Bioaerosols In Air Research Articles

Study on the concentration, composition, and recovery rate of bacterial bioaerosols after rainfall in Ho Chi Minh City.

Aerosolized microorganisms have become an important factor in assessing air quality. To determine the characteristics of bacterial bioaerosols in air and rainwater, as well as calculate the recovery rate of bacteria after rains in Ho Chi Minh City, our study was performed using the SKC Biostage sampler for airborne bacteria and Plate Count Agar (PCA) medium for bacterial concentration. Subsequently, the study determined the bacterial community composition at the phylum and order levels using the 16S rRNA (16S metabarcoding) method. Before the rain, bacterial concentrations in the air ranged from 263.39 ± 21.00 to 277.39 ± 78.99CFU/m3, and in rainwater 264.89 ± 51.17 to 285.72 ± 28.00CFU/m3. Following rains, the bacterial concentrations decreased to their lowest levels within the first 1-2h and gradually increased thereafter, reaching their peak after 9h for heavy rain and after 12h for light and moderate rains. The bacterial bioaerosols recovery rate was determined to be 100% for light and moderate rains and 94.6% for heavy rain. The change in bacterial concentration after rainfall showed a positive correlation with temperature (r = 0.85) and CO2 concentration (r = 0.70) and a negative correlation with relative humidity (r = - 0.79). Bacterial composition analysis revealed that the Actinobacteria, Firmicutes, and Proteobacteria phyla were dominant and characteristic of the humid tropical climate in Vietnam. Notably, Firmicutes were the most prevalent phylum both before and after rains. The increased prevalence of certain bacterial orders, particularly Staphylococcus, could contribute to the spread of pathogens, particularly foodborne pathogens. In addition to rain, relative humidity contributed to reducing bacterial bioaerosols concentration and their recovery rate after the rain.

Decrease of bioaerosols in westerlies from Chinese coast to the northwestern Pacific: Case data comparisons

The dissemination of bioaerosols in the westerly wind from the Asian continent to the northwestern Pacific constantly links the land and marine ecosystems. Several observation campaigns targeting bioaerosols were conducted in the coastal city Qingdao of China (QD), at a coast site of Kumamoto in southwestern Japan (KM), and in the northwestern Pacific (NP) between 2014 and 2016. We compared the concentration of bioaerosols in the range of 1.1–7.0 μm obtained in those campaigns to investigate their variation in the westerly wind. The substantial influence of westerlies on bioaerosol concentration was confirmed in the three areas. In the case of non-dust air, the arrival of the continental air led to a 29 % decrease of bioaerosols at KM while a 57 % increase at NP, indicating that the concentration in non-dust air was lower than the local level in the island air while higher than that in the remote marine air. In case of dust occurrence, bioaerosols in the air decreased with the distance from the Asian continent at KM and NP consecutively, and the arrival of the air caused a 2-fold increase at KM and a 1.7-fold increase at NP. The relative concentration increase rate of bioaerosols (IRRC), defined as the ratio of the increment of bioaerosols caused by long-distance transported air to the local level in each area, decreased rapidly after the air left the continent in the dust cases, which is similar to the decrease of the dry deposition flux of dust reported in the literature. This result indicates that the reduction of bioaerosols in the dusty air was likely dominated by the removal of bioaerosols attached to dust particles.

Why should we care about high temporal resolution monitoring of bioaerosols in ambient air?

This is the first time that atmospheric concentrations of individual pollen types have been recorded by an automatic sampler with 1-hour and sub-hourly resolution (i.e. 1-minute and 1-second data). The data were collected by traditional Hirst type methods and state-of the art Rapid-E real-time bioaerosol detector. Airborne pollen data from 7 taxa, i.e. Acer negundo, Ambrosia, Broussonetia papyrifera, Cupressales (Taxaceae and Cupressaceae families), Platanus, Salix and Ulmus, were collected during the 2019 pollen season in Novi Sad, Serbia. Pollen data with daily, hourly and sub-hourly temporal resolution were analysed in terms of their temporal variability. The impact of turbulence kinetic energy (TKE) on pollen cloud homogeneity was investigated. Variations in Seasonal Pollen Integrals produced by Hirst and Rapid-E show that scaling factors are required to make data comparable. Daily average and hourly measurements recorded by the Rapid-E and Hirst were highly correlated and so examining Rapid-E measurements with sub-hourly resolution is assumed meaningful from the perspective of identification accuracy. Sub-hourly data provided an insight into the heterogenous nature of pollen in the air, with distinct peaks lasting ~5–10 min, and mostly single pollen grains recorded per second. Short term variations in 1-minute pollen concentrations could not be wholly explained by TKE. The new generation of automatic devices has the potential to increase our understanding of the distribution of bioaerosols in the air, provide insights into biological processes such as pollen release and dispersal mechanisms, and have the potential for us to conduct investigations into dose-response relationships and personal exposure to aeroallergens.

