources of the bioaerosols are the animals and their faeces, the litter and the feed. The particles from there get into the airborne state and emit from the stables also into the environment. Hundreds of different viruses, bacteria and mold fungi have been detected worldwide in agricultural livestock farming. The bacterium group of the Staphylococcaceae appears to be most suitable for animal husbandry as a specific indicator or guiding parameter. Bioaerosols can be measured online with particle spectrometers and offline using classical methods, i. e. sampling on site with subsequent evaluation by means of culture-based or molecular biological methods in the laboratory. The classical detection methods are best suited to the complexity of bioaerosols in agricultural livestock farming. The sampling of bioaerosols should be carried out as far as possible using standardized systems which have high physical and biological collection efficiency in order to ensure comparability of the data. The selection of the collection system should always depend on the question primarily. After the bioaerosols have been collected in a sample, the evaluation is usually carried out via cultivation and / or various biochemical and molecular biological methods. Especially the latter allow, in combination with the classical culture-based methods, for a detailed insight into the composition of bioaerosols. But here a further standardization of the methods for bioaerosols is necessary. Endotoxins, on the other hand, are predominantly detected by the LAL test, which, however, is still very susceptible to disturbances. Most data on bioaerosol measurements in agricultural livestock farming available for this review are from the USA and Germany. Here, the concentrations of bacteria, molds and endotoxins were measured in the stables of pigs, cattle and chickens. The highest concentrations of airborne bacteria were found in stables for chickens, followed by turkeys, ducks, sheep, goats, pigs, cattle, horses and rabbits, with the different husbandry and production stages having a significant influence. In the emission of the stables, the published emission factors for airborne microorganisms differ considerably for the animal species and part of the keeping system, also by the different sampling conditions, collection methods and different methods for the determination of the concentrations. The concentrations of the airborne bacteria in livestock during the day and night can deviate by a factor of ten. The deviation may further increase to a factor of 1000 if emission factors are calculated on the basis of the specific volumetric flow rates. This must be taken into account in the calculation of annual average values of emission factors. During transportation, i. e. the transport of bioaerosols via the air, the micro-organisms are largely exposed to wind and weather. The extent to which they are carried is primarily dependent on two parameters: the tenacity, i. e. the ability to survive the airborne condition, and the size and composition of the bioaerosol particles, i. e. how quickly they sediment. How long microorganisms are viable in the air is depending on very many factors and, due to the previously used test systems, only insufficiently studied. Regarding the particle size, most of the air-borne microorganisms are found in the agricultural livestock farming in significantly larger particle size or mass fractions than the size of the individual cells of the organisms can be assumed. 30% to 70% of the bacteria can be found in mass fractions larger than PM10 though, where the distribution of the different bioaerosol components can be very different and not uniformly correlated with the distribution of the dust fractions. The immission concentrations of bioaerosols exponentially decrease with the distance to the emission source, mainly depending on the particle size and meteorological conditions. Instead of carrying out complex measurements, the spread of bioaerosols can also be simulated with computer models. Up to now, however, the models have often surpassed the emissions, since night reduction, particle size distributions and abortions are still not taken into account. From hundreds of publications, it has been known for a long time that bioaerosols probably interact synergistically with other air pollutants on livestock breeders' health, of the staff working there and also the animals. No dose / effect relationship has been established so far. To date there has been no clear statement as to the possible danger to the inhabitants of animal husbandry. Therefore, no general limit values are formulated for bioaerosols, except for a certain extent for endotoxins, which can be expected to have a detrimental effect on health. Instead, an environmental assessment of individual cases usually takes place from the precautionary principle. A number of measures are available to reduce the bio-aerosol emissions as a precaution. Thanks to a good stable management and hygienic concept supported by technical solutions, for example, the exhaust air purification, a significant reduction of livestock husbandry originating bioaerosols of well over 90% can be achieved. Whether in the future the derivation