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A review on bio aerosol science, technology and engineering: current and beyond

A review on bio aerosol science, technology and engineering: current and beyond. Maosheng Yao. College of Environmental Sciences and Engineering Peking University. Outline. Bioaerosol Emissions Air Sampling Techniques Biological Assessment, Detection and Control

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A review on bio aerosol science, technology and engineering: current and beyond

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  1. A review on bioaerosol science, technology and engineering: current and beyond Maosheng Yao College of Environmental Sciences and Engineering Peking University

  2. Outline • Bioaerosol Emissions • Air Sampling Techniques • Biological Assessment, Detection and Control • Current State of Bioaerosol Research

  3. Biological Agents in the Environments • Particles of biological origins --bacteria, fungi, viruses , pollen --their derivatives such as endotoxins, glucans, and mycotoxins --fungal allergens, indoor house dust mites, dog, cat allergens 0.5-2μm for bacteria & 2-5μm for fungi commonly found, viruses are usually below 0.3 μm

  4. Bioaerosol Emissions • Natural environments • Human and animal are sources of bioaerosol • Waste recycling, bio-solid land application, composting, agriculture, pharmaceutical and bio-techactivities • Hospital settings (surgery, organ transplant, and dental treatment) • Bioterrorism events

  5. Why Are We Concerned about These Biological Agents? • Exposure to the biological agents presents a serious health challenge both for public and private sectors • Respiratory diseases such as asthma, pneumonia, and allergies. • Infectious diseases such asSARS, andBird Flu. SARS outbreak in 2003 Influenza (bird flu) Outbreak

  6. Canada USA Australia Brazil Global Asthma Impacts China According to WHO estimates, 300 million people suffer from asthma and 255, 000 people died of asthma in 2005

  7. Pneumonia Death in Children < 5 Years Old WHO estimates that up to 1 million children under 5 die each year from pneumonia.

  8. Annual Impacts of Epidemic Influenza Estimates for the US • Cases:20-50+ millions • Days of illness:100-200 millions • Work & school loss:tens of millions • Hospitalizations:85,000-550,000 • Deaths:34,000-50,000 • Economic loss:billions of dollars MMWR 2003; 52 (RR-8); Thompson et al. JAMA 2003; 289:179 Thompson et al., JAMA 2004; 292:1333; Adams PF et al. Vital Health Stat 1999; 10(200) In addition, infectious diseases took a tremendous toll both on human and economy

  9. Global Outbreak of SARS in 2003

  10. Social Impacts of SARS

  11. Increasing Threat of Bio-terrorism That May Release Lethal Airborne Biological Agents

  12. Bio-Sampling The first critical step for monitoring, assessment, or control strategy for the biological inhalation exposure

  13. Air Sampling Techniques • Impactors • Liquid impingers • Filters • Electrostatic precipitator

  14. Impactors • Andersen six-stage impactor was developed in the 50s and widely used as a standard for bioaerosol sampling • BioStage Impactor (SKC, Inc., Eighty Four, PA) --collect microorganisms onto agar surface --28.3 Liter/min with an impaction velocity of 24m/s BioStage It was used in anthrax investigation

  15. Principle of Collection by Impactor

  16. Portable Microbial Impactors • Becoming more popular for sampling airborne biological agents -- Battery-powered, portable, easy to handle -- High volume sampling, more than 100 L/min

  17. Particle Collection of Portable Samplers

  18. Portable Microbial Impactors Bio-Culture 120 L/min Microflow 120 L/min SMA MicroPortable 28.3/141.5 L/min

  19. Portable Microbial Impactors RCS High Flow 100 L/min SAS Super 180 180L/min Millipore Air Tester 140/180 L/min They have been used in military sites

  20. Portable Microbial Impactors • These samplers are increasingly being used for bio-sampling • Their sampling performances are not fully described or investigated MAS-100 100 L/min Investigation of physical and biological collection efficiencies

  21. Sampler Testing System Yao, M. and Mainelis, G. Aerosol Sci. Technology, 2006, 40:1-13.

  22. Physical Collection Efficiencies & Cutoff Sizes of Seven Portable Microbial Samplers When Sampling PSL Particles Virus anthrax Yao, M. and Mainelis, G. Aerosol Sci. Technology, 2006, 40:1-13.

