Bioaerosol

About: Bioaerosol is a research topic. Over the lifetime, 1347 publications have been published within this topic receiving 34791 citations.

Morphology, chemical composition, and bacterial concentration of airborne particulate matter in rabbit farms

Abstract: Livestock houses are major sources of airborne particulate matter (PM), which can originate from manure, feed, feathers, skin and bedding and may contain and transport microorganisms. Improved knowledge of particle size, morphology, chemical and microbiological composition of PM in livestock houses can help identify major sources of PM and contribute to the development of appropriate source-specific reduction techniques. In rabbit production systems, however, there is limited information on specific particle characteristics. The objective of this study was to characterise airborne PM in rabbit farms in terms of morphology, chemical compositions and bacterial concentration in different size fractions. Size-fractioned PM was sampled in the air of 2 rabbit farms, 1 for fattening rabbits and 1 for reproductive does, using a virtual cascade impactor, which simultaneously collected total suspended PM (TSP), PM10 and PM2.5 size fractions. Airborne PM samples were examined by light microscopy and scanning electron microscopy combined with energy dispersive X-ray analysis. Representative samples from potential sources of PM were also collected and examined. Additionally, a methodology to extract bacteria from the collected samples of airborne PM was developed to determine the bacterial concentration per PM size fraction. Results showed that airborne PM in rabbit farms is highly complex in particle morphology, especially in size. Broken skin flakes, disintegrated particles from feed or faecal material from mechanical fracture are the main sources of airborne PM in rabbit farms. Major elements found in rabbit airborne PM were S, Ca, Mg, Na and Cl. Bacterial concentrations ranged from 1.7×10 4 to 1.6×10 6 colony forming units (CFU)/m 3 (TSP); from 3.6×10 3 to 3.0×10 4 CFU/m 3 (PM10); and from 3.1×10 3 to 1.6×10 4 CFU/m 3 (PM2.5). Our results will improve the knowledge on essential particle characteristics necessary to understand PM’s origin in rabbit farms and contribute to its reduction.

Characteristics of Bacterial and Fungal Aerosol in Gymnasia in China

Abstract: This study attempted to find the typical concentration levels of bacterial and fungal bioaerosol in gymnasia in China. The air samples were collected using the 6-stage Andersen impactor inside and outside of buildings. It was found that the total concentrations of outdoor airborne bacteria and fungi were 342 CFUm–3 and 287 CFUm–3, respectively. The typical levels of bacterial and fungal aerosol indoors were averaged to 901 and 586 CFUm–3 in spectating area, 476 and 245 CFUm–3 in game area, 674 and 402 CFUm–3 in locker room, and 263 and 231 CFUm–3 in office room. The dominant genera identified in gymnasia were Micrococcus spp, Staphylococcus spp, Bacillus spp, and Corynebacterium spp, which amounted to over 80% of the total indoor airborne bacteria. Most frequently occurred indoor fungi were Cladosporium spp, Penicillium spp, Aspergillus spp, and Alternaria spp, constituting over 95% of the total airborne fungi. Bacterial aerosols showed the highest collection rates at F-1 and F-2 stage in the spectating and game areas, F-1, F-2 and F-5 stage in locker rooms, and F-1, F-2, F-4 and F-5 stage in office rooms, while fungal aerosols showed the highest collection rates at F-3 stage in four locations.

Consistency and Reproducibility of Bioaerosol Delivery for Infectivity Studies on Mice

Abstract: : Questions about the clinical significance of an antimicrobial resin use don personal respirators led system to generate consistent test bioaerosols for use in animal studies. The hypothesis was proposed that an aerosol delivery system based on the Collision nebulizer can be designed and engineered to provide, at selectable concentrations, a respiratory challenge of bioaerosol particles that is verifiably consistent in time and that can be fed in separate experiments through treated and untreated filters to deliver a consistent challenge to a small-animal model of human respiration. To verify this hypothesis, such an experimental filtration system was designed and built. Challenge trials were performed with MS2 bacteriophage and Bacillus atrophaeus. Over 30 to 40 minutes, the particle size distribution (PSD) was measured, and viability of microorganisms collected in All-Glass Impingers (AGI-4s) was determined. Concentrations of particles and microorganisms downstream of the filter were too low to measure, and the viable counts for MS2 bacteriophage were not measured at all owing to problems with the assay method. However, in each experiment, the coefficients of variations (CVs) of time-series measurements of the total particle count, count median diameter, and geometric experiments with viability data, all CVs of time-series measurements of upstream viable airborne concentration were less than 26%. This CV is somewhat higher than has been reported in the literature for tests with airborne Bacillus spores, but the plating method used to measure the viability may have introduced additional variation that was not caused within the system itself. It can be reasoned based on this data that the system can provide a sufficiently steady aerosol challenge to be used for later studies using a small-animal model of human respiration. The system provides a design for an animal exposure system incorporating aerosol filtration, which is a capability previously unreported.

Assessment of the potential risks of airbone microbial contamination in solid recovered fuel plants: a case study in istanbul

Abstract: In this pilot study, exposure to airborne microorganisms in solid recovered fuel (SRF) plants has been measured. Different steps in SRF production processes such as separation and size reduction can cause generation of airborne microorganisms. Exposure to these biological agents can cause some health problems, so their levels should be measured to assess the potential risks. Therefore, exposure to airborne total bacteria, Gram-negative bacteria, actinomycetes and fungi were measured in the running SRF plant. Sample locations were chosen considering work areas and wind direction in the plant. Airborne microorganisms were collected via AES Sampl air Lite on particular agar plates and incubated for microorganism growth. No thermophilic actinomycetes were obtained from the samples. The measured concentrations of mesophilic heterotrophic bacteria were almost similar at each point throughout the SRF plant (ranged from 920 to 1750 CFU/m ) except the spare waste stock area (427 CFU/m ) and the monitoring room (ranged from 420 to 770 CFU/m3). The highest concentrations were measured near the preshredder (1750 CFU/m ) and in the manual sorting unit (1610 CFU/m ). However, the concentrations of Gram-negative bacteria varied at each point (28 to 700 CFU/m ). Fungi concentrations varied from 280 to 1750 CFU/m and were high near the sorting unit, the ballistic separator, the fine shredder, the end-product stock area and the monitoring room (1750 CFU/m ). The concentrations of mesophilic heterotrophic bacteria, Gram-negative bacteria and fungi did not exceed the recommended limit values.