Bioaerosol

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

Physical and Biological Properties of Bioaerosols

Abstract: Bioaerosols include bacterial cells and spores, viruses, pollen, fungi, algae, detritus, allergens and cell fragments. Bioaerosol particles are usually a small fraction of all aerosol particles in our surroundings, but their impact can be critical. They are a means for transmission of disease, they cause allergic reactions and they have effects on the global climate, ecology and biodiversity. This chapter provides an overview of the main types of bioaerosol particles, their sources, transport and sinks, and their potential effects on health and atmosphere.

The evaluation of microbial contamination in the working environment of tanneries.

Abstract: BACKGROUND Due to their animal material processing, tannery workers may be exposed to biological agents. The aim of the study was the microbial contamination assessment of tanneries with different production specifications. Health risk was estimated based on particle size distribution. Moreover, indicators of microbial contamination of tanneries were selected. MATERIALS AND METHODS The studies were conducted in 2 types of tanneries - processing raw hides and producing chrome-tanned leather. Air was sampled with MAS-100 Eco Air Sampler, leathers using RODAC Envirocheck contact plates and swab method, microbial numbers were determined by a culture method. For the bioaerosols size distribution analysis, a six-stage Andersen sampler was used; identification was performed using microscopy and biochemical methods. Microbial contamination was identified by 16S RNA and ITS1/2 rDNA analysis for bacteria and fungi respectively. RESULTS The microbial number in the air ranged between 1.2 x 10(3) and 3.7 x 10(3) CFU/m3. While on the leather, it ranged between 7.6 x 10(1) and 5.5 x 10(5) CFU/100 cm2. Bacteria dominated in the tanneries (air: 51-92%, leathers: 60-100%). Results indicate that potential health risks arise from the fungal small bioaerosol particles presence (0.65-2.1 microm). Eleven indicator microorganisms were determined: B. pumilus, B. subtilis, B. cereus, C. lubricantis, C. cladosporioides, P. commune, P. echinulatum, P. chrysogenum, P. crustosum C. parapsilosis and C. albidus. CONCLUSIONS Microbial contamination evaluation in the tanneries showed the increased bacteria and fungi number in the air in relation to the outdoor air, which indicates an occupational inhalation risk to workers. The designated indicators of microbial contamination in the tanneries are associated with their specific and potentially pathogenic working environment.

Estimation of bioaerosol in indoor environment in the university

Abstract: min for 1 min. This study reveals interesting relationship between the concentration of fungal spores and bacteria in relation to both environmental and human factor. Most observed fungal species detected in the samples were Rhizopus oryzae, Aspergillus nidulans and Aspergillus flavus. Specific bacterial identification was not possible but Gram staining followed by microscopic analysis helped in deriving the different shapes of bacteria collected. Bacillus and Coccus were found maximally. Indoor/Outdoor ratio above 1 for fungal spores signified higher source in the indoor environment at different sections. In indoor environment highest fungal concentration was found in Basement (3140 -3 -3 colony-forming units (CFU) m ) while lowest in 3rd floor (2560 CFU m ). In case of bacterial concentration both Gram negative and positive bacteria were found maximum in the Reading Hall -3 -3 (792 and 696 CFU m , respectively) while lowest in 3rd floor (475 and 437 CFU m , respectively). Higher bacterial counts were primarily attributed to the number of library occupants. High concentration may be due to larger rate of shedding of human skin cells, microbes released from respiratory tract and transport of microbes from floor surfaces on suspended particles.

Integration of high volume portable aerosol-to-hydrosol sampling and qPCR in monitoring bioaerosols

Abstract: In this study, the integration of a high volume, portable aerosol-to-hydrosol sampling technique and quantitative polymerase chain reaction (qPCR) was investigated for bioaerosol monitoring by adapting the RCS High Flow to sample air with mineral-oil-strips. Bacillus subtilis var niger and Pseudomonas fluorescens were aerosolized and collected by the RCS High Flow loaded with mineral-oil-strips for 1, 2 and 5 min. In addition, the adapted aerosol-to-hydrosol sampler was also tested for sampling environmental bacterial aerosols in four different environments (a back yard, a student dorm, a dining hall, and a play ground). The performances of the RCS High Flow with mineral-oil-strips were compared with the use of agar strips under similar conditions in all experiments. Air samples collected by the RCS High Flow were cultured, and in addition those collected with mineral-oil-strips were also quantified using qPCR. When sampling B. subtilis var niger aerosols, the use of mineral-oil-strips was shown to report significantly higher culturable concentrations than those obtained by agar strips regardless of the sampling time tested (p-value = 0.04). In contrast, the differences between the two methods when sampling P. fluorescens aerosols were not statistically significant (p-value = 0.5). When coupled with qPCR, the RCS High Flow loaded with mineral-oil-strips obtained significantly higher bacterial aerosol concentrations than those detected by the culturing method. The sampling time was observed to have negligible effects on the efficiency of the technology developed here. When sampling in different environments, the use of mineral-oil-strip was observed to yield significantly higher, about 4–12 times, culturable bacterial aerosol concentration levels compared to the use of agar. This study demonstrated a high volume (100 L min−1) portable aerosol-to-hydrosol sampling technique, holding broad promise in monitoring airborne biological threats when coupled with qPCR technology. Yet, caution should be taken in relating the bioaerosol concentrations to health risks as qPCR detects both culturable and non-culturable cells including inactivated ones.

Collection characteristics of a batch-type wetted wall bioaerosol sampling cyclone

Abstract: The collection efficiency and sample retention of a batch-type wetted wall bioaerosol sampling cyclone (BWWC) were experimentally characterized. The BWWC is designed to sample air at 400 l/min and concentrate the particles into 12 ml of water. Aerosol is transported into a cylindrically-shaped axial flow cyclone through a tangential slot and the particles are impacted on the inner wall, which is wetted by air shear acting on a liquid pool at the base of the cyclone. The retention of collected particles and the aerosol collection efficiency of the BWWC were evaluated with polystyrene latex beads (PSL), sodium fluorescein/oleic acid droplets, and Bacillus atrophaeus (aka BG) spores. The retention of particles was determined by adding hydrosol directly into the device, running the BWWC for a pre-set period of time, and then determining the amount of particulate matter recovered relative to the initial amount. For 1-μm diameter PSL, 90% of the particles were recoverable from the cyclone body immediately after their introduction; however, only 10% were retained in the collection liquid after 8 h of operation. The aerosol sampling efficiency was determined by comparing the amount of particulate matter collected in the liquid with that collected by a reference filter. The collection efficiency was 50–60% for 1- and 3-μm polystyrene (PSL) particles, and 1.5% for 10-μm oleic acid particles. The efficiency for 3-μm oleic acid droplets was 35%. Explanations are provided for the difference between liquid and solid particle behavior, and for the low efficiency for the large liquid particles. The collection efficiency for single spore BG was slightly lower than that for 1-μm PSL.