ENVIRONMENTAL, OCCUPATIONAL & WORK-RELATED DISEASES

Question 1

Environmental diseases?

Answer 1

Conditions caused by exposure to chemical or physical agents in the ambient work place and personal environment.

Question 2

What is Pneumoconiosis?

Answer 2

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.

Question 3

List down the factors that determine the pathogenicity of Pneumoconiosis.

Answer 3

• Amount of dust retained.
• Size, shape and buoyancy of particles.
• Particle solubility and physio-chemical reactivity .
• Additional effect of other irritants.

Question 4

Aetiology of Black lung disease?

Answer 4

• Aka Coal Worker’s Pneumoconiosis.
• Caused by inhalation of coal particles or other admixed forms of dust .

Question 5

Other conditions that coal workers are susceptible to? ( Apart from Pneumoconiosis)

Answer 5

• Progressive disease if coal dust is contaminated with silica.
• Emphysema.
• Chronic bronchitis.

Question 6

Outline the major clinical features of Coal Worker’s Pneumoconiosis.

Answer 6

• 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.

Question 7

What are the other health conditions associated with Coal Worker’s Pneumoconiosis infections?

Answer 7

• Cancer
• Pharyngitis
• Pneumonia
• Bronchitis
• Anthracosis
• Fibrosis
• Pleurisy
• Legionnelosis
• Asthma

Question 8

Steps in pathogenesis of Pneumoconiosis?

Answer 8

• Carbon pigment is inhaled .
• It is engulfed by alveolar/ interstitial macrophages , and accumulates in lymphatics.

Question 9

What are the major distinguishing features of Simple Coal Worker’s Pneumoconiosis?

Answer 9

• 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 .

Question 10

What are the major distinguishing features of Complicated/ progressive Coal Worker’s Pneumoconiosis?

Answer 10

• 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.

Question 11

What is Silicosis?

Answer 11

• 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.

Question 12

3 major presentations of Silicosis?

Answer 12

• Slowly progressing
• Nodular
• Fibrosing Pneumoconiosis

Question 13

Markers of acute silicosis?

Answer 13

• Heavy exposure to silica over a period of months to years .
• Accumulation of abundant lipoproteinaceous material within the alveoli.

Question 14

What are some of the occupations where workers are pre-disposed to silicosis?

Answer 14

• Repair/ demolition of buildings and roads .
• Stone carvers.
• Jewelers using chalk molds.
• Sandblasting.
• Mining .
• Construction work including: drilling, demolition, cutting, grinding and road work.

Question 15

Chest X-ray of a patient with silicosis will reveal?

Answer 15

Fine nodularity in upper zones of the lungs .

Question 16

What clinical manifestations are seen in the early stages of Silicosis?

Answer 16

Tiny , barely palpable, discrete black nodules seen in hilar lymph nodes and upper zones of the lungs.

Question 17

What clinical manifestations are seen in progressive stages of Silicosis?

Answer 17

• 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.

Question 18

Histological signs of Silicosis infections?

Answer 18

• Central area of whorled collagen fibers .
• Peripheral zone of dust - laden macrophages.

Question 19

Most commonly used type of asbestos?

Answer 19

Serpentine chrysotile - aka white asbestos.

Question 20

List down the major conditions associated with exposure to asbestos.

Answer 20

• Pulmonary fibrosis.
• Carcinoma.
• Mesothelioma.
• Pleural effusions.
• Laryngeal & ovarian carcinoma.

Question 21

Clinical conditions associated with Serpentine chrysotile exposure?

Answer 21

• Asbestosis
• Mesothelioma
• Lung cancer

Question 22

List down some of the activities that may lead to asbestos exposure.

Answer 22

• 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).