Jörg Hartung Institute of Animal Hygiene and Animal Welfare School of Veterinary Medicine Hannover Environmental Concerns 1. There are considerable amounts of effluents from modern animal farming including fish which have distinct impacts on air, water, soil, biodiversity of plants, forest decay and man. 2. There are local impacts caused by odour, bioaerosols and ammonia emissions. There are regional impacts caused by ammonia, nitrate, phosphate and heavy metals. There are global impacts by methane and nitrous oxide. 3. Human health can be affected by air pollutants such as ammonia, hydrogen sulphide or bioaerosols and by drinking water polluted e.g. with nitrates. Trees can suffer from direct impact of ammonia close to farm buildings or manure stores. Forest decay is enhanced by deposition of aerial nitrogen compounds. Biodiversity of plants is endangered by high nitrogen deposition including airborne ammonia. Eutrophication of surface water is promoted by surplus of phosphate and nitrate after manure application. Soil is affected by accumulating residues of growth promoters such as zinc and copper. 4. Mitigation measures for nitrogen, phosphorous and growth promoters are concentrating on balanced composition of diets, efficient use of nutrients in the feed stuff, phase feeding and the addition of phytase. Such feeding strategies have a potential to reduce N emissions by 30 to 40 %, P emissions by 30 to 50 % and zinc and copper to sustainable levels. Abatement techniques such as biofilters and bioscrubbers are available to reduce the airborne emissions. 5. No clear results are presently available on the fate of drugs such as antibiotics from animal treatment in the environment. 6. No clear data are available on safe distances between farms to prevent transmission of infections diseases and on safe distances between farms and residential areas to prevent transmissions of dust, bacteria, fungi, allergenes and endotoxins. 7. Recommendations: Environmental standards for animal production should be established and applied to all (exporting) countries. A risk analysis is necessary for different production systems and regions in the world. The development of low-emission production systems should be encouraged.