Farmers' Exposure to Airborne Microorganisms in Composting Swine Confinement Buildings

Abstract

Farmers' exposure to airborne microorganisms was studied in 12 composting swine confinement buildings and in 7 buildings with traditional slatted-floor pit systems. Airborne cultivable mesophilic, xerophilic, and thermotolerant fungi, mesophilic bacteria, and thermophilic actinobacteria were determined with a six-stage impactor. Furthermore, the total concentrations of microorganisms were determined with filter sampling and direct count using a microscope. In swine confinement buildings where the composting system was functioning properly, the concentrations of microorganisms were 10-1000 times higher than in traditional swine buildings. High concentrations of thermotolerant fungi and thermophilic actinobacteria (up to 10(5) CFU/m(3)), which have been considered to be the main causative agents of farmer's lung, were found in the composting swine confinement buildings that were studied. The conclusion was reached that farmers are exposed to high concentrations of fungal and actinobacterial spores also in swineries, at least in composting confinement buildings. Therefore, personal protection is strongly recommended in composting swineries, especially during the turning of the compost bed.

Distribution characteristics of airborne bacteria and fungi in the feedstuff-manufacturing factories

“…Compared with previous data from livestock production plants like dairy cattle shed, pig building and chicken-caged house where organic materials are primarily treated [2][3][4][5][6][7], the degree of air contamination by microorganism in the feedstuff factory was relatively low. The methods used in precedent studies for the measurement of indoor airborne microorganism can be largely divided into absorption method, filtering method and inertial impaction method [31].…”

“…The principal reason for grain dust to provoke allergic respiratory disease is that it can play a role as an infectious aerosol because its organic materials provide essential nutrients for airborne microorganisms adhered to surface of grain dust [1]. The fact that there is positive correlation between emission of grain dust and bioaerosol level can be explained by many reports on the bioaerosol exposures and associated respiratory health hazards during handling of livestock food and fodder in livestock production plants like dairy cattle shed [2], pig building [3][4][5][6] and chicken-caged house [7]. Based on this fact, it is assumed that feedstuff-manufacturing factory which treats organic material would probably show high bioaerosol level.…”

“…As addressed hereinbefore, it is reported previously that the exposure levels of airborne microorganism in organic materials treating workplaces such as livestock production plants [2][3][4][5][6][7], organic waste disposal plants [27,28] and sawdust manufacture factories [29] are relatively higher than those in other types of workplace based on our literature search. In the world, however, there is no study focusing on worker's exposure level and distribution characteristics of airborne microorganisms in feedstuff-manufacturing factories.…”

Impact of Production Systems on Swine Confinement Buildings Bioaerosols

“…(12,13,27,28) In SCB with beds of organic material (e.g., peat) and a properly functioning composting system, microorganisms have been recovered in concentrations 10 to 1000 times higher than in traditional buildings. (32) On average, the present study observed culturable mesophilic molds in the SCB with litters in amounts more than 50 times larger (up to 1.89 × 10 5 CFU/m 3 ) than the amounts in the conventional barns. Even though no threshold values exist for fungal exposure in humans, for comparison purposes, respiratory symptoms in humans have already been observed by Donham et al (14) in the presence of culturable mold concentrations higher than 1.3 × 10 4 CFU/m 3 .…”

Exposures and Health Outcomes in Relation to Bioaerosol Emissions From Composting Facilities: A Systematic Review of Occupational and Community Studies

“…There were no studies identified that would enable the estimation of incidence rates of occupational allergic disease, one of the most frequent occupational respiratory disorders. However, respiratory and allergic disease following elevated exposures to some bioaerosols, such as endotoxin and Aspergillus fumigatus (Rautiala et al, 2003), was noted in other occupations including agricultural workers (May et al, 2012;Poole et al, 2010) and domestic waste collectors that were not considered in this review. The lack of longitudinal studies is most likely due to the practical difficulties of longitudinal studies in these settings, and the difficulty in obtaining historical data due to the relatively recent development of the composting industry.…”