Transcript pnumoconiosis

PNEUMOCONIOSIS
BY
DR KHALED ALTOHAMI
OBJECTIVES

1.
2.
3.
4.
5.
By the end of the lecture the students should be
able to:
Understand the concept of occupational
diseases.
Know the cause of occupational disease in brief.
Define pneumoconiosis.
Understand how dust can cause pulmonary
insult.
Identify the important dust diseases and have an
idea about the important ones of them.
OCCUPATIONAL DISEASES
Diseases arising out of or in the course of
employment.
 They may be grouped as under:

1.
2.
3.
4.
5.
6.
Diseases due to physical agents
Diseases due to chemical agents
Diseases due to biological agents
Occupational cancers
Occupational dermatosis
Diseases of psychological origin
(I) DISEASES DUE TO PHYSICAL AGENTS:
 e.g.
heat – cold – light – radiation –
noise – electricity – pressure
(II) DISEASES DUE TO CHEMICAL AGENTS:
1-Gases

CO2 – CO – NH3
2-Dust (pneumoconiosis):

a)
b)
c)
d)
(i)- Inorganic dusts:
Coal dust
Silica
Asbestos
Iron
Anthracosis
Silicosis
Asbestosis, cancer lung
Siderosis

a)
b)
c)
d)
(ii)- Organic (vegetable) dust:
Can fiber
Cotton dust
Tobacco
Hay or grain dust
Bagassosis
Byssinosis
Tobacossis
Farmers lung
3- Metals and their compounds:

Lead, mercury, cadmium
4- Chemicals:

Acids, alkalies, pesticides
5- Solvents:

Carbon bisulphide, benzene, chloroform
(III)- DISEASES DUE TO BIOLOGICAL AGENTS:

Brucellosis, anthrax, hydatosis, tetanus
(IV)- OCCUPATIONAL CANCERS:

Cancer of the skin, lungs, bladder
(V)-OCCUPATIONAL DERMATOSIS:

Dermatitis, eczema
(VI)- DISEASES OF PSYCHOLOGICAL ORIGIN:

Industrial neurosis, hypertension, peptic ulcer
PNEUMOCONIOSIS
Caused by dust within the size range of 0.5 to 3
micron and after a variable period of exposure.
 Dust is a chemical hazard.
 It is finely divided solid particles with size
ranging from 0.1 to 150 microns.
 They are released into the atmosphere during
crushing, grinding, abrading, loading etc.


They are produced in a number of industries
e.g. mines, foundry, quarry, pottery, textile,
wood or stone working industries.

Dust particles larger than 10 microns settle
down from the air rabidly, while the smaller
ones remain suspended indefinitely.

Particles smaller than 5 microns (respirable
dust) are directly inhaled into the lungs and
retained there and mainly responsible for
pneumoconiosis.
Dust
Inorganic
(silica, mica, coal,
asbestos, etc )
Organic
(cotton, jute)

Dust may be:
(a) soluble, which dissolve slowly, enter the
systemic circulation and eliminated by the
body metabolism.
(b) Insoluble, remains in the lungs and are the
main cause of pneumoconiosis
 Factors
effecting the hazardous
effect of dust on the lungs:
a)
b)
c)
d)
e)
Chemical composition.
Fineness.
Concentration of dust in the air.
Period of exposure.
Health status of the exposed person.

So the threshold limit values for different
dust are different.

And the superimposed infection e.g. T.B
influence the pattern of pneumoconiosis.
 The
important dust diseases:

Silicosis, Anthracosis, Byssinosis,
Bagassosis, Asbestosis, Farmer’s lung.

As no cure for pneumoconiosis is known it is
essential to prevent these diseases from
arising.
SILICOSIS

Cased by inhalation of dust containing free
silica or silicon dioxide (sio2 ).

It is a major cause of permanent disability
and mortality.

The hazard found in different industries e.g.:
mining industries (gold, coal, mica, silver,
lead, zinc, manganese and other metals).

Pottery and ceramic industry.

Sand blasting, metal grinding, building and
construction work.

Iron and steel industry and several others.

