Impact of air pollution on farm animal's production and health: aerosols in the barn Flashcards
Airborne particles
- material from organic and inorganic sources incl. minerals, ash, undigested feed, cellular compounds of gut epithelium, grain mites, dried dung, skin, feather dander, collection of microorganisms, their cellular components and metabolic products
- global continuous air pollution control stations are available
- results shows high variability of concentrations in each country/region
- strong and direct connection between small pm conc. of air and incidences of cardiopulmonary diseases and lung cancer
- sedimentation dust and location of their deposition in the resp. tract depends on their size referred as aerodynamic diameter (pm)
Airborne aerosols
- materials finely divided and suspended in air or other gaseous environment
- particles: broad range of sizes, from nanometers to hundreds of micrometers
- may be radioactive or not
- their behavior varies in the atmosphere, indoors, and esp. in the lung
- effects on living organisms are determined by exposure-dose-response relationship
Bioaerosols
- aerobiology: study of biological particles present in the air, research area focusing on the generation and transport of bioaerosols
- bioaerosols: small, airborne particles consisting of biological material may affect living organisms
- in barns: produced by animals, feeds, bedding and manure
- risk of contamination of foods, pharmaceutical products esp. vaccines
- long distance dispersal and transportation by wind, spreading of microbes
- Emission and dispersion of bio-aerosols are frequently liberated from manure storage facilities on live stock farms and mean threat on both animal and human health as well
- biological dust: forms larger aggregates, odorants or ammonia can be bound
Detection of bioaerosols
- no single sampling protocolis available for monitoring of all bioaerosols in their diverse environment
- alternative strategies
- air samplers
- main types of samplers
Detection of bioaerosols
Alternative strategies
- specified reference sampler
- set performance standards
Detection of bioaerosols
Air samplers
◦ Wide range of sampler types
◦ Modified dust or particle samplers
◦ Designed specifically for microbes
◦ Designed specifically for non-microbial bioaerosols (e.g.endotoxin)
◦ Samplers used for microbe collection are adaptable
Detection of bioaerosols
Main types of samplers
a) Gravitational samplers
b) Inertial Bioaerosol Samplers
‣ Spore Traps
‣ Impactors
‣ Impingers
‣ Cyclones (centrifugal) Samplers ‣ Large Volume Aerosol Samplers
c) Non-Inertial Samplers
‣ Filtration Samplers
‣ Electrostatic Precipitation
‣ Thermal Precipitation and Condensation Traps
Impingers
- Particles removed by air drawn through liquid (e.g.water, broth, mineral oil),
- Dilution is possible
- Problems with pass through, particle bounce, bubbling, evaporation of liquid loss of viability
- Inlet efficiency decreased for particles above 10microns
Impactors
• Collection on slide or agar plates
• Several designs tend to undersample smaller particles; particle bounce can also be an issue
• Used at airflows of 10-30L/min
• Types:
◦ Single Stage or Multistage (e.g. Anderson)
◦ Rotary arm samplers (e.g. Rotorod, Mesosystems BT550)
◦ Slit to agar samplers system.
◦ Sieve Samplers and Stacked Sieves (e.g.SAS)
Filtration
- Simple and cheap method
- Devices are simple and easily adoptable to specific purpose
- Wide variety of filters are available
- Wide range of aimed particle size
- Desiccation of trapped microorganisms is a serious limitation – gel filters may help in Elongation of sampling time
Microbiological examination
• Traditional cultivation procedure
• Old DNA sequencing technique used the Sanger method, which is labor intensive, expensive, and slow
• Next generation sequencing by synthesis methods has revolutionized the research:
◦ Ribosomal RNA (rDNA) encoding gene sequencing
◦ Metagenomic, metatranscriptomic sequencing
◦ Next Generation Sequencing (NGS) methods
◦ Quantitative PCR
◦ Illumina Next Seq, MiSeq, MiniSeq, HiSeq sequencing of ITS1 region
◦ ThermoFischerScientific Ion S5
◦ Single-cellRNA-seq (SMRT) realtimere ading
• The generated big data mass is a new challange–special knowledge and sofwares are needed
The Air from Veterinary Epidemiologic Point of View
- atmosphere plays a fundamental role in transport of microbes across the planet
- global estimate of microbial loads and air-sea exchanges over the tropical and subtropical oceans
- Microbes may be transported and deposited over the seas up to thousands of kilometers away from their source
- 3 of the top 6 potentially death-causing infectious disease in the developing world incl. acute resp. infections, tuberculosis, and measles, are linked to airborne pathogens (WHO) underlines the global importance of
Aerobiology
Airborne pathogens caused animal diseases, outbreaks
- viruses and vectors are transported by wind
- FMD, Aujeszky’s disease, Newcastle disease, Avian influenza, Q fever, Strep spp, Mycobacteriom tuberculosis, E.coli, fungal pathogens, disease complexes in association with poor animal hygiene
Predictive, simulation models
- Air Quality Dispersion Modeling
- AERMOD Modeling System
- CALPUFF Modeling System
- ALOHA with CAMEO package (Aujeszky’s disease modeling)
- additional veterinary microbiological tests and methods: qPCR, quantitative microbial risk assessment (QMRA)
