Airborne Hazards- Anticipation and Recognition Flashcards
What separates the upper and lower respiratory system?
Larynx
What are the parts of the upper respiratory system?
mouth/ throat/ oral cavity
What are the parts of the lower respiratory system?
- tracheae and bronchi (Tracheobronchial or thoracic)
- Pulmonary - lower section with alveoli
Describe the alveoli
- thin lining for oxygen exchange
- acinus
- important to protect from contaminants
What happens to air velocity as it goes through the lungs?
changes
Describe the physiology and defense mechanisms of the nose.
- Turbinates add moisture and warm up the nose
- traps large particles
- hair
- nostrils face down so things cannot fall into nostrils
- 90 degree bend at back of nose with mucus
Was size particle can enter the nose?
inhalables
does mouth offer the same protection as the nose?
no
Describe the trachea physiology
- mucous
- cartilage rings that keep expanded
- takes air into the lungs
What is a common location for cancer in the respiratory tract?
location where trachea branches into bronchi due to toxicant impaction
Describe the bronchi and it’s fcuntion
branch into bronchioles than alveoli. takes air to alveoli
Describe the defense mechanisms and speed of clearance in the upper respiratory system
- hair
- mucous
- mucociliary escalator (moves particles up and out so we cough or swallow them)
- fast clearance
Describe the defense mechanism and speed of clearance in the lower respiratry syste.
Slow clearance
Macrophages- WBC that engulf and digest foreign material
Digested particles taken to the lymphatic system
What are the potential systems the upper/ lower respiratory system an have based on their clearance?
URT- Systemic to GI tract
LRT - systemic to lymphatic system
Why is the breathing rate important?
breathing rate influences the risk
What is vital capacity?
VC- volume expired in a maximum expiration after maximum inspiration
What is the term for the maximum air expired in the first second of VC?
Forced Expiatory Volume (FEV1)
What is science of the measurement of air?
spirometry
What is the importance of spirometry?
it tests for restrictive and obstructive conditions
What is an aerosol?
Collection of solid or liquid particles suspended in gas
Why are small aerosols a concern?
they stay suspended in the air longer
what is the maximum size for an inhalable aerosol?
100 um or less
What are the types of aerosols?
- dusts
- mist-
- smoke
- fumes
What occupation creates a lot of fumes?
welding - from melting the metal
How can aerosols find people?
- small particles through ventilation systems and turbulence / convection
- larger particles clump or settle and can be resuspended with activity like walking on carpet
What primarily determines the particulate matters deposition in the body?
Size
can statistically predict where a particle will deposit in the RT based on the aerodynamic diameter
What can happen to a deposited particle?
It will be cleared or retained
Are all aerosols deposited?
No, some are breathed in and exit on the exhale
What is the equation for retention?
Retention = deposition - clearance
What determines the amount of damage caused by the aerosol?
1) Rate of clearance
2) Deposition location
3) CHemical and biological properties of agent
4) host factors
Give an example of chemical/ biological properties that can cause different levels of damage in the body
iron - little or no damage
lead - very high amounts of damage
Describe unit density spheres
- not all the same shape
- ex - particles that clump together
- measure by behavior versus shape (where they end up in lungs)
aerodynamic diameter
the diameter of a unit density sphere that settles at the same velocity as the particle in question
If two particles have the same aerodynamic diameter, do they have the same shape?
NO
Describe what happens to the time suspended in the air as the size of the particle increases. Example.
As the size of the particle increases, the time in the air decreases.
Example- .5 um stays suspended for 41 hours while 100 um stays suspended for 5.8 seconds
What may impact the size distribution and concentration of particles?
different work processes
How does energy and heat impact the size of particles in the workplace/
hotter processes that require more concentrated energy, like welding, break atoms and create smaller particles. However, more mechanical processes do not have the same amount of energy and create larger particles.
We looked at two machines in class that measure particle diameters and distribution. How do they work.
Gray machine - measures smaller particles (up to 500 nm or .5 um) created from concentrated energy. envelopes the particles in alcohol and measures with laser.
Grimm machine- measures larger particles (>500 um). two lasers and measures the time it takes to travel from one to the other
Name 3 static properties that can influence our ability to sample and control them
- size
- solubility
- electric charge
What are the dynamic properties of aerosols? (how do they move)
1) impaction
2) Interception
3) Diffusion
4) Filtration - through engineering or PPE controls
How do the largest particles deposit?