The incubation period may vary from a few
months up to 6 years of exposure depending
upon the above factors
 Pathology:

The particles are ingested by the phagocytes
which accumulate and block the lymph
channels. Silicosis is characterized by a
dense nodular fibrosis, the nodules ranging
from 3-4 mm in diameter.
 Clinical
picture:
Insidious onset
 Some of the early manifestation of the
disease are:
 Irritant coughs, dyspnoea on exertion, pain
in the chest
 With more advanced disease, impairment of
the total lung capacity (TLC) is commonly
present.


X-ray of the chest shows "snow – storm"
appearance in the lung fields.

The disease is progressive and the patients
are prone to pulmonary T.B a condition
called silicotuberculosis.
This chest x-ray shows stage II coal worker's pneumoconiosis (CWP). There are
diffuse, small light areas on both sides of the lungs. Other diseases that may explain
these x-ray findings include simple silicosis, disseminated tuberculosis, metastatic lung
cancer, and other diffuse, infiltrative pulmonary diseases.
 Treatment:

No effective treatment for silicosis.

Fibrotic changes that have already taken
place cannot be reversed.
 The
only way for control is by:
a)
Rigorous dust control measures e.g.
substitution, complete enclosure, isolation,
hydro lasting, good house- keeping, personal
practice measures.
b)
Regular physical examination of workers.
ANTHRACOSIS
Also called: (coal worker‘s pneumoconiosis,
black lung disease, miner’s pneumoconiosis)
 It is due to coal dust.
 It is of two general phases:
 The first phase labeled simple pneumoconiosis
which is associated with little ventilatory
impairment.
 It needs about 12 years of exposure to develop.


The second phase is characterized by
progressing massive fibrosis (PMF) which
causes severe respiratory disability and
frequently results in death.

It may develop without further exposure.

The risk of death among coal miners is
nearly twice as the general population.
ASBESTOSIS

Asbestos is the commercial name for certain
types of fibrous materials, they are silicates of
varying composition, the silica is combined with
such bases as, magnesium, iron, calcium,
sodium and aluminum.

asbestos fiber are usually from 20 to 500µ in
length and 0.5 to 50µ in diameter.

Asbestos enters the body by inhalation and
deposited in the alveoli, the fibers are
insoluble causes pulmonary fibrosis leading to
respiratory insufficiency and death, carcinoma
of the bronchus, mesothelioma of the pleura
or peritoneum and cancer of the GIT.

The incubation period is 5-10 years of
exposure.

The fibrosis in asbestosis is due to mechanical
irritation and is peri-bronchial, diffuse in
character and basal in location in contrast to
silicosis in which the fibrosis is nodular and
present in the upper part of the lungs.

Clinically there is dyspnoea, later in the
diseases there is clubbing of fingers cardiac
distress and cyanosis.

The sputum shows (asbestos bodies) which
are asbestos fibers coated with fibrin.

X-ray of the chest shows ground-glass
appearance in the lower two thirds of the lung
fields.

The disease when established is progressive
even after removal of the worker from contact.
 The
preventive measures:
1. Use of safer types of asbestos (chrysolite
and amosite).
2. Rigorous dust control.
3. Periodic examination of workers.
BYSSINOSIS

It is due to inhalation of cotton fiber dust over
long period of time.

The symptoms are chronic cough and
progressive dyspnoea.

Ending in chronic bronchitis and emphysema.
BAGASSOSIS

Due to inhalation of bagasse(sugar-cane
dust).

The symptoms consist of breathlessness,
cough, haemoptysis and slight fever.

Initially there is acute diffuse bronchiolitis,
also there is impairment of pulmonary
function.

If treated early, there is resolution of the acute
inflammatory condition of the lung, it left
untreated, There is diffuse fibrosis,
emphysema and bronchiectasis.
 Preventive
1.
Measures:
Dust control:
To suppress dust by wet process, enclosed
apparatus, exhaust ventilation etc.
2. Personal protection:
Masks or respirators with filters or with oxygen or
air supply.
3. Medical control:
Initial examination and periodical check-ups.
4. Bagasse control:
By keeping moisture above 20%.
FARMERS ‘ LUNG
Due to inhalation of mouldy hay or grain dust.
 Bacteria and fungi grow rapidly when moisture
in grain dust or hay is over 30%.
 The acute illness is characterized by general
and respiratory symptoms and physical signs.
 repeated attacks cause pulmonary fibrosis and
pulmonary damage and corpulmonale.
