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Byssinosis
Emily A Kamel
Prof of Occupational and Environmental Health
Dept of Public Health and Community Medicine
Occupational Lung disease
Pneumo-conioses
Pneumo- (Lungs)
+
Koniosis (Latin for dust)
=
Dusty Lungs
Pneumo-conioses
Inorganic Dust
Organic Dust
Silicosis
Bronchial Asthma
Asbestosis
Byssinosis
Coal Workers
Pneumo-coniosis
Hypersensitivity
Pneumonitis
Examples of hazardous organic dust
Agriculture dusts
– Handling of grain, hay or other crops
‫غبار الحبوب و القش و المحاصيل‬
‫األخرى‬
– Sugar-cane processing ‫غبار قصب السكر‬
– Greenhouses ‫الصوبة‬
– Silos ‫صوامع القمح و الحبوب‬
Examples of hazardous organic dust
Animals dusts
– Farm animals confinement buildings.
–Poultry houses and processing plants.
–Laboratory animals buildings.
Examples of hazardous organic dust
Industry dusts
– Vegetable fibre processing as cotton, flax,
hemp, jute, sisal in ----- Textile industries.
– Wood processing in ----- Furniture industries.
– Wheat flour handling in ---- Bakeries.
– Organism handling in ---- Biotechnology industry.
Sources of Organic Dusts
• Agriculture
• Animals handling
• Industry based on organic dusts
Exposure Parameters
• Type of dust
• Duration of exposure
• Intensity of exposure
• Use of PPE
Byssinosis
Example of Occupational Lung Disease
Byssinosis results from breathing in the
dust from raw cotton processing while in
the workplace.
• Cotton is a soft, natural,
vegetable fiber
• The boll of the cotton
plant.
• The chemical composition of cotton is almost
pure cellulose, but it grows in a complex
biologic milieu within the boll ,
• It is subjected to various environmental
contaminants after the boll opens to the
environment when it matures.
Case Definition
Asthma-like disease characterized by chest
tightness, cough, and shortness of breath,
on one or more days of the working week.
In early stages, it is reversible by bronchodilators
and
eliminating
from
exposure.
In late stages,
it is irreversible causing
permanent damage to the lungs with symptoms
similar
to
COPD.
Broader and more complex than other
forms of asthma.
A mixture of conditions ranging from
true asthma to exacerbated chronic
bronchitis.
It results from breathing in the dust from
raw cotton processing.
High-risk groups
Workers in cotton mills and textile Industries
handling :
Raw cotton
Un-processed cotton
Coarse cotton
Organic fibres
Exposure to cotton dust
•
•
•
•
•
Ginning ‫الحلج‬
Opening and mixing ‫فتح الباالت و الخلط‬
Blowing ‫ضرب و نفخ القطن‬
Carding ‫التمشيط‬
Spinning ‫الغزل‬
Cause / Pathogenesis
• Cotton fibres ?
• Bacterial endotoxin carried by the
dust after it has been released when
cells of bacteria (E coli) populating
the cotton die and disintegrate.
Pathology
Airways inflammation
Chronic bronchitis
COPD
No pulmonary fibrosis
There is now uniform evidence that
bacterial endotoxins are the causative
agent for airways inflammation.
Dose-response relationships have been
described and the typical symptoms have
been induced by inhalation of purified
endotoxin (Rylander et al. 1989; Michel et
al. 1995).
Although this does not exclude the
possibility that other agents could
contribute to the pathogenesis, endotoxins
can serve as markers for disease risk.
Clinical Picture
• Typical Byssinosis, similar to asthma,
does not appear until after several years
of regular exposure.
• The symptoms often surface at the first
shift of first day of working week
(Monday or Saturday).
Symptoms
• Chest tightness (Classic symptom)
• Cough
• Shortness of breath
Onset Symptoms of Byssinosis
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Tightness
Well
Well
Well
Well
Well
Well
Tightness
Well
Well
Well
Well
Well
Well
Tightness
Well
Well
Well
Well
Well
Well
Tightness
Well
Well
Well
Well
Well
Well
Early Course of Byssinosis
Monday
Tuesday
Wednesday
Thursday
Tightness
Friday
Saturday
Sunday
Tightness
Well
Well
Well
Well
Well
Tightness
Tightness
Well
Well
Well
Well
Well
Tightness
Well
Well
Well
Well
Well
Well
Tightness
Well
Well
Well
Well
Well
Well
• Symptoms develop on the first day of work
after a weekend or vacation and diminish or
disappear by the end of the week.
• With repeated exposure over a period of years,
chest tightness tends to persist through
midweek and occasionally to the end of the
week or as long as the person continues to
work.
• This typical temporal pattern distinguishes
byssinosis from asthma.
A subjective feeling of chest tightness, most
common on Mondays, is the classical
symptom of cotton dust exposure (Schilling
et al. 1955).
It is not, however, a feature unique to
cotton dust exposure as it appears also
among persons working with other kinds of
organic dusts (Donham et al. 1989).
How is Byssinosis detected /diagnosed?
• A detailed medical history including an
occupational health history .
• Physical examination
• Pulmonary function tests
• Chest X-ray
FEV1 - FVC
Always ask the patient about his
Occupation ?
Pulmonary function tests
Typical airflow obstruction and a
reduction in ventilatory capacity,
especially if measured at the start and
end of a first work shift.
↓ FEV 1
↓ FEV1/ FVC
The diagnosis of byssinosis is classically made
using questionnaires with the specific question
“Does your chest feel tight, and if so, on which
day of the week?”.
Persons with Monday morning chest tightness
are classified as byssinotics according to a
scheme suggested by Schilling (1956).
Spirometry can be performed, and, according to
the different combinations of chest tightness
and decrease in FEV1, the diagnostic scheme has
evolved.
Diagnostic criteria for byssinosis
• Grade 1/2. Chest tightness on the first day of
some working weeks
• Grade 1. Chest tightness on the first day of every
working week
• Grade 2. Chest tightness on the first and other days
of the working week
• Grade 3. Grade 2 symptoms accompanied by
evidence of permanent disability in the form of
diminished effort intolerance and/or reduced
ventilatory capacity
Treatment
• Stop being exposed to the dust.
• Change jobs to avoