ENVIRONMENTAL, OCCUPATIONAL & WORK-RELATED DISEASES Flashcards
Environmental diseases?
Conditions caused by exposure to chemical or physical agents in the ambient work place and personal environment.
What is Pneumoconiosis?
Pneumoconiosis is the general term for a class of interstitial lung disease where inhalation of dust (for example, ash dust, lead particles, pollen grains etc) has caused interstitial fibrosis.
List down the factors that determine the pathogenicity of Pneumoconiosis.
- Amount of dust retained.
- Size, shape and buoyancy of particles.
- Particle solubility and physio-chemical reactivity .
- Additional effect of other irritants.
Aetiology of Black lung disease?
- Aka Coal Worker’s Pneumoconiosis.
- Caused by inhalation of coal particles or other admixed forms of dust .
Other conditions that coal workers are susceptible to? ( Apart from Pneumoconiosis)
- Progressive disease if coal dust is contaminated with silica.
- Emphysema.
- Chronic bronchitis.
Outline the major clinical features of Coal Worker’s Pneumoconiosis.
- Usually benign at first, causing little decrease in lung function .
- Increased pulmonary dysfunction.
- Pulmonary hypertension.
- Cor pulmonale in <10% of cases.
- Increased risk of lung cancer.
What are the other health conditions associated with Coal Worker’s Pneumoconiosis infections?
- Cancer
- Pharyngitis
- Pneumonia
- Bronchitis
- Anthracosis
- Fibrosis
- Pleurisy
- Legionnelosis
- Asthma
Steps in pathogenesis of Pneumoconiosis?
- Carbon pigment is inhaled .
- It is engulfed by alveolar/ interstitial macrophages , and accumulates in lymphatics.
What are the major distinguishing features of Simple Coal Worker’s Pneumoconiosis?
- Coal macules ( 1-2 mm in diameter).
- Nodules scattered throughout the lung.
- Mainly affects upper lobes / upper zones of lower lobes.
- Infection appears adjacent to respiratory bronchioles .
- May give rise to centrilobular emphysema .
What are the major distinguishing features of Complicated/ progressive Coal Worker’s Pneumoconiosis?
- Occurs on the background of simple disease and requires many years to develop.
- Multiple intensely blackened scars >1 cm .
- Lesions consist of dense collagen fibers and pigments.
- Necrotic center due to local ischaemia.
What is Silicosis?
- Silicosis is a form of occupational lung disease caused by inhalation of pro-inflammatory crystalline silica dust( silicone dioxide).
- It is marked by inflammation and scarring in the form of nodular lesions in the upper lobes of the lungs.
3 major presentations of Silicosis?
- Slowly progressing
- Nodular
- Fibrosing Pneumoconiosis
Markers of acute silicosis?
- Heavy exposure to silica over a period of months to years .
- Accumulation of abundant lipoproteinaceous material within the alveoli.
What are some of the occupations where workers are pre-disposed to silicosis?
- Repair/ demolition of buildings and roads .
- Stone carvers.
- Jewelers using chalk molds.
- Sandblasting.
- Mining .
- Construction work including: drilling, demolition, cutting, grinding and road work.
Chest X-ray of a patient with silicosis will reveal?
Fine nodularity in upper zones of the lungs .
What clinical manifestations are seen in the early stages of Silicosis?
Tiny , barely palpable, discrete black nodules seen in hilar lymph nodes and upper zones of the lungs.
What clinical manifestations are seen in progressive stages of Silicosis?
- Nodules may undergo central softening/ cavitation.
- Fibrotic lesion in hilar lymph nodes and pleura.
- Egg shell calcification.
- Expansion and coalescence of lesions.
- Progressive massive fibrosis.
- Increased susceptibility to Tuberculosis infections.
Histological signs of Silicosis infections?
- Central area of whorled collagen fibers .
- Peripheral zone of dust - laden macrophages.
Most commonly used type of asbestos?
Serpentine chrysotile - aka white asbestos.
List down the major conditions associated with exposure to asbestos.
- Pulmonary fibrosis.
- Carcinoma.
- Mesothelioma.
- Pleural effusions.
- Laryngeal & ovarian carcinoma.
Clinical conditions associated with Serpentine chrysotile exposure?
- Asbestosis
- Mesothelioma
- Lung cancer
List down some of the activities that may lead to asbestos exposure.
- Mining and manufacture of asbestos.
- Shipbuilding and aircraft manufacturing.
- Dock & rail workers - unloading asbestos from ships/ trains.
- Thermal and fire insulation - lagging.
- Construction, building repair and demolition.
- Plumbers and gas fitters.
- Car mechanics ( brake linings).
- Electricians, carpenters , upholsterers.
- Manufacture of gas masks in World War II.
- Family members of the above, and/or working or living near an asbestos source ( particularly if asbestos fibers are taken home on worker’s clothing).
