Bioaerosol

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

Airborne peptidoglycans as a supporting indicator of bacterial contamination in a metal processing plant.

Abstract: OBJECTIVES The aim of this study was to assess exposure to airborne endotoxins and peptidoglycans (PGs) as well as possibility of using PGs as a surrogate measure of bacterial exposure in workplaces in a metal processing plant. MATERIAL AND METHODS Personal dosimetry (N = 11) was used to obtain data on concentrations of viable bacteria, total number of bioaerosol particles, endotoxins and peptidoglycans. To investigate the size distributions of aerosol particles responsible for transport of endotoxins and PGs, air samples (N = 5) were additionally collected using the 8-stage cascade impactor. Endotoxins and PGs were assayed with the Limulus amebocyte lysate (LAL) test and a kinetic version of the silkworm larvae plasma (SLP) test, respectively. RESULTS Median concentrations of airborne PGs (14.6 ng/m3), endotoxins (0.2 ng/m3), viable bacteria (1.16×103 CFU/m3) and the total number of bioaerosol particles (1.81×106 cells/m3) were determined. Qualitative analysis revealed presence of 19 bacterial species belonging to 14 genera. The calculations showed strong, significant correlations (p < 0.05) between endotoxins, viable bacteria (r = 0.75) and the total number of bioaerosol particle concentrations (r = 0.76) as well as between PGs and the total number of bioaerosol particle concentrations (r = 0.72). Size distribution analysis showed that the highest concentrations of bacterial aerosols occurred in the range of 2.1-3.3 μm. In the case of endotoxins, an increase of concentrations in 2 ranges of aerodynamic diameters: 1.1-3.3 μm and 5.8-9 μm was shown. For PGs there was a visible gradual increase of their concentrations in the range 2.1-9 μm. CONCLUSIONS Peptidoglycans can be treated as a supporting indicator of bacterial contamination in metal processing plants, particularly when an assessment of an immunotoxic potential of microbiological hazards needs to be performed. However, to be extrapolated to other occupational and non-occupational environments, the obtained results require a further verification.

Bio-aerosols concentrations in different wards of Khorramabad Hospital, Iran, 2013

Abstract: Aims: This study was conducted to investigate the indoor and outdoor air quality at Ashayer Hospital in Khorramabad, Lorestan, Iran, from May-August 2013. Materials and Methods: Air samples were collected using the ZEFON pump (ZEFON factory, USA) based on manufacturer instructions. Bacteria were isolated via differential methods. Diagnosis of fungi was performed based on amount of fungal colonies growth, shapes, colors, pigments, and microscopic procedure. The effects of various environmental factors including temperature, humidity and outdoor bioaerosol levels were also investigated. Results: Staphylococcus spp. were the most predominant isolated bacteria from studied wards. Furthermore, other microorganisms including Streptococcus spp. Corynebacterium spp., and Micrococcus spp. were also isolated from the hospital air. Moreover, the most frequent fungus in indoor environments of hospital was Penicillium spp., while Aspergillusspp. and Alternaria spp. were the next frequent ones. In addition, the most frequent fungi in adjacent outdoors were Penicillium spp., Aspergillus spp., and Cladosporium spp., respectively. No significant difference was found between the mean concentrations of bioaerosols in inside and outside of hospital (P > 0.05). Conclusion: This study suggests that the bioaerosols level in the hospitals were relatively high. Thus, hospitals should enhance practice of good sanitation protocols and infection control measures.

Response of bioaerosol cells to photocatalytic inactivation with ZnO and TiO2 impregnated onto Perlite and Poraver carriers.

Abstract: Bioaerosols are airborne microorganisms that cause infectious sickness, respiratory and chronic health issues. They have become a latent threat, particularly in indoor environment. Photocatalysis is a promising process to inactivate completely bioaerosols from air. However, in systems treating a continuous air flow, catalysts can be partially lost in the gaseous effluent. To avoid such phenomenon, supporting materials can be used to fix catalysts. In the present work, four photocatalytic systems using Perlite or Poraver glass beads impregnated with ZnO or TiO2 were tested. The inactivation mechanism of bioaerosols and the cytotoxic effect of the catalysts to bioaerosols were studied. The plug flow photocatalytic reactor treated a bioaerosol flow of 460 × 1 06 cells/m3air with a residence time of 5.7 s. Flow Cytometry (FC) was used to quantify and characterize bioaerosols in terms of dead, injured and live cells. The most efficient system was ZnO/Perlite with 72% inactivation of bioaerosols, maintaining such inactivation during 7.5 h due to the higher water retention capacity of Perlite (2.8 mL/gPerlite) in comparison with Poraver (1.5 mL/gPerlite). However, a global balance showed that TiO2/Poraver system triggered the highest level of cytotoxicity to bioaerosols retained on the support after 96 h with 95% of dead cells. SEM and FC analyses showed that the mechanism of inactivation with ZnO was based on membrane damage, morphological cell changes and cell lysis; whereas only membrane damage and cell lysis were involved with TiO2. Overall, results highlighted that photocatalytic technologies can completely inactivate bioaerosols in indoor environments.

