Bioaerosol

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

Size-Resolved Concentrations of Particulate Matter and Bioaerosols Inside versus Outside of Homes

Abstract: Size-resolved airborne particulate matter samples (PM 2.5 , PM 10 , and TSP) collected inside ten northern California homes over four days and one night (9–12 h/sample, spanning a 3.5 week period) were analyzed for protein, endotoxin, and (1 → 3)-β-D-glucan concentrations. Some simultaneous size-resolved outdoor samples were also collected. The associations of residential characteristics and occupant behavior with the indoor airborne levels were investigated. In addition, the relation between these chemical biomarkers and the more traditional culturing approaches was studied. Most of the indoor mass concentration of airborne particles and protein was in the fine fraction (PM 2.5 ), while the mass of airborne endotoxin and (1 → 3)-β-D-glucan was mainly in the coarser fractions (PM 10–2.5 and PM TSP–10 ). No strong correlations were seen between short-term (3–6 min) culturable bacteria and fungi counts and the corresponding longer-term (9–12 h) biomarker levels. Daytime indoor levels of the biomarkers tende...

Investigation of the Efficiencies of Bioaerosol Samplers for Collecting Aerosolized Bacteria Using a Fluorescent Tracer. I: Effects of Non-sampling Processes on Bacterial Culturability

Abstract: By sampling aerosolized microorganisms, the efficiency of a bioaerosol sampler can be calculated depending on its ability both to collect microorganisms and to preserve their culturability during a sampling process. However, those culturability losses in the non-sampling processes should not be counted toward the sampling efficiency. Prior to the efficiency assessment, this study was designed to investigate the culturability losses in three non-sampling processes: (1) the tracer uranine induced loss; (2) the loss during aerosolization (pre-sampling process); and (3) the bacteria and uranine recovery in air sample handling procedures for the samples of the Andersen 6-stage impactor and the Airport MD8 (post-sampling process). The results indicated that uranine had no significant effect on the culturability of Enterococcus faecalis, Escherichia coli, and Mycoplasma synoviae in suspensions (P > 0.05), but negatively affected the culturability of Campylobacter jejuni (P = 0.01). The culturability of E. faecalis, E. coli, and M. synoviae was not affected by stresses caused by aerosolization (P > 0.05). Only 29% of C. jejuni were still culturable during aerosolization (P = 0.02). In the air sample handling procedures, the four species of bacteria were recovered without significant losses from the samples of the Andersen impactor, but only 33-60% uranine was recovered. E. faecalis, E. coli, and M. synoviae were recovered without significant losses from the samples of the Airport MD8. More C. jejuni was recovered (172%), probably due to multiplication or counting variation. It is suggested that tracer and bacteria should be aerosolized separately when the tracer negatively affects the bacterial culturability. In both pre- and post-sampling processes, losses of bacterial culturability (or multiplication) may occur, which should be taken into account when assessing the efficiencies of bioaerosol samplers.

Microbial Contents of Vacuum Cleaner Bag Dust and Emitted Bioaerosols and Their Implications for Human Exposure Indoors

Abstract: Vacuum cleaners can release large concentrations of particles, both in their exhaust air and from resuspension of settled dust. However, the size, variability, and microbial diversity of these emissions are unknown, despite evidence to suggest they may contribute to allergic responses and infection transmission indoors. This study aimed to evaluate bioaerosol emission from various vacuum cleaners. We sampled the air in an experimental flow tunnel where vacuum cleaners were run, and their airborne emissions were sampled with closed-face cassettes. Dust samples were also collected from the dust bag. Total bacteria, total archaea, Penicillium/Aspergillus, and total Clostridium cluster 1 were quantified with specific quantitative PCR protocols, and emission rates were calculated. Clostridium botulinum and antibiotic resistance genes were detected in each sample using endpoint PCR. Bacterial diversity was also analyzed using denaturing gradient gel electrophoresis (DGGE), image analysis, and band sequencing. We demonstrated that emission of bacteria and molds (Penicillium/Aspergillus) can reach values as high as 1E5 cell equivalents/min and that those emissions are not related to each other. The bag dust bacterial and mold content was also consistent across the vacuums we assessed, reaching up to 1E7 bacterial or mold cell equivalents/g. Antibiotic resistance genes were detected in several samples. No archaea or C. botulinum was detected in any air samples. Diversity analyses showed that most bacteria are from human sources, in keeping with other recent results. These results highlight the potential capability of vacuum cleaners to disseminate appreciable quantities of molds and human-associated bacteria indoors and their role as a source of exposure to bioaerosols.

Diarrhoea among waste collectors associated with bioaerosol exposure

Abstract: Gastrointestinal problems such as diarrhoea have previously been reported in small studies among waste collectors. The present nationwide study relates self-reported diarrhoea symptoms to self-reported working conditions and estimated levels of bioaerosols. A questionnaire based survey among Danish waste collectors (n = 2303) and a comparison group of male municipality workers (n = 1430) collected data on occupational exposures, present and past working environment, psychosocial work environment, and health status. Estimated exposure was related to self-reported working conditions. Prevalence Proportion Ratios (PPR) adjusted for relevant confounders were estimated by generalized linear models. The group with high exposure to fungal spores reported most diarrhoea symptoms (PPR = 5.60 (2.39;13.08)), medium exposure was associated with fewer diarrhoea symptoms (PPR = 3.45 (2.24;5.31)), and the low exposure was associated with the fewest diarrhoea symptoms (PPR = 3.02 (1.86;4.92)). Test for trend was significant. The group with high exposure to either total count of fungi or total count of microorganisms reported fewest symptoms compared to the low exposed. No positive trend was found. This study reported an association between level of exposure to fungal spores and self-reported diarrhoea among waste collectors. Address for correspondence: Ulla I. Ivens, Department of Occupational Medicine, National Institute of Occupational Health, Lersø Parkallé 105, DK-2100 Copenhagen Ø, Denmark. E-mail: uii@ami.dk