  23. Comparison of Sampler Performance with Particle Inhalation and Deposition in Human Lung Yao and Mainelis, J. of Exposure Analysis and Env Epi, (2007), 17, 31–38

  24. Biological Collection Efficiency the ability of the sampler to not only collect, but also keep the viability of the bio-particles

  25. Influences of Jet Velocity and Jet-to-plate Distance on Biological Collection Efficiency

  26. Air sampling Techniques Anthrax surrogate • filtration gelatin filter

  27. Air Sampling Techniques • BioSampler 1) Liquid Impinger, use of centrifuge and impaction to collect aerosol particles with a sampling flow rate of 12.5 L/min 2) Longer sampling time up to 8 hours 3) Transferring aerosols into hydrosols BioSampler Powerful aerosol-2-hydrosol sampling techniques are needed

  28. Bio- sampling Challenges • Impaction-based sampling techniques were shown to cause damages to the viability of microorganisms • Virus is too small to be collected by these techniques & their sampling method is significantly lacking • There is a need to develop a more advanced sampling strategy

  29. Electrostatic Collection • Electrostatic collection is a mechanism of collecting the airborne charged particles using the electrical force • Collection velocity is about 2 to 4 orders of magnitude lower than that of BioStage impactor (24 m/s) • Lower mechanical stress and less desiccation upon the microorganisms being sampled

  30. Electrosampler was designed to investigate if natural charges of microorganisms can be used for their effective electrostatic collection Yao and Mainelis, Journal of Aerosol Science, 2006, 37:513-527

  31. Physical Collection Efficiency of Electrosampler Electrostatic field may have the ability to collect viruses Electrostatic field, 5kV/cm, was used

  32. Comparisons of outdoor bacteria sampling using Electrosampler and BioStage impactor Electrostatic method provides a better biological quantification

  33. Use of Electrostatic Field in Collecting Airborne Toxins

  34. Use of Electrostatic Field in Collecting Airborne Allergens

  35. Bioaerosol Detection and Assessment(Combining Physical , Biochemical and Molecular Techniques ) • The electrostatic method demonstrates ability in collecting viruses from the air. • Virus concentration could be very low in the air, even collected, might not be enough to be detected. • Combination of electrostatic method with advanced molecular techniques such as qPCR and ELISA may offer a solution, e.g., for detecting influenza A virus.

  36. Globally confirmed human cases of H5N1 avian influenza since 2003

  37. Influenza A Virus • Commonly known as flu, is an infectious disease of birds and mammals caused by an RNA virus • Typically, influenza is transmitted from infected mammals through the air by coughs or sneezes, creating bioaerosols containing the virus • Currently, the strand is only limited to animals, but it is very likely to mutate further becoming a human-to-human case. Hong Kong Flu (magnified approximately 70,000 times) in May 1997

  38. Spanish Flu in 1918 “In 1918, Spanish flu killed 675,000 people in the U.S. and an estimated 20–50 million people worldwide”

  39. Detection of influenza A Virus Metal Plate Virus particles Air Out Air In E qPCR ELISA Metal Plate Biosensor + 96-well-plate Endotoxin/Glucan Yao et al. (2007) Integration of Technologies for Constant Monitoring of Exposure [E-Letter], Science.

  40. Environmental Allergens • Common Allergens? House dust allergens (Der p 1 and Der f 1), cat allergens Fel d 1 (cat), dog allergen Can f 1 (dog), Bla g 1 (cockroach), Bla g 2 (mouse) fungal allergens, e.g., Alternaria alternata allergen Alt1 • Enzyme-Linked ImmunoSorbent Assay (ELISA) is often used to analyze allergens

  41. ELISA Sample Processing Dissolve into 1.5 mL PBS 0.05% Tween 20 shaking 2 h Dust Sieving (>30 mg) centrifuge 20 min supernatant 96-well plate Antibody coated plate

  42. Procedure of ELISA tests ELISA can be used together with air sampling technique for measuring airborne viruses and allergens

  43. House Dust Mite (Der p & Der f 1)

  44. Principle of LAL/Glucatell Assay(airborne endotoxin and glucan) LAL LAL Activates Endotoxin (LPS) (1,3)-β-D-glucan Factor C Factor G LAL LAL Factor B LAL Preclotting Enzyme LAL SubstrateAc-Ile-Glu-Ala-Arg-pNA. pNA (yellow) Horseshoe crab LAL (Limulus Amoebocyte Lysate)

  45. LAL/Glucatell 分析方法的流程 Add sample extracts, standards into 96 well plate Filter Extraction Dilution (10-3) 0.05% Tween 20 for Endotoxin 0.5 N NaOH for glucan, neutralized by Tris-HCL Incubation (15 min at 37 oC) add LAL or Glucatell Agents Placed inside spectraphotometer Log(Y)=A+Log(X) 60-80 min

  46. Results for Road Dust In collaboration with Lovelace Respiratory Research Laboratory

  47. Results for Road Dust In collaboration with Lovelace Respiratory Research Laboratory

  48. qPCR for quantification of microbial species Primary tasks include: • Selection or design of primer sets for specific microbial species (alternaria spp) • Design of probes for specific allergens & develop standard curves • quantitative-PCR tests for DNA extracts from environmental samples DNA extraction Primers & Probes Standard Curve qPCR tests

  49. qPCR for quantification of microbial species qPCR reaction mixture: Template DNA Forward/Reverse Primers, Probes dNTPs DNA Polymerase Buffer Tris, KCl, Mg2+ ,BAS , etc.

  50. 19 Sample qPCR Application Curves Vesper et al, 2005, American Laboratory, pp. 11-12

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