Airborne Diseases

Question 1

What is environmental air composed of?

Answer 1

Air composed of nitrogen (78%), oxygen (21%), argon (0.9%), & other gases including air pollutants (0.1%)

Question 2

Most respiratory diseases are due to?

Answer 2

Most Respiratory diseases are due
to inhaling harmful air pollutants
from the air, which include:
1. Harmful gases,
2. Particles
3. Airborne pathogens

Question 3

What standards did the Clean Air Act of 1970 establish?

Answer 3

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

Question 4

What is the significance of air?

Answer 4

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

Question 5

What are the 6 common air physico-chemical pollutants known in the USA?

Answer 5

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

Question 6

What are the six major air pollutants that are known causing smog, acid rain, & health hazards?

Answer 6

1. O3,
2. CO,
3. SO2,
4. NO2,
5. particulate matter,
6. lead

Question 7

What are the four types of air pollutants that cause airborne diseases?

Answer 7

dusts and smoke contain toxic gasess or particles. These gases and particles we can classify into four categories.

Question 8

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

Question 9

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)

Question 10

Question 11

What are the sources of zoonotic airborne pathogens?

Answer 11

1. Humans
2. Animals
   a. Domestic animals
   b. Aquatic animals
   c. Wild animals
3. Others also launch
   a. vegetation,
   b. water
   c. soil
   d. industries

Question 12

Question 13

Describe how airborne pathogens can jump from animals to humans and vice versa.

Answer 13

Question 14

Only virus, bacteria, and fungus are more common because bigger parasites cannot be
suspended in the air

Question 15

How are airborne pathogens launched from the ground and into the atmosphere?

Answer 15

Question 16

Legionella is transmitted by
mist (tiny water droplets) from
contaminated water bodies

Question 17

protozoa and worms are not airborne

Question 18

Launching airborne viral, bacterial, or fungal zoonotic diseases into the air by
humans & animals

Answer 18

Question 19

Explain how Coxiella burnetii is transmitted from the air into livestock holdings.

Answer 19

Question 20

How do anthrax spores contaminate livestock hides and skin in the leather industry?

Answer 20

Question 21

How are respiratory diseases transmitted from person to person?

Answer 21

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.

Question 22

How are respiratory diseases transmitted via droplets?

Answer 22

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.

Question 23

How are respiratory diseases transmitted via distance?

Answer 23

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.

Question 24

 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

Question 25

What are the symptoms of a respiratory disease?

Answer 25

Question 26

What is the history of airborne zoonoses that have causes pandemics?

Answer 26

corona = 3 x
sars -> bats, etc
pigs like influenza (swine)
mers –> middle east
sars in far east

Question 27

List the four major emerging zoonotic pathogens of respiratory diseases

Answer 27

Question 28

What is the purpose of monitoring and surveying air quality?

Answer 28

 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

Question 29

What are the air quality standards for microbial maximum limit in the air?

Answer 29

Question 30

What are the USA’s standards for limiting the six classes of air pollutants?

Answer 30

Question 31

How do you control airborne diseases?

Answer 31

1. Treating infected/ill people and animals to minimize launching of pathogens to the air
2. Vaccination of animals and people against airborne zoonotic pathogens to minimize pathogen
   reproduction & amplification e. g. Covid-19, Influenza, etc.
3. Cleaning, sanitizing, and disinfection of the environment to reduce germ build up
4. Hand washing thoroughly (at least 20 seconds) and often
5. PPE: Masks, cover your cough to prevent pathogen launching to the atmosphere
6. social distancing = Avoid close contact with infected animals and people without PPE
7. Respirator including high efficiency particulate air (HEPA) filter to filter:
    air particulates, viruses, bacteria & fungi in hospitals, laboratories, etc.
8. Quarantine
9. Reduce hazardous gas production and release to the atmosphere by industries