Bioaerosols

1. Matt Tribby ENV 6131 Aerosol Mechanics March 29, 2012 Bioaerosols http://en.wikipedia.org/wiki/Sneeze

2. Overview • History • Definition and classifications • Health effects • Transmission • Bioaerosol as weapons • Sampling methods • Protection Methods

3. Definition of Bioaerosol • An aerosol of biological origin, including viruses, viable organisms such as bacteria and fungi and products of organisms such as fungal spores and pollen (Hinds pg. 4) • Emphasis usually given on viability of bioaerosol

4. Bioaerosols In History • Irish Potato Famine (1845-1852) • Roughly 1 million people died due to starvation • Another 2 million emigrated from Ireland • At time of famine 1/3 of population was entirely dependent on potatoes for food • Phytophthora infestans fungus contributed to death of potato crop • Brought in from ships and distributed via wind http://aerosol.ees.ufl.edu/Bioaerosol/Section05.html

5. Bioaerosols In History • Bubonic Plague (Black Death) (1348-1350) • Estimated to have killed 30-60% of Europe’s population • Reduced world’s population from 450 million to around 375 million • Disease originated from fleas and was carried by rats • Yersinia pestis bacteria was cause of disease http://en.wikipedia.org/wiki/File:Blackdeath2.gif http://aerosol.ees.ufl.edu/Bioaerosol/Section06.html Why was the Black Death able to travel through Europe so quickly?

6. Bioaerosols In History • Influenza Epidemic of 1918 • Estimated to have killed nearly 50 - 100 million people • Afflicted more than 25% of the US population • Average life expectancy in US dropped by 12 years • 3% of the global population died, with nearly 500 million (27% global population) being infected What are some diseases associated with bioaerosols in present day? http://www.archives.gov/exhibits/influenza-epidemic/

7. Bioaerosols as weapons • Capable of being used for biological warfare • Growing concern for uses from terrorist groups • Anthrax scare in US in 2001 example http://news.bbc.co.uk/2/hi/americas/1590903.stm Why are bioaerosols as biological weapons more dangerous in present day compared to 100 years ago? http://www.ph.ucla.edu/epi/bioter/detect/antdetect_intro.html

8. Classifications • Microorganisms • Prokaryotes • Eukaryotes • Fungi • Viruses http://www.kimkinservik.com/category/real-estate/

9. Microorganisms - Prokaryotes • One of the simplest living organisms • Lack a nucleus • Most prevalent form is bacterium • Size range from 0.3 – 100 µm • Concentrations of 0.5 – 1000 airborne bacteria per cubic meter of ambient air • Some forms release spores which can survive for long periods of time

10. Prokaryote Diagram

11. Microorganisms - Eukaryotes • Exist as microorganisms such as fungi and protozoa, and highly complex organisms such as plants and animals • DNA located in the nucleus • Contain extra organelles • Mitochondria – animals • Chloroplasts – plants

12. Eukaryote Diagram

13. Fungi • Eukaryotic, non-vascular microorganisms • Reproduce via spores, usually dependent on wind dispersion • Both sexual (meiotic) and asexual (mitotic) spores can be produced • Have alternation of generations Can you name any foods made with fungi?

14. Fungi Diagram http://www.amergeo.com/Papers/Fungus.htm

15. Viruses • DNA strand inside of a protein capsule • Not self-sustaining entities • Require a host to survive and are not able to carry out metabolic processes • Very small size range (20-300 nm) • Small size makes difficult to sample and deep penetration into respiratory tract Why can’t viruses be treated with antibiotics?

16. Virus Diagram http://www.csa.com/discoveryguides/avian/review2.php

17. Health Effects • Can produce a wide range of effects • Bioaerosols have to be viable in order to be infectious • Non-viable can cause allergies or toxic reactions • Allergies estimated cost economy nearly $7 billion annually • Estimated 30.2 million people in United States have been diagnosed with asthma

18. Non-Viable Example: Gulf Coast • Red Tide Blooms in Gulf Coast cause many allergic reactions each year • Algae release toxins due to energy from waves – released as non-viable aerosols • Cause extreme eye and respiratory irritation • Respiratory tract can constrict when in contact with toxins, causes difficulties in breathing http://start1.org/red-tide/

19. Diseases associated with Bioaerosols

20. Transmissions Methods • Methods vary depending on the type of bioaerosol • Dependent on viability • Transferred through natural methods • Wind, Oceans • Transferred through interactions • People, Animals

21. Pathogenic Transmission • Occurs through several routes • Person to person • Waterborne • Foodborne • Vector-borne • Airborne • Combination of the above Can you name a disease that incorporates a combination of the above routes? How can our body’s defense mechanisms actually cause additional harm?

