BIOLOGICAL AND CHEMICAL CONTAMINATION OF THE AIR IN A GROWER-FINISHERPIG BUILDING USING DEEP-LITTER SYSTEMS

Conventional pig-housing facilities expose farmers to high concentrati ons of microorganisms, organic dusts, and gases, all of which are susp ected of causing health problems. A recent method of growing-finishing has been developed which relies upon the use of biotreated litter, i. e. litter composed of solid waste, sawdust or straw, and a biotechnolo gically produced enzyme that acts on ammoniacal nitrogen in pig manure to stimulate fermentation. The surface of the litter is stirred once a week to maintain aerobic conditions within the litter. The deep-litt er method is supposed to produce compost which can be used to improve the physical, chemical, and biological properties of soil. This projec t was undertaken to measure the chemical and biological contaminants p resent in the air of a grower-finisher pig building using the deep-lit ter method and assess the safety of these workplaces for workers. Whil e the concentrations of contaminants usually found in pig-housing faci lities, such as Gram-negative bacteria and gases, were within acceptab le limits, this type of facility offers ideal conditions for the proli feration of thermophilic actinomycetes and A. fumigatus. Given the unr esolved risks associated with thermophilic actinomycetes and A. fumiga tus, it is recommended that workers in this environment wear HEPA-equi pped (High Efficiency Particulate Air Filters) masks capable of captur ing 99.7% of the spores.