Airborne Diseases Flashcards
What is environmental air composed of?
Air composed of nitrogen (78%), oxygen (21%), argon (0.9%), & other gases including air pollutants (0.1%)
Most respiratory diseases are due to?
Most Respiratory diseases are due
to inhaling harmful air pollutants
from the air, which include:
1. Harmful gases,
2. Particles
3. Airborne pathogens
What standards did the Clean Air Act of 1970 establish?
Clean air should be maintained in
your house,
working places,
hospitals,
surgery rooms,
industries,
slaughterhouses, etc
It focuses on controlling airborne contaminants in the atmosphere (pathogens, particles, harmful gases, etc.)
Or else, microbes from air drop on to wounds, surgical operation, food, meat, etc. or inhaled
What is the significance of air?
A person inhales approximately 30 m3 of air per day
* Roughly 6 times more than the food and drink consumed per day
* Exposure to air pollutants is continuous and, usually, involuntary
1. Air Pollution - Our World in Data = kills over 7 million people (9% of all 56 million deaths) each year
What are the 6 common air physico-chemical pollutants known in the USA?
Six common air physico-chemical pollutants known in
USA include six Particulate Matter (PM) & harmful gases
1. Aerosols
Any tiny solid or liquid particle
2. Dusts
Solid particles from grinding or crushing
3. Fumes
Solid particles occurring when vapors condense
4. Mist, fog
Liquid particles
5. Smoke, soot, ash
Solid particles, mostly carbon, from combustion
6. Smog
Any air pollutant; originally meant smoke plus fog
What are the six major air pollutants that are known causing smog, acid rain, & health hazards?
- O3,
- CO,
- SO2,
- NO2,
- particulate matter,
- lead
What are the four types of air pollutants that cause airborne diseases?
dusts and smoke contain toxic gasess or particles. These gases and particles we can classify into four categories.
Three types of atmospheric (airborne) particles based on size include:
1. inhalable coarse particles, designated PM10
particles with a diameter of 2.5 - 10 μm
2. fine particles, designated PM2.5
particles with a diameter of 0.1 - 2.5 μm
3. ultrafine particles,
particles with diameter of 0.1 μm or less; and soot
Three of them are:
suspended particulate matter (PM)
thoracic and inhalable particles
PM are solid or aqueous of size 0.01 to 100μm
* In addition, PM have the following features:
Carbonaceous dust, metallic oxides, salts, or acids
Porosity such that they absorb/adsorb other gases, liquids, and solids
1. PM below ~ 2.5μm the most dangerous (inhaled –> alveoli –> BV –> heart –> brain –> repro organs; repsi disease, premature death, cancer.
Because they can penetrate all sites of the respiratory tract.
Particulates are the most harmful form of air pollution due to their ability to
penetrate deep into the lungs, blood streams, heart, & brain causing:
1. heart attacks,
2. respiratory disease,
3. premature death, and
4. Cancer (PMs are designated as Group 1 carcinogen)
What are the sources of zoonotic airborne pathogens?
- Humans
- Animals
a. Domestic animals
b. Aquatic animals
c. Wild animals - Others also launch
a. vegetation,
b. water
c. soil
d. industries
Describe how airborne pathogens can jump from animals to humans and vice versa.
Only virus, bacteria, and fungus are more common because bigger parasites cannot be
suspended in the air
How are airborne pathogens launched from the ground and into the atmosphere?
Legionella is transmitted by
mist (tiny water droplets) from
contaminated water bodies
protozoa and worms are not airborne
Launching airborne viral, bacterial, or fungal zoonotic diseases into the air by
humans & animals
Explain how Coxiella burnetii is transmitted from the air into livestock holdings.
How do anthrax spores contaminate livestock hides and skin in the leather industry?
How are respiratory diseases transmitted from person to person?
Person-to-person contact = contagious disease
Infectious diseases are commonly transmitted through direct person-to-person contact.
Transmission occurs when an infected person touches or exchanges body fluids with others.
This can happen before an infected person is aware of the illness.
How are respiratory diseases transmitted via droplets?
Droplet spread (travel a few feet)
The spray of droplets during coughing and sneezing can spread an infectious disease.
You can even infect another person through droplets created when you speak.
Since droplets fall to the ground within a few feet, this type of transmission requires close-proximity.
How are respiratory diseases transmitted via distance?
Airborne transmission (travel long distance)
Some infectious agents can travel long distances and remain suspended in the air for an extended period.
You can catch a disease like measles by entering a room after someone with measles has departed.
There are significantly less atmospheric microorganisms than there are in
water/oceans and in soil
However, once airborne pathogens suspended in the air column from the donor,
these microbes can travel long distances with the help of
wind, dust, PMs, and precipitation to land on a recipient
Above all, we cannot stop breathing in and out air because our respiratory
system works under involuntary control; hence,
airborne pathogens are dangerous and easily spread
Therefore, airborne pathogens can cause a widespread disease …. sometimes become pandemic
What are the symptoms of a respiratory disease?
What is the history of airborne zoonoses that have causes pandemics?
corona = 3 x
sars -> bats, etc
pigs like influenza (swine)
mers –> middle east
sars in far east
List the four major emerging zoonotic pathogens of respiratory diseases
What is the purpose of monitoring and surveying air quality?
Its aim is to prevent and control airborne diseases if the concentration of hazards in air is
above the maximum acceptable level
Done by measuring for the concentration of the following hazards in a volume (m3) of air:
1. pathogens (CFU/m3) = ~50 CFU/m3
2. hazardous gases =
3. PM i. e. course (PM10) and fine (PM2.5) particulate matter = 12 μg/m3
What are the air quality standards for microbial maximum limit in the air?
What are the USA’s standards for limiting the six classes of air pollutants?
How do you control airborne diseases?
- Treating infected/ill people and animals to minimize launching of pathogens to the air
- Vaccination of animals and people against airborne zoonotic pathogens to minimize pathogen
reproduction & amplification e. g. Covid-19, Influenza, etc. - Cleaning, sanitizing, and disinfection of the environment to reduce germ build up
- Hand washing thoroughly (at least 20 seconds) and often
- PPE: Masks, cover your cough to prevent pathogen launching to the atmosphere
- social distancing = Avoid close contact with infected animals and people without PPE
- Respirator including high efficiency particulate air (HEPA) filter to filter:
air particulates, viruses, bacteria & fungi in hospitals, laboratories, etc. - Quarantine
- Reduce hazardous gas production and release to the atmosphere by industries