The investigation of type and concentration of bio-aerosols in the air of surgical rooms: A case study in Shariati hospital, Karaj

The presence of bio-aerosols is one of the main causes of hospital infections that can be dangerous especially for immunocompromised patients. This research aimed to determine the relationship between hospital infections and surgical incision size in addition to determining the concentration and bacterial and fungal bioaerosols found in the operating rooms. This cross-sectional descriptive-analytic study was carried out in the operating rooms of Shariati Hospital in Karaj, Iran during the years 2016 and 2017. A total of 198 bacterial samples and 198 fungal samples were collected and analyzed using a passive sampling standard method (1/1/1) for 180 days. Tryptic Soy Agar (TSA) and Sabouraud Dextrose Agar (SDA) medium were used for bacterial and fungal samples, respectively. Relevant differential tests were used to determine the genus and species of bacteria and fungi such as DNase test, Bile-esculin, motility test urease test. In general, this work presents:•The present evaluated the relationship between bioaerosols concentration and surgical incision size.•The intraoperative concentration of bacterial and fungal bioaerosols in indoor air of the orthopedic, internal and cesarean operating rooms was significantly higher than their preoperative concentration (p-value<0.05).•Also, there was not significant difference between the bacterial and fungal concentrations in various operating rooms) p-value<0.05).

Microbiological characteristics of indoor air bioaerosols in a waste paper recycling factory

There has been an increasing interest among occupational hygienists and public health officials in indoor air quality assessment in industrial workplace environments. Exposure to bioaerosols may pose health risks to workers operating in the processing of recycled waste paper. This study was conducted in two waste paper recycling factories. Air sampling of the factory was performed on weekly basis over a period of 3 months employing passive air sampling technique (the settle plates) with standard Petri dishes in which appropriate culture media are used for counting bacteria and fungi in air samples. In addition, metagenome analyses were conducted to obtain more details about the diversity and abundance of bacteria in the investigated factory. Results showed abundant bacterial and fungal counts in the waste paper factory in all the manufacturing stages. In particular, the cutting/shredding unit exhibited high microbiological contamination; thus, corrective measures should be taken in order to achieve better indoor air quality. The most dominant genus detected according to both DGGE sequencing and metagenome analysis was Thermicanus. The dominance of this thermophilic, microaerophilic fermentative species especially during summer season reflects the condition within the factory as well as the source of the recycled paper and the way it has been handled and stored. An air flow ventilation system that prevents contamination from areas where raw waste paper is handled is recommended.

DEFINITION OF THE OPTIMUM MODES OF OPERATION OF AIR-MONITORING.INSTRUMENTATION FOR DETECTION OF PATHOGENIC BIOLOGICAL AGENTS IN MODEL EXPERIMENTS

To experimentally define the optimum modes ofoperation ofthe nonspecific detector IBAC integrated with C100 sampler and BioCapture sampler in model experiments during the work in various environmental conditions and at dispersion of the biological aerosol. The nonspecific detector IBAC with the C100 sampler and the BioCapture sampler were used for air-monitoring test on existence of pathogenic biological agents (PBA). For preparation of the bioaerosols the strain of Salmonella typhimurium 9640 and a bull seralbumin were used. It is experimentally established that programming of IBAC on turning on the bioalarm system when maintaining concentration of bioaerosol in air above threshold level during 10 sec. is optimum. Its sensitivity makes 1x10³ m.c./ml of aerosol at this mode. The possibility of operation of air-monitoring instrumentation in various environmental conditions inside and outside is shown. As a result of the experi- ment the effectiveness of usage of the nonspecific detector IBAC with the C100 sampler and BioCapture sampler for air-monitoring on existence of PBA is proved. IBAC with C100 can be used as an inventory ofthe station ofair-monitoring during the public events, and BioCapture is suitable for equipment of the groups of epidemiological investigation.