Sedimentation (drop)
Describe how particles can deposit
impaction
interception
diffusion
Describe impactiion and where it primarily occurs
Upper respiratory tract- when the air move direction, the particle wants to go straight and deposits where it hits (ie where trachea branches into bronchi).
Usually larger inhalable particles
Describe Interception
particle small enough to follow the direction of the air, but gets stuck and deposits
Describe diffusion
occurs in the lower respiratory system
-particles even smaller than air, they get bounced around in a random pattern and hit something
What is another name for the movement of diffusion
Browmian movement
What decreases the dose in the respiratory tract?
defense mechanisms and clearance
What is the size of inhalable particles and where can they reach?
<100 um, can enter the nose
What is the size of thoracic particles and where can they reach?
<40 um, into the trachea and bronchi
What is the size of respirable particles and where can they reach?
<10 um, pulmonary region
What size particles are the most concerning?
respirable particles
How does size relate to deposition?
as size goes up, probability of depositing goes down
What is the ideal size to breathe out and never deposit?
0.3 um or 300 nm
What size particle typically impacts in the upper respiratory system?
larger inhalable particles
What size particle is the worst in terms of depositing in the pulmonary region?
10um- respirable
Note- nose and thoracic region trap the larger particles
Are diseases of the pulmonary region reversible?
no
Name diseases caused by aerosols in the upper respiratory system
- irritation
- infection
- allergic reaction
- cancer
How can irritation impact the upper respiratory system
- inflammation
- necrosis
- ulceration
What type of cancers can be caused in the upper respiratory system
- Nasal
- Laryngeal
What diseases can result from aerosols depositing in the tracheobronchial region
- irritation
- infection
- allergic reaction
- cancer
What is cancer of the tracheobronchial region called?
bronchiocarcinoma
What diseases can result for aerosols depositing in the pulmonary region?
- irritation
- infection
- fibrosis
- emphysema
describe fibrsis, example
scarring tissue formed
ex- silca - silicosis
Describe emphysema
- alveoli coalesce and there is less surface for gas exchange
What three conditions lead to inflammation?
Irritation
Infection
Allergic Reactions
Name the types of bioaerosols
1) Fungi
2) Bacteria
3) viruses
4) dust mite droppings
5) pollen
6) endotoxins
How much extra bacteria does high pressure food equipment cleaning eject into the air?
3-10 x
What is the bioaerosol concern with metal working?
metalworking mists contain microorganisms and endotoxins that can cause hypersensitivity and asthma
What determines how bad the bioaersol is?
- viability
- virulence
- communicability and transmission
- host factors (age, other disease, smoker, etc.)
What is a biofilm?
Thin layer of microorganisms that coat a surface (Aggregations)
How many of all human infections are due to biofilms?
65%
How can biofilms be aerosolized
high pressure air or water hoses
Examples of biofilms
Legionella, TB
What is a gas?
Chemicals that have no shape but expand to fill the container that they are in
What is a true gas?
Gaseous at room temperature
What is a vapor?
When a liquid or solid sublimates to form a vapor about the solution or the solid
How do gasses move?
Diffuse from higher concentrations to lower concentrations
What is volatility?
The tendency of a substance to vaporize (directly related to the vapor pressure)
What is VHR?
The vapor hazard ratio- measurement for solvent volatility
What is the equation for VHR?
Vapor Pressure (from NIOSH) at 25 degrees C / TLV
What are the characteristics of gasses?
concentration
reactivity
solubility (air vs. liquid)
What characteristic of gas is most important when determining it’s health effects?
Solubility
What is the most common health effect of gasses?
Irritation- 80% of all gaseous chemicals are irritants
Describe inflammation
- caused by irritation
- redness
- swelling
- heat
- pain
- decrease in function
What are the effects of irritation from gasses in the upper respiratory tract?
- increase in mucus
- decreased ciliary beating
- bronchoconstriction
What are examples of gaseous sensory irritants?
ammonia and HCL
What impact can gaseous irritants have on the lower respiratory system?
- damage to lining
- pulmonary edema
- kill macrophages
- damage to surfactants
What are examples of gaseous pulmonary irritants?
NOx, Phosgene, Chlorine
What is the name of gasses that impact the lower respiratory system?
respiratory irritants
What is the difference between simple and chemical asphyxiants?
