Risks caused by bio-aerosols in poultry houses

Aerial pollutants in confined animal houses are widely recognized as detrimental to the respiratory health of animals kept in these facilities. Primary and opportunistic microbial pathogens may directly cause infectious and allergic diseases in farm animals, and chronic exposure to some types of aerial pollutants may exacerbate multi-factorial environmental diseases. There are, however, few international field surveys paying attention to the health of the farmers and the farm personnel working in such atmospheres, and to the spread of pathogens from farm buildings. Studies reveal that up to 20 percent of farmers and farm workers report work-related symptoms of respiratory affections, such as coughing, sputum and wheezing. Some develop asthma, others develop diseases that are described as ODTS (organic dust toxic syndrome). There are indications that various pathogens can survive in ambient air for several minutes and can be distributed over long distances, (e.g. foot-andmouth disease (FMD) virus more than 50 km, and staphylococcae up to 500 m). This paper describes the complex nature and composition of the aerial pollutants, such as gases, dust, micro-organisms and other compounds, present in the air of farm animal houses, their potential role in the development of respiratory diseases in humans and animals, and their distribution in the surroundings of farms. Future-oriented sustainable farm animal production should (in addition to improving animal welfare, consumer protection, economy and occupational health) enhance standards aimed at preventing or reducing the aerial spread of pathogens.