Respiratory (Air-borne) Diseases Flashcards
What are the 4 gases that make up air?
- nitrogen - 78%
- oxygen - 21%
- argon - 0.9%
- air pollutants - 0.1%
Most respiratory diseases are due to inhaling harmful air pollutants from the air. What are the 3 classes of air pollutants?
- harmful gases
- particles
- airborne pathogens
What law was passed in the USA to control air pollution? What does it focus on controlling?
1970 Clean Air Act - clean air should be maintained in houses, workplaces, hospitals, surgery rooms, industries, and slaughterhouses
air-borne contaminants in the atmosphere, or else microbes from the air will drop into wounds, surgical sites, food, and meat, or be inhaled and cause disease
Why is exposure to air pollutants so significant?
it is continuous and involuntary - cannot be avoided
What 6 types particulate matter pollute the air?
- AEROSOLS - any tiny solid or liquid particles
- DUSTS - solid particles from grinding or crushing
- FUMES - solid particles occurring when vapors condense
- MIST/FOG - liquid particles
- SMOKE, SOOT, ASH - solid particles (carbon) from combustion
- SMOG - any air pollutant
What are the 6 major air pollutants that are known to cause smog, acid rain, and health hazards?
- O3
- CO
- SO2
- NO2
- particulate matter
- lead
What are the 4 broad types of air pollutants that cause air-borne disease?
- biological - COVID-19, SARS, flu, TB, Chlamydia, Q fever, anthrax, fungi
- allergens - cats, mites
- physical - particulate matter, volcanic ash, radioactivity, cement dust, smoke from fires
- chemical - gases, ammonia, CO, CO2, SO2, NO2, methane, chlorofluorocarbons
What type of air pollutants make up most of the total mass emitted into the atmosphere?
chemical gases = 90%
What are the 3 types of particulate matter based on size?
- inhalable coarse particles with a diameter of 2.5-10 µm (PM10)
- fine particles with a diameter of 0.1-2.5 µm (PM2.5)
- ultrafine particles with a diameter of 0.1 µm or less (soot)
they are all able to be suspended in the air and inhaled
What is the typical size and make-up of particulate matter? What is their porosity like?
0.01-100 µm —> solid or aqueous
such that they can absorb/adsorb other gases, liquids, and solids
What kind of particulate matter is the most dangerous? What 4 things do they most commonly cause?
those below 2.5 µm, since they can penetrate all sites of the respiratory tract
- heart attacks
- respiratory disease
- premature death
- cancer (group 1 carcinogens)
Air-borne hazards that cause allergies, cancer, respiratory/lung disease, and cardiovascular disease:
Air-borne pathogens:
What is characteristic of air-borne pathogen transmission?
can jump from animals to humans and jump back from humans to animals
What pathogens are more significant in the air? Why? How are they transmitted?
viruses, bacteria, fungi —> parasites and protozoa are too large to stay suspended in the air and be inhaled
launching pathogens and spores of pathogens from the ground into atmospheric air, like a parachute (sneezing/breathing)
What are the 3 steps required for airborne transmission?
- launched into air from a donor, like humans, animals, vegetation, water, soil, and industries
- transported by wind, precipitation, dust, machinery (airplanes), migratory birds, flying insects, and people
- deposited or landed in a new location on a new recipient, like humans, animals, vegetation, soil, and water
How can humans stop the transmission of air-borne pathogens?
cover while sneezing or coughing
Viruses, bacteria, and fungal spores able to be launched in the air:
What bacteria is known to be launched in liquid particles into the air from water stores?
Legionella is launched in mist (tiny water droplets)
What causes Q fever? How is it transmitted? How far can it be transmitted?
Coxiella burnetii
dispersed from animals’ breath from livestock holdings in the wind
20 km
Anthrax is mostly transmitted through contact. Where can it be commonly transmitted in the air?
launched from contaminated livestock hides and skin in the leather industry after processing (5%)
What are the 3 transmission routes of respiratory zoonotic diseases?
- person-to-person from direct touches of exhanging of body fluids = contagious disease
- droplet spread that travels a few feet (close) from coughing, speaking, and sneezing
- air-borne transmission that travels long distances
How is measles transmitted?
air-borne —> can travel long distances
- can catch it by entering a room after someone with measles has departed
How does air-borne transmission compare to soil-borne and water-borne transmission?
there are significantly less atmospheric microorganisms, but once they are suspended in the air, they can travel long distances with the help of wind, dust, particulate matter, and precipitation to land on a new recipient
Why are air-borne pathogens more likely to become pandemic?
we cannot stop breathing in and out air —> involunutary —> easy spread
What 3 things do the symptoms of respiratory disease depend on?
- type of pathogen
- location of respiratory tract affected
- severity of damage on the affected respiratory tract
What are the 3 major air-borne zoonoses that caused pandemics in history?
- Yersinia pestis from rodents - Black Plague
- Influenza virus - 5 flu pandemics
- Coronavirus - 3 pandemics
What are the 4 major emerging zoonotic pathogens of respiratory disease?
- SARS
- MERS
- pandemic influenza
- Legionella
What is the aim to monitoring and surveilling air quality? What 3 hazards are measured when doing this?
prevent and control air-borne diseases if the concentration of hazards in the air is above the maximum acceptable level
- pathogens - ~50 CFU/m^3
- hazardous gases
- particulate matter - coarse (PM10), fine (PM2.5) = 12 µg/m^3
Air quality standards for microbial maximum limit:
The USA has standards for what 5 classes of air pollutant hazardous gases? What is the maximum limit for particulate matter?
- sulfur dioxide (SO2)
- carbon monoxide (CO)
- ozone (O3)
- nitrogen dioxide (NO2)
- lead (Pb)
COARSE (PM10) = 150 µm/m^3
FINE (PM2.5) = 12-15 µm/m^3 —> 35 µm/m^3
What are the 9 ways air-borne diseases can be controlled?
- treating infected/ill people and animals to minimize launching pathogens into the air
- vaccination to minimize pathogen reproduction and amplification (COVID-19, Influenza)
- cleaning, sanitizing, and disinfecting environment to reduce germ buildup
- hand washing thoroughly for at least 20 seconds
- PPE: masks, cover up coughs and sneezes to reduce launching
- social distancing: avoid close contact with infected animals and people without PPE
- using a respirator with HEPA filter
- quarantine
- reduce hazardous gas production and release into atmosphere by industries
