Hazards in confinement housing--gases and dusts in confined animal houses for swine, poultry, horses and humans.

Indoor atmospheres in swine or poultry confinement buildings, horse stalls or human dwellings contain gases, dusts and endotoxin in concentrations significantly in excess of those in outdoor environments. Although concentrations of such constituents differ appreciably between species, many of such differences may be related to differences in indoor mass loading and ventilation, or to the homogeneity of such ventilation. The high protein content of these indoor dust particles suggest they are of animal origin. Their ability to form bacterial colonies and to form or bind endotoxin suggest that the smallest and most respirable particles were manure particles containing enteric bacteria and endotoxin. Respiratory disease in swine, poultry and horses and in the workers who care for them may be caused by increased levels of carbon monoxide, ammonia, hydrogen sulfide, or indoor dust particles from feed and manure. The stagnant air of a well-insulated building causes the most active individual to attract these stagnant pockets, while the tendency of young animals to seek warmth may lead to the formation of additional pockets. Increased ventilation is an expensive solution to the problems associated with indoor air pollution. However, more thorough mixing of indoor air may reduce the effects of these clouds of pollutants.