Bioaerosol

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

Relationship between different bioaerosol parameters sampled from the breathing zone of waste collectors - identification of the most important parameters*

Abstract: Measurements of the exposure to bioaerosols are often necessary in studies on the causality of occupational respiratory problems, but controversy exists on the relevance of different bioaerosol exposure parameters as well as on the proper methods for sampling of bioaerosol and analysis of the parameters. The aim of the present study was to elucidate possible correlations between different general microbiological parameters obtained from personal sampling of bioaerosols on filters, and to identify the parameters most useful in the discrimination between exposure levels of waste collectors. Bioaerosol sampling was carried out with the assistance of Danish waste collectors (n = 199) collecting household waste. For a full work shift each waste collector carried two field monitors (25 mm) with filters for the collection of aerosols. The following general exposure parameters were measured: total dust; endotoxin; total counts of microorganisms by epifluorescence microscopy including differential counts of fungal spores, spherical and rod shaped bacteria; culturable bacteria and fungi on agar plates (viable counts). The relationships between the different parameters were investigated by parametric correlation analysis (Pearsons) after logarithmic transformation of the data. Principal component analysis was used to study the contribution of the parameters with respect to the variance between independent samples of bioaerosols. A statistically significant positive correlation (p < 0.05) was observed between a number of different parameters. However, the correlation coefficients were in all cases low (0.2 < r < 0.7). Consequently, the prediction of a bioaerosol parameter based on data of other parameters is expected to have a limited accuracy and validity. Principal component analysis revealed that total counts of fungal spores and rod shaped bacteria can account for 93% of the variance between independent bioaerosol samples. The result is unlikely to be due to poor analytical performance of the method. It is concluded that the total count parameter may provide the best exposure stratification of waste collectors in epidemiological studies and in routine monitoring of workplace exposure. Address for correspondence: Dr. Otto M. Poulsen, National Institute of Occupational Health, Lersø Parkallé 105, DK-2100 Copenhagen Ø, Denmark. E-mail: omp@ami.dk

Performance evaluation of two personal bioaerosol samplers

Abstract: In this study, the performance of two newly developed personal bioaerosol samplers for monitoring the level of environmental and occupational airborne microorganisms was evaluated. These new personal bioaerosol samplers were designed based on a swirling cyclone with recirculating liquid film. The performance evaluation included collection efficiency tests using inert aerosols, the bioaerosol survival test using viable airborne microorganism, and the evaluation of using non-aqueous collection liquid for long-period sampling. The test results showed that these two newly developed personal bioaerosol samplers are capable of doing high efficiency, aerosol sampling (the cutoff diameters are around 0.7 μm for both samplers), and have proven to provide acceptable survival for the collected bioaerosols. By using an appropriate non-aqueous collection liquid, these two personal bioaerosol samplers should be able to permit continuous, long-period bioaerosol sampling with considerable viability for the captured bioae...

The distribution of Staphylococci in bioaerosols from red-meat abattoirs.

Abstract: The quality and shelf-life of perishable foodstuffs can be reduced by high concentrations in the processing environment of bioaerosols consisting of spoilage microbiota. A lack of documented literature on the distribution of such bioaerosols has, however, led to the underestimation of their impact. In the study reported here, the deboning rooms of selected South African red-meat abattoirs were investigated for airborne concentrations of staphylococci; the authors studied the distribution of Staphylococcus species in general, as well as the coagulase types of Staphylococcus aureus in particular. Average staphylococci bioaerosol concentrations varied considerably among the abattoirs investigated, with Abattoir B having the highest counts (3 x 10(2) CFUs/m3) and Abattoir A having the lowest (7.6 CFUs/m3). There was a significant link between bioaerosols and microbial loads from red meat in the same environment. The recorded levels were, however, well below the recommended maximum limits for bioaerosols suggested by various international and governmental authorities. Staphylococcus xylosus and S. saprophyticus were found to be the most abundant species in the air of the deboning rooms, while among S. aureus coagulase types, Type III and Type VIII were predominant. On the basis of the ecology of the bacterial groups, the authors suggest probable sources of staphylococcal bioaerosols and propose strategies that could be developed for red-meat abattoirs to reduce the levels of airborne pathogens.

Sierra Nevada sweep: metagenomic measurements of bioaerosols vertically distributed across the troposphere.

Abstract: To explore how airborne microbial patterns change with height above the Earth’s surface, we flew NASA’s C-20A aircraft on two consecutive days in June 2018 along identical flight paths over the US Sierra Nevada mountain range at four different altitudes ranging from 10,000 ft to 40,000 ft. Bioaerosols were analyzed by metagenomic DNA sequencing and traditional culturing methods to characterize the composition and diversity of atmospheric samples compared to experimental controls. The relative abundance of taxa changed significantly at each altitude sampled, and the diversity profile shifted across the two sampling days, revealing a regional atmospheric microbiome that is dynamically changing. The most proportionally abundant microbial genera were Mycobacterium and Achromobacter at 10,000 ft; Stenotrophomonas and Achromobacter at 20,000 ft; Delftia and Pseudoperonospora at 30,000 ft; and Alcaligenes and Penicillium at 40,000 ft. Culture-based detections also identified viable Bacillus zhangzhouensis, Bacillus pumilus, and Bacillus spp. in the upper troposphere. To estimate bioaerosol dispersal, we developed a human exposure likelihood model (7-day forecast) using general aerosol characteristics and measured meteorological conditions. By coupling metagenomics to a predictive atmospheric model, we aim to set the stage for field campaigns that monitor global bioaerosol emissions and impacts.

Improvement of the air quality in student health centers with chlorine dioxide

Abstract: This study aims to monitor bioaerosol levels of a local campus of a student health center in Taiwan and then to perform disinfection by applying chlorine dioxide. First, air samples were taken and evaluated in the six areas of the center. The average background bioaerosol levels were 714 +/- 1706 CFU/m(3) for bacterium and 802 +/- 633 CFU/m(3) for fungi. Then, chlorine dioxide was applied through three different procedures: single, multiple and regular disinfections. The results indicated that both multiple and regular disinfections can achieve efficiency levels higher than 59.0%. The regression analysis on bioaerosol levels showed that the number of people present correlating to the number of persons entering the room per door-opening, had a correlation of p < 0.05. Utilizing this analysis result, an empirical model was developed to predict indoor bioaerosol concentrations. It can be inferred that for indoor human activity of health centers, regular disinfection is a very effective process.