Pulmonary Occupational Diseases Flashcards
Describe the absorption of air?
absorption from the lungs is greater than from the mouth or gut, which is greater than through the skin
Describe the absorption of particles in the lungs?
Particles can only reach the bottom of the lungs (alveoli) if they are small enough (less than 10 microns) aerodynamic diameter
- 1 micron: likely to be deposited in alveoli
> Particles absorbed, cause reaction, lung cancer
> Time from exposure to disease may be long (decades)
What are pulmonary occupational diseases?
Acute or chronic disorder arising from inhalation of airborne agents in the workplace
- Over 80% of chemicals gain access to body via pulmonary system
Name ways to conduct pulmonary testing?
- X-rays
- may not always show disease - spirometry
- screening test
What is the function of spirometry?
measure airway resistance to air flow
Note: Disease may develop before pick up by spirogram
- Small airways (less than 2mm) contribute less to spirogram but affected earlier that larger airways
When is spirometry conducted in occupational health?
- pre and post employment
- disability evaluation
What is vital capacity?
Max volume of air that patient exhales after maximal inhalation
- FVC1: exhaled in 1 second
- Reduction in VC, FVC1 implies airway Obstruction
What is residual volume and TLC and their disease interpretation?
Increase in RV and RV/TLC ratio implies air distention and air trapping disease (Emphysema)
What are simple asphyxiants?
Interfere with air exchange by displacing oxygen from the air breathed in
e.g. Methane, Nitrogen, Carbon dioxide
Where are simple asphyxiants mostly found?
Enclosed, poorly ventilated spaces
- underground where methane can be produced by naturally occurring processes
What are symptoms of simple asphyxiation?
- breathlessness due to lack of oxygen.
- rapid breathing, headache and sweating
- loss of consciousness and death can result
How to prevent simple asphyxiation?
- Make sure tank is aerated
- Work in pairs:
- Person in the tank is attached to a rope
- Person on top should be ready to pull if colleague is overcome by chemical
What are chemical asphyxiants?
Interferes with transport of oxygen by hemoglobin from lungs to tissue
1. Higher affinity for Hb than O2
e.g. carbon monoxide
2. Cytochrome A oxydase inhibited
e.g. hydrogen cyanide
3. hydrogen sulfide
e.g. interferes with oxidative enzymes
Describe the characteristics of carbon monoxide?
colourless and odourless
Where is carbon monoxide usually found?
- Iron steel foundries
- welding
- garage
- paper mills
- gasoline forklifts
What are the symptoms of carbon monoxide asphyxiation?
headache, dizziness, loss of consciousness
Treatment of carbon monoxide asphyxiation?
- O2 intubation,
- hyperbaric chamber O2
How do you get hydrogen cyanide asphyxiation?
- Acid contact with cyanide compounds
- Burning of acrylonitrile plastics