of a dose / response relationship for bioaerosols or at least a valid environmental medical assessment of the emissions is possible remains to be seen. Until then, in the medium term, the indicator organisms and guiding parameters for bioaerosols from livestock husbandry should be (re)considered and viruses should be included. This comprises the validation and further development of high-volume collectors for bioaerosols. In the case of dispersion modelling, the particle size distributions of the microorganisms and the different levels of emissions between day and night must be considered for the short term. This also applies to the tenacity, where new measurement systems are needed in order to obtain meaningful data. It should also be a medium-term goal to reduce the bio-aerosol concentrations already in the stable. Concepts for adapted exhaust air purification plants are available for this purpose, which together with further measures can lead to a reduction of 90% to 99%. There still is a lot to do

Emission of bioaerosols from livestock facilities - Methods and results from available bioaerosol investigations in and around agricultural livestock farming

The present report reviews literature from throughout the world on methods and results of bioaerosol investigations in and around agricultural livestock farming and summarises the most important points. The global trend towards intensification and industrialisation of animal production, with regional concentration of livestock facilities and increasing numbers of animals and greater stock densities, has led to an increase in bioaerosol emissions to the environment in certain areas and to increasing concern about health impairment of the population in the vicinity. The main sources of the bioaerosols are the animals and their faeces, the litter and feed. If the particles become airborne, they can be emitted from the stables into the environment. Hundreds of different viruses, bacteria and moulds have been detected in agricultural livestock farming worldwide. The bacterial group of the Staphylococcaceae appears to be most suitable for animal husbandry as a specific indicator or guiding parameter. Bioaerosols can be measured online with particle spectrometers and offline using classical methods, i.e. sampling on site with subsequent evaluation by means of culture-based or molecular biological methods in the laboratory. The classical detection methods are best suited to the complexity of bioaerosols in agricultural livestock farming. The sampling of bioaerosols should be carried out as far as possible using standardised systems that have high physical and biological collection efficiency, in order to ensure comparability of the data. The selection of a suitable collection system should primarily depend on the issue in question. After the bioaerosols have been collected in a sample, evaluation is usually carried out via cultivation and / or various biochemical and molecular biological methods. Especially the latter, in combination with the classical culture-based methods, enable a detailed insight into the composition of bioaerosols. However, further standardisation of the methods for bioaerosols is necessary here. Endotoxins, on the other hand, are predominantly detected using the LAL test, although this test remains relatively susceptible to disturbances. Most data on bioaerosol measurements in agricultural livestock farming available for this review are from the USA and Germany. Here, the concentrations of bacteria, moulds and endotoxins were measured in the stalls of pigs, cattle and chickens. The highest concentrations of airborne bacteria were found in stalls for chickens, followed by turkeys, ducks, sheep, goats, pigs, cattle, horses and rabbits, with the different husbandry and production stages having a significant influence. Emission factors published for airborne microorganisms also differ in part considerably depending on the animal species and the type of keeping, also as a result of different sampling conditions, collection methods and different methods for determination of the concentrations. The concentrations of the airborne bacteria in livestock during the day and night can deviate by a factor of ten. The deviation may further increase by a factor of 1000 if emission factors are calculated on the basis of the specific volumetric flow rates. This must be taken into account in the calculation of annual average values of emission factors. During transportation, i.e. the transport of bioaerosols via the air, the microorganisms are largely exposed to wind and weather. The extent to which they are carried is primarily dependent on two parameters: the tenacity, i.e. the ability to survive the airborne condition, and the size and composition of the bioaerosol particles, i.e. how quickly they sediment. How long microorganisms are viable in the air is dependent on very many factors and, due to the relatively unsuitable test systems used in the past, this aspect has not been studied sufficiently. Regarding particle size, most of the airborne microorganisms found in livestock farming have a significantly larger particle size or mass fraction than would be expected from the size of the individual cells of the organisms. 30% to 70% of the bacteria can be found in mass fractions larger than PM10, whereby the distribution of the different bioaerosol components can vary considerably and is not uniformly correlated with the distribution of the dust fractions. The immission concentrations of bioaerosols exponentially decrease with the distance from the emission source, mainly depending on the particle size and meteorological conditions. Instead of carrying out complex measurements, the spread of bioaerosols can also be simulated with computer models. Up to now, however, these models have often overestimated the emissions, since night reduction, particle size distributions and death rates of the microorganisms are still not taken into account. From hundreds of publications, it has long been known that bioaerosols, probably interacting synergistically with other air pollutants, have a negative impact on the health of people who work in animal stalls and also on that of the animals. No dose / effect relationship has been established so far. To date there has been no clear statement as to the possible danger to residents living in the vicinity of livestock farms. Therefore, no general limit values have been formulated for bioaerosols, above which a detrimental effect on health is to be expected, except to a certain extent for endotoxins. Instead, an environmental assessment of individual cases usually takes place as a precautionary principle. A number of precautionary measures are available to reduce bioaerosol emissions. Thanks to good stall management and a hygiene concept supported by technical solutions, e.g. exhaust air cleaning, a significant reduction of bioaerosols originating from livestock husbandry of well over 90% can be achieved. It remains to be seen whether a dose/response relationship for bioaerosols or at least a valid environmental medical assessment of the emissions will be possible in the future. Until then, in the medium term, the indicator organisms and guiding parameters for bioaerosols from livestock husbandry should be (re)considered and viruses should be included. This comprises the validation and further development of high-volume collectors for bioaerosols. In the case of dispersion modelling, the particle size distributions of the microorganisms and the different levels of emissions between day and night must be considered for the short term. This also applies to tenacity, where new measurement systems are needed in order to obtain meaningful data. It should also be a medium-term goal to reduce bioaerosol concentrations already in the stalls. Concepts for adapted exhaust air cleaning systems are available for this purpose, which, together with further measures, can lead to a reduction of 90% to 99%. There is still a lot to do

Emission von Bioaerosolen aus Tierhaltungsanlagen - Methoden und Ergebnisse verfügbarer Bioaerosoluntersuchungen in und um landwirtschaftliche Nutztierhaltung

The global trend towards intensification and industrialization of animal production with regional concentration of livestock plants and increasing numbers of animals and stockpiles leads to a raise in bioaerosol emissions to the environment in certain areas and to an increasing concern about health impairment of the population in the vicinity. The essential sources of the bioaerosols are the animals and their faeces, the litter and the feed. The particles from there get into the airborne state and emit from the stables also into the environment. Hundreds of different viruses, bacteria and mold fungi have been detected worldwide in agricultural livestock farming. The bacterium group of the Staphylococcaceae appears to be most suitable for animal husbandry as a specific indicator or guiding parameter. Bioaerosols can be measured online with particle spectrometers and offline using classical methods, i. e. sampling on site with subsequent evaluation by means of culture-based or molecular biological methods in the laboratory. The classical detection methods are best suited to the complexity of bioaerosols in agricultural livestock farming. The sampling of bioaerosols should be carried out as far as possible using standardized systems which have high physical and biological collection efficiency in order to ensure comparability of the data. The selection of the collection system should always depend on the question primarily. After the bioaerosols have been collected in a sample, the evaluation is usually carried out via cultivation and / or various biochemical and molecular biological methods. Especially the latter allow, in combination with the classical culture-based methods, for a detailed insight into the composition of bioaerosols. But here a further standardization of the methods for bioaerosols is necessary. Endotoxins, on the other hand, are predominantly detected by the LAL test, which, however, is still very susceptible to disturbances. Most data on bioaerosol measurements in agricultural livestock farming available for this review are from the USA and Germany. Here, the concentrations of bacteria, molds and endotoxins were measured in the stables of pigs, cattle and chickens. The highest concentrations of airborne bacteria were found in stables for chickens, followed by turkeys, ducks, sheep, goats, pigs, cattle, horses and rabbits, with the different husbandry and production stages having a significant influence. In the emission of the stables, the published emission factors for airborne microorganisms differ considerably for the animal species and part of the keeping system, also by the different sampling conditions, collection methods and different methods for the determination of the concentrations. The concentrations of the airborne bacteria in livestock during the day and night can deviate by a factor of ten. The deviation may further increase to a factor of 1000 if emission factors are calculated on the basis of the specific volumetric flow rates. This must be taken into account in the calculation of annual average values of emission factors. During transportation, i. e. the transport of bioaerosols via the air, the micro-organisms are largely exposed to wind and weather. The extent to which they are carried is primarily dependent on two parameters: the tenacity, i. e. the ability to survive the airborne condition, and the size and composition of the bioaerosol particles, i. e. how quickly they sediment. How long microorganisms are viable in the air is depending on very many factors and, due to the previously used test systems, only insufficiently studied. Regarding the particle size, most of the air-borne microorganisms are found in the agricultural livestock farming in significantly larger particle size or mass fractions than the size of the individual cells of the organisms can be assumed. 30% to 70% of the bacteria can be found in mass fractions larger than PM10 though, where the distribution of the different bioaerosol components can be very different and not uniformly correlated with the distribution of the dust fractions. The immission concentrations of bioaerosols exponentially decrease with the distance to the emission source, mainly depending on the particle size and meteorological conditions. Instead of carrying out complex measurements, the spread of bioaerosols can also be simulated with computer models. Up to now, however, the models have often surpassed the emissions, since night reduction, particle size distributions and abortions are still not taken into account. From hundreds of publications, it has been known for a long time that bioaerosols probably interact synergistically with other air pollutants on livestock breeders' health, of the staff working there and also the animals. No dose / effect relationship has been established so far. To date there has been no clear statement as to the possible danger to the inhabitants of animal husbandry. Therefore, no general limit values are formulated for bioaerosols, except for a certain extent for endotoxins, which can be expected to have a detrimental effect on health. Instead, an environmental assessment of individual cases usually takes place from the precautionary principle. A number of measures are available to reduce the bio-aerosol emissions as a precaution. Thanks to a good stable management and hygienic concept supported by technical solutions, for example, the exhaust air purification, a significant reduction of livestock husbandry originating bioaerosols of well over 90% can be achieved. Whether in the future the derivation of a dose / response relationship for bioaerosols or at least a valid environmental medical assessment of the emissions is possible remains to be seen. Until then, in the medium term, the indicator organisms and guiding parameters for bioaerosols from livestock husbandry should be (re)considered and viruses should be included. This comprises the validation and further development of high-volume collectors for bioaerosols. In the case of dispersion modelling, the particle size distributions of the microorganisms and the different levels of emissions between day and night must be considered for the short term. This also applies to the tenacity, where new measurement systems are needed in order to obtain meaningful data. It should also be a medium-term goal to reduce the bio-aerosol concentrations already in the stable. Concepts for adapted exhaust air purification plants are available for this purpose, which together with further measures can lead to a reduction of 90% to 99%. There still is a lot to do

Differenzierte Bioaerosolmessungen: Größenfraktionierte und kontinuierliche Messung von Bioaerosolen in der Emission von Geflügelhaltungen

Es wurden erstmals die Größenverteilungen von Bioaerosolen, sowie deren tageszeitlicher Konzentrationsverlauf in der Emission von Anlagen zur Geflügelhaltung mittels standardisierter Verfahren bestimmt. Die Ergebnisse richten sich im Rahmen von Genehmigungsverfahren an Anlagenbetreiber, Gutachter und Behörden. Sie legen nahe, dass zukünftig sowohl die Partikelgrößenverteilung, als auch die tageszeitlichen Emissionsschwankungen bei der Ausbreitungsrechnung von Bioaerosolen berücksichtigt werden sollten. Bezüglich der verwendeten Emissionsfaktoren wird eine Halbierung des Konventionswertes für Legehennen und Putenmast aufgezeigt, bezüglich des Größenklassenspektrums für Anlagen der Geflügelhaltung eine Aufteilung von 15 % PM 2,5; 25 % PM 10; und 60 % TSP