Characteristics of Microbial Aerosol Pollution in Pig Houses

[ Objective] To explore the characteristics of microbial aerosol pollution in different pig houses and provide theoretical foundation for risk assessment of microbial aerosols on human and animal health. [Method] Gestation house, nursery house and fattening house in suburb of Beijing were chosen as research objects, and the concentration, size distribution and composition characteristics of the airborne microorganisms were determined. [ Result] The concentrations of airborne microorganisms were completely different in different houses under the influences of ventilation, methods of cleaning manure and pig populations. The highest concentration of airborne microrganisms was the nursery house. The particles with diameter size of 0.65 -2.10 μm carried 26% -27% heterotrophic bacteria and 39% -43% fungi. They could reach alveolus of humans and animals and thus made infectious threat to health of humans and animals. The dominant heterotrophic bacteria genera were composed of Bacil/us and Pseudomonas; and the dominant fungi were Penicillium and Muco. [ Conclusion] Concentrations of airborne microorganisms are completely different in different houses. However. there is no sianificant difference between the microbial composition and tyee of oia houses.

Advances in Electrostatic Plasma Methods for Purification of Airborne Pathogenic Microbial Aerosols:Mechanism,Modeling and Application

The transmission of pathogenic airborne microorganisms significantly impacts public health and societal functioning.Ensuring healthy indoor air quality in public spaces is critical.Among various air purification technologies,electrostatic precipitation and atmospheric pressure nonthermal plasma are notable for their broad-spectrum effectiveness,high efficiency,cost-effectiveness,and safety.This review investigates the primary mechanisms by which these electrostatic methods collect and disinfect pathogenic aerosols.It also delves into recent advancements in enhancing their physical and chemical mechanisms for improve efficiency.Simultaneously,a thorough summary of mathematical models related to the migration and deactivation of pathogenic aerosols in electrostatic purifiers is provided.It will help us to understand the behavior of aerosols in purification systems.Additionally,the review discusses the current research on creating a comprehensive health protection system and addresses the challenges of balancing byproduct control with efficiency.The aim is to establish a foundation for future research and development in electrostatic aerosol purification and develop integrated air purification technologies that are both efficient and safe.

Microbial aerosol particles in four seasons of sanitary landfill site:Molecular approaches,traceability and risk assessment

Landfill sites are regarded as prominent sources of bioaerosols for the surrounding atmosphere.The present study focused on the emission of airborne bacteria and fungi in four seasons of a sanitary landfill site.The main species found in bioaerosols were assayed using high-throughput sequencing.The Source Tracker method was utilized to identify the sources of the bioaerosols present at the boundary of the landfill site.Furthermore,the health consequences of the exposure to bioaerosols were evaluated based on the average daily dose rates.Results showed that the concentrations of airborne bacteria in the operation area(OPA)and the leakage treatment area(LTA)were in the range of(4684±477)–(10883±1395)CFU/m^(3) and(3179±453)–(9051±738)CFU/m^(3),respectively.The average emission levels of fungal aerosols were 4026 CFU/m^(3) for OPA and 1295 CFU/m^(3) for LTA.The landfill site received the maximum bioaerosol load during summer and the minimum during winter.Approximately 41.39%–86.24%of the airborne bacteria had a particle size of 1.1 to 4.7μm,whereas 48.27%–66.45%of the airborne fungi had a particle size of more than 4.7μm.Bacillus sp.,Brevibacillus sp.,and Paenibacillus sp.were abundant in the bacterial population,whereas Penicillium sp.and Aspergillus sp.dominated the fungal population.Bioaerosols released from the working area and treatment of leachate were the two main sources that emerged in the surrounding air of the landfill site boundary.The exposure risks during summer and autumn were higher than those in spring and winter.

Bioaerosol emissions variations in large-scale landfill region and their health risk impacts

Landfills are widely complained about due to the long-term odor and landfill gas emissions for local residents,while the bioaerosols are always neglected as another threat to on-site workers.In this study,bioaerosols samples were collected from the typical operation scenes in the large-scale modern landfill,and the emission levels of airborne bacteria,pathogenic species,and fungi were quantified and co-related.The corresponding exposure risks were assessed based on the average daily dose via inhalation and skin contact.It was found that the levels of culturable bacteria and fungi in all landfill samples were around 33–22778 CFU/m3 and 8–450 CFU/m3,and the active-working landfill area and the covered area were the maximum and minimum emission sources,respectively,meaning that the bioaerosols were mainly released from the areas related with the fresh waste operation.Acinetobacter sp.,Massilia sp.,Methylobacterium-Methylorubrum sp.and Noviherbaspirillum sp.were the main bacterial populations,with a percentage of 42.56%,89.82%,70.24%and 30.20%respectively in total bioaerosols measured.With regards to the health risk,the health risks via inhalation were the main potential risks,with four orders of magnitude higher than that of skin contact.Active-working area showed the critical point for non-carcinogenic risks,with a hazard quotient of 1.68,where 80 m protection distance is recommended for on-site worker protection,plus more careful protection measures.