Sensory Evaluation Spectrum Method as a Descriptive Sensory Analysis

Sensory evaluation is used to measure consciousness, and primarily developed in experimental and mathematical psychology. Sensory experiences can be reported using verbal (semantic) methods. This paper presents an overview of our semantic research achievements over the past decade, focusing on methodological attempts for substantiating the measure as a descriptive sensory analysis. Two types of studies that deserve particular attention are detailed: 1) evaluation of the efficacy of photo catalytic elimination of stains or bio-aerosols in air using TiO2 and photo catalytic deodorizing properties of a TiO2-type deodorizer; and 2) evaluation of the differential discrimination of perceived odor quality for a given aroma while inhaling the fragrances of essential oils. Both studies are based on semantic responses of participants. The perceived sensory attributes in the participants can be represented by a sensory spectrum: a bar graph whereby the mean of the impressions is plotted against the setting semantic impression descriptors. In the former study, we provide a background on the sensory evaluation spectrum method and discuss its implementation as a measure of descriptive sensory analysis. The latter study additionally demonstrates how statistical defects were overcome when spectra were not statistically significant.

A Synthesized TiO2 Coated Sieve in a Photocatalytic Reactor for Deactivating Bioaerosol in Air

A Synthesized TiO2 Coated Sieve in a Photocatalytic Reactor for Deactivating Bioaerosol in Air

The microbial signature of aerosols produced during the thermophilic phase of composting

The microbial diversity of bioaerosols released during operational activities at composting plants is poorly understood. Identification of bacteria and fungi present in such aerosols is the prerequisite for the definition of microbial indicators that could be used in dispersal and exposure studies. A culture-independent analysis of composting bioaerosols collected at five different industrial open sites during the turning of composting piles in fermentation was performed by building 16S rDNA and 18S rDNA libraries. More than 800 sequences were analysed. Although differences in the phylotypes distribution were observed from one composting site to another, similarities in the structure of microbial diversity were remarkable. The same phyla dominated in the five bioaerosols: Ascomycota among fungi, Firmicutes and Actinobacteria among bacteria. For each phylum, some dominant phylotypes were common to at least four bioaerosols. These common phylotypes belonged to Thermomyces, Aspergillus, Penicillium, Geobacillus, Planifilum, Thermoactinomyces, Saccharopolyspora, Thermobifida and Saccharomonospora. The microbial signature of aerosols produced during the thermophilic phase of composting was determined. The similarities observed may be explained by the selection of thermophilic and sporulating species. Several bacteria and fungi identified in this study may represent potential indicators of composting bioaerosols in air.

The Study of Ambient Air Bioaerosols During Summer Daytime and Nighttime Periods in Taichung, Central Taiwan

Suspended particles, of which bioaerosols are one type, constitute one of the main reasons for poor air quality in Taiwan. Bioaerosols include allergens such as fungi, bacteria, actinomycetes, arthropods, and protozoa, as well as microbial products such as mycotoxins, endotoxins, and glucans. When allergens and microbial products are suspended in the air, local air quality will be influenced severely. When the particle size is small enough to pass through the respiratory tract entering the human body, the health of the local population is threatened. Therefore, the purpose of this study was to understand the concentration and types of bacteria during the summer period at four sampling sites in Taichung, central Taiwan. The total average bacterial concentrations at 48-h incubation time during the summer daytime period were 8.1 × 102, 1.9 × 103, 3.7 × 10 3, and 1.1 × 103 cfu/m3 and nighttime period were 1.1 × 103, 2.6 × 103, 3.2 × 103, and 1.9 × 103 cfu/m3 from June 30 to August 1, 2005. The average bacterial concentration increased as the incubated time increased for each particle size range. The high average bacterial concentration was found in the particle size 0.34–0.71 mm (average bioaerosol size was in the range of 1.1–4.7 μm) for each sampling site. There were more than 20 types of bacteria at each sampling site and the bacteria shapes were rod, coccus, and filamentous.