22. Indoor Dangers • Many sources to bioaerosols found indoors • Dust • Pets • Organic Wastes • Building’s circulation of air also can contribute to contamination on multiple floors http://aerosol.ees.ufl.edu/Bioaerosol/Section07.html

23. Air Circulation Dangers • Buildings that rely on re-circulated air pose large threat • Ductwork within buildings can provide moist environment and protection from natural inactivation methods Any areas in a home or building that may have higher concentrations of bioaerosols than others? http://www.homeairlv.com/air-conditioning/air-conditioning-duct-work/

24. Sampling Methods • Sampling method needs to be efficient in three categories • Inlet efficiency • Physical collection • Biological collection • Population can be classified through multiple methods • Mass conc., Number conc. • Viability of bioaerosol crucial in determining the infectivity

25. Sampling Methods • Viable bacteria and fungal spores form colonies (CFU) • Viable viruses form plaques on their host cells (PFU) • Preserving the viable count is needed to maintain high biological collection efficiency What is another aspect to sampling that must be considered when dealing with viability?

26. Impaction • Utilize bioaerosol inertia to collect onto a solid or semi-solid collection medium • If inertia too large then it will not follow air flow lines • Once collected can be cultivated to determine viable count • Physical collection highly dependent on particle size

27. Types of Impaction • Slit impactors • Impact particles directly onto culture medium • Agar is collection medium for bacteria and fungal spores • Agar is semisolid material containing water and nutrients that allow growth • Cell or tissue media used for collection of viruses Why aren’t viruses collected on agar media only?

28. Types of Impaction • Multijet impators • Typically have 100-500 jets impacting directly onto agar culture plates • Spreads collected particles to many locations to prevent overload • Single and multistage available with cutoff diameters from 0.6 – 8 µm • Site with a colony known as filled site or positive hole • Plates analyzed by counting number of filled sites What could be a potential problem associated with this method of collection?

29. 0.483 for f < 0.95 nf = number of filled sites with colonies f = fraction of sites with colonies (nf/Nj) nc = total number of viable organisms collected

30. Can a trend be associated with the correction factors?

31. Impingers • Use liquid media for collection • Inertia used to physically collect bioaerosols along with diffusion http://aerosol.ees.ufl.edu/Bioaerosol/Section09-3_answer.html#93 Would an impactor or impinger be more appropriate for airborne virus sampling?

32. Filters • Use inertia and diffusion for collection of bioaerosols • Have high physical collection efficiency for a wide range of particle sizes • Challenges with extraction How can filters be summarized in regards to efficiencies?

33. Sampling Time • Need to contain a suitable number when collecting viable bioaerosols • Surface density of one colony per cm2 is usual goal • Times can vary depending on the environment of collection

34. Sampling Time calculation

35. How long should an outdoor aerosol sampling time be if the aerosol flow rate is 28 L/min, an average number concentration of bioaerosol particles of 150 CFU/m3 and the area of the collection media is 75 cm2? How does the sampling time change when the environment is changed to an indoor livestock structure with an average number concentration of bioaerosol particles of 105 CFU/m3?

36. http://water.me.vccs.edu/courses/ENV195Micro/lesson7_5.htm http://water.me.vccs.edu/courses/env108/lesson9.htm What is the problem between the two petri dishes?

37. Other Quantifying Methods • Real-time polymerase chain reaction (RT-PCR/qPCR) • Used to amplify and quantify a targeted DNA molecule • Allows detection and quantification for one or more specific sequences in a DNA sample http://www.langfordvets.co.uk/lab_pcr_mdu.htm

38. Protection Methods • Classified as either personal or collective • Personal – individual • Collective – large scale • Respirators used for personal protection • Self-contained breathing apparatus (SCBA) • Gloves, hand-washing and changing of clothes • Antibiotics for bacteria, vaccinations for viruses • UV units added to central air systems • Filtration and electrostatic precipitators (ESPs) used in central air to prevent distribution Would the mass distribution of the influenza vaccine be a personal or collective protection?

39. Research • Determining the viability of influenza bioaerosols with different parameters • Relative Humidity • Absolute Humidity • Temperature • Effects of collection methods on viability of bioaerosols

40. Facts of Influenza • Typical size range of 80 – 120 nm • Many variations • H1N1 • H5N1 • Research has shown that virus most viable in low temperature, low relative humidity environments What season would influenza tend to have the most outbreaks?

41. Facts of Influenza • Still a lot of uncertainty as to viability and contraction of disease in aerosol form • Some studies contradict traditional thoughts • More research is needed to fully understand influenza’s effects on people determined by varying environmental conditions

42. Tamerius et al (2011)

43. Summary • Bioaerosols are aerosols of biological origin • Bacteria • Virus • Pollen • Many health effects can be seen from interactions with bioaerosols • History has shown that some bioaerosols can be global killers • Different sampling methods used for collection • Contamination and viability given focus • Still a lot unknown about characteristics

44. Reflections