Simple asphyxiants- displace oxygen, problem if oxygen drops below 20%
Chemical- body cannot transport O2, or cells cannot use O2
What are examples of chemical asphyxiants?
CO, Cyanide
What are the health effects of gasses?
- irritation *
- Asphyxiation
- Necrosis/ Amnesia
What chemical often causes necrosis/ anethesia?
Many solvents
How do gases cause nacrosis/ anethesia? What are the symptoms?
inhaled and distributed to depress the CNS
Symptoms: dizzy, light headed, sleepy, nausea
What is the difference between simple and complex gasses?
simple: only impact the CNS
Complex: impact the CNS and other organs
Define confined spaces
Limited, restricted entry/ exit, not intended for employee to complete work inside
What are the concerns with confined spaces?
- oxygen deficiency
- toxic and/ or flammable gasses
What are the two most dangerous chemicals in confined spaces?
Carbon monoxide and hydrogen sulfide
What explosive gas can be found in confined spaces?
Methane
What needs to be done if chemicals are detected in a confined space?
Ventilate fresh air INTO the space
What is needed for a fire?
Fuel
Oxygen
Ignition
Propagation (maintains the chemical reaction)
Define flash point
Minimum temperature to ignite a flame (can flash and die)
Define Fire Point
Minimum temperature to maintain a flame
Define Flammable Liquid and example
any liquid having a flash point below 100 degrees F (always at flash point, event at room temp). Gas is example)
Define Combustible Liquid and example
liquids that have a flash point at or above 100 degrees F (Needs to be heated to ignite). Ex- diesel
Define Flammable or Explosive Range
difference between the lower and upper flammable limits, expressed in terms of percentage of vapor or gas in air by volume
What is the LEL?
Review
What is the UEL?
Review
What causes a reaction?
When the volume of products are greater than the reactants
Volume products > reactants
What can ignite an explosion?
static
What gasses can cause frostbite?
Cryogenic gasses
What is the concern with compressed gases?
Explosions
Oxygen deficiency
What are the concerns with outdoor Air quality?
- hazardous air pollutants (HAPS)
- Ozone depletion
- Global Warming
- Smog
- Non attainment
…the higher the vapor pressure at normal temperature…
the more volatile
Give an example of a volatile substance
Gasoline (vaporizes even at freezing temps)
What are examples of confined spaces?
Cisterns/ manholes
What can cause an explosion?
Flammable gasses, reactive chemicals in any form (even dust and steam)
Why are confined spaces more dangerous for explosions?
added pressure
Describe Indoor Air Quality
Air quality problems in buildings one would not expect to have problems in (ie offices, schools, libraries)
Describe SBS
sick building syndrome- ACUTE, symptoms stop when you leave the building
What are common symptoms of SBS?
Headache
Upper respiratory irritation
Nausea
What are the common SBS Agents?
1) CO
2) VOCs
3) ETS
4) CO2
5) Microbial Agents
6) Relative Humidity
What SBS agent should always be checked first?
CO
What does CO cause?
Fatigue, headache…death
What symptoms do VOCs cause?
headache, irritation
What are common VOCs?
formaldehyde, VOCs from furnishing
What does ETS contain?
Carbon Monoxide and VOCs
What do microbial agents cause when indoors?
irritation, headaches
What is an indicator of inadequate ventilation in buildings?
CO2
What is are the symptoms of a high CO2 concentration in a building?
Fatigue, sleepiness
What are the concerns with relative humidity?
Too low–> irritation
Too high–> microbial growth
What causes indoor air quality problems? give the % breakdown,.
- inadequate ventilation (50-60%)
- Indoor source (20%)
- outdoor source (10%)
- Unknown source (10%)
What allergens are considered to be indoor air quality agents?
- dust mites
- pet dander
- some chemicals
What microorganisms are indoor air quality agents?
- bacteria
- Legionella pneumophila
- mold
What indoor air quality agents can cause chronic disease?
1) Radon
2) Asbestos
3) ETS
Where is radon ususally found?
Basements of buildings with uranium rich soi
What are the second and third leading causes of lung cancer in the US?
#2- radon #3- ETS
What diseases does asbestos cause?
asbestosis, mesothelioma
How is CO produced?
Incomplete combustion, usually near a furnace
What can cause ETS in a building?
Ventilation intake near where people smoke
What is the ideal realative humidity?
less than 60 but more than 30
What is the acute health concern with ETS?
Constant inflammation which can depress the immune system