Personal exposure to microbial aerosols

Abstract: At present very little is known about total exposures to bioaerosols. Short-time stationary samples correlate poorly with the health effects and probably represent, at best, only surrogates of the true exposure, because during a single day, an individual will be exposed to different concentrations of bioaerosols in several environments. It is necessary to understand better this phenomenon if we are to pinpoint determinants and find associations between exposure and health effects. A random sample of 81 teachers was selected from 823 teachers working in two municipalities in Eastern Finland for the wintertime measurement period (1998 1999). Bioaerosol and other particles were collected on filters using personal sampling and microenvironmental measurements in homes and at work. Particle mass, black smoke, viable and total microorganisms were analysed from each filter. The 24-hour sampling period was repeated twice. Questionnaires of home and workplace characteristics and events during the sampling period were filled in after the measurements. The homes and working places were also inspected for visible signs of moisture by a civil engineer. The personal particle mass (57 g/m), total fungi (12200 spores/m) and viable fungi (33 cfu/m) mean concentrations were higher than home (17 g/m, 10800 spores/m and 30 cfu/m) or workplace (34 g/m, 12000 spores/m and 19 cfu/m) concentrations. Personal (1.10x10 1/m) and work (1.12x10 1/m) BS concentrations were higher than the home (0.67x10 1/m) concentration. Total and viable bacteria concentrations in workplace (145000 cells/m, 1090 cfu/m) were higher than the personal exposure (86400 cells/m, 715 cfu/m) or home concentrations (60600 cells/m, 338 cfu/m). Personal exposure mass concentrations were only moderately correlated with home or work concentrations (r=0.3, p<0.001) while black smoke concentration of personal and home/work filters showed better correlations (r=0.6-0.7, p<0.001). There was no correlation between personal and home/work fungal concentrations. Those samples with higher viable fungal concentrations also had a higher diversity of fungi than the samples with lower concentrations. The concentration ratio of viable fungi and bacteria counts to total counts of fungi and bacteria was close to 1:100. The estimated mass concentrations of total fungi and bacteria were less than 1% of the total particle mass concentration. Variation in the concentration of Penicillium explained between 25 up to 95 % of the variations of viable fungal concentration in personal exposure, home and workplace environment. There was an association between personal exposure and home concentration of viable fungi and between personal exposure and home and work concentrations of viable bacteria. However, the results also indicate that observation of a certain fungus in a main microenvironment does not necessarily coincide with findings from personal exposure samples. There were several determinants (such as behaviour, traffic or building factors) contributing to personal exposure and increasing home and workplace concentrations of particles and microbes. There were common determinants for both personal exposure and microenvironments such as teaching subjects, condensation on window, ventilation and traffic, which point to the presence of potential pollutant sources in these microenvironments. Personal exposure measurements of bioaerosols in indoor environments are feasible ways to assess the real exposure to bioaerosols. In addition to personal bioaerosol exposure, stationary sampling in main microenvironments is often needed to determine the extent to which the microenvironment influences the measurements of total exposure and to design cost effective strategies to reduce exposure and related health effects.

Environment and climate effect of bioaerosol:A review

Abstract: Bioaerosols are a significant subgroup of atmospheric aerosols and its transport should be related to spread of human,animal and plant disease epidemics.Bioaerosols have indirect effect on the alteration of the global climate and atmospheric process.International bioaerosol research has been developing very rapidly during the last two decades,and the area has received an addi-tional spike of attention.Several types of biological organisms(e.g.,fungi,bacteria,and algae)have been identified as effective cloud condensation nuclei(CCN),being active in cloud.The bioaerosols have potential role in modifying the chemical composition of other organic compounds upon collision or contact,and hence inducing changes in the IN or CCN ability of organics in atmos-phere,and implicating them in the alteration of cloud coverage and hence the global climate.Airborne microorganism also has im-pact on air quality,and most research has focused on the source and monitoring of indoor bioaerosols such as fungi,bacteria and allergens.The sample validity is very important for bioaerosols measurement.Some new and applicable on-line sampling and analy-sis technologies,such as Raman Spectroscopic techniques and Time-of-fight Mass Spectrometer,have been developed to reduce sampling error and improve living efficiency of organisms.The atmospheric bioaerosols can be transported for a long range follow-ing some routines,and the temporal and spatial distribution is dependent on the kind of bioaerosol.The recent studies on environ-ment effect,sampling,analysis,distribution and transportation of bioaerosols are reviewed.