There is a growing concern in the population in the Nordic countries regarding the health impact in connection with the releases of odour and bioaerosols as allergens and other compounds from the agricultural sector. Complaints from neighbours to livestock farm houses about odour are getting more and more common. All types of animal households may potentially lead to odour problems, thousands of different odour and bioaerosol compounds released from livestock farming have been identified. Other sources as bioaerosols from livestock has been identified as a potential source for childhood asthma and can cause health risk for farmers working in intensive livestock production units. Odour and gases related to agricultural activity are an international problem partly due to the intensification of concentrated animal production and partly due to the increasing urban population moving closer to farming and livestock production units. The aim of this report is to present a survey of the existing literature, models, available data regarding odour and allergens released from livestock farming and Nordic policy guidelines on odour annoyance thresholds.