Occupational Lung Diseases (L20) Flashcards
Name the 2 types of dust diseases.
List the molecules that cause each of them.
Mineral:
- Coal
- Silica
- Asbestos
- Beryllium
Organic:
- Cotton
- Flax
- Prawn
- Hay
- Bird Droppings
Particles > ___ um are unlikely to reach the distal airways.
10.
Particles < ___ um act as gases moving in and out of the alveoli.
0.5.
What size particles (in um) are the most dangerous as they may accumulate in the lung?
1-5.
Name the disease.
- Deposition and retention of inorganic dust in the lungs and the subsequent tissue reactions.
- Particles are 1-5 um in diameter.
• In the majority of cases it is caused by non-fibrous
mineral dusts e.g. Coal, Silica, beryllium.
• The most common form is caused by coal dust.
Pneumoconiosis.
Name the important alveolar macrophage mediators.
(3 classes)
Give examples.
a) Toxic Factors – Reactive oxygen species
b) Pro-inflammatory Mediators – Oxidative stress activates NF-kB leading to the production of IL-1, TNF-a, IL8 etc
c) Fibrogenic Factors – IL-1, TNF-a, PDGF and others increase fibroblast proliferation and activation
Describe chronic fibrosis.
- Progressive massive fibrosis with large nodules > 10 um present
- This leads to severe respiratory impairment. The end stage of which is ‘honeycomb lung’.
List the effects of ‘Honeycomb Lung’.
5
- Decreased Lung Capacity
- Increased Residual Volume
- Decreased Compliance
- Decrease in Pulmonary Capillaries
- Pulmonary Hypertension
Read:
Stages in Coal Workers Pneumoconiosis.
- Pulmonary Anthracosis
• Most innocuous
• Also commonly seen in all urban dwellers and smokers
• Inhaled carbon engulfed by alveolar
• Accumulate in connective tissue along the lymphatics. - Simple CWP
• Characterised by coal macules and somewhat larger coal nodules scattered throughout the lung.
• Dilation of adjacent alveoli sometimes occurs (Centrilobar Emphysema)
• Little or no pulmonary dysfunction. - Complicated CWP or Progressive Massive Fibrosis.
• Approx 10% of cases CWP lead to PMF
• Takes many years to develop
• Characterised by multiple balackened scars (2 cm - 10 cm diameter)
• Consist of dense collagen and pigment
• Centre of the lesion is necrotic
• Lung function is severely affected
Name the disease.
- Due to inhalation of crystalline silicon dioxide (Silica) dust
- Most common in third world countries
- Disease presents after decades of exposure (20 - 30 years)
- Particles of approx 1 um are particularly apt to be retained to cause fibrosis
- Sources are - mining, quarrying, sand blasting, tunnelling, foundry, pottery
Silicosis.
Name the Asbestos Related Lung Cancer.
- A malignant tumour of the pleura (at least 90% of cases associated with asbestos exposure). Develops in the mesothelium, the protective lining that covers the lung.
- The risk is greatest in those exposed to blue asbestosis with the period of exposure sometimes being as short as a few months.
- At present there are about 2000 deaths a year in the UK.
- As the tumour progresses it may encase the lung and metastasis. Prognosis is poor with most patients dying within 2 years of diagnosis
Mesothelioma.
Name the Asbestos Related Lung Cancer.
The disease is classified into two groups
1) Small cell carcinoma – 20%
2) Non small cell carcinoma 80% - Squamous cell (45%), adenocarcinoma (20%) and large cell carcinoma (15%)
- Small cell carcinoma is highly malignant and has usually widely disseminated by the time of diagnosis
- Combination chemotherapy achieves symptom relieving remission in 80% of patients and prolongation of survival from 3 months to 11 months
- Surgical removal of the tumour is the best chance of cure in non small cell carcinoma
Bronchial Carcinoma.
Which hypersensitivity type and lung disease type is allergic Asthma.
1.
Obstructive Lung disease.
Which hypersensitivity type and lung disease type is Extrinsic Allergic Alveolitis (Hypersensitivity Pneumonitis).
3.
Restrictive Lung Disease.
Describe Extrinsic Allergic Alveolitis (EAA).
- Hypersensitivity reactions occur in terminal bronchioles and alveoli after inhalation of a variety of antigens
- Occurs only in susceptible individuals
- Occurs after repeated inhalation
- Leads to acute or chronic interstitial inflammation of the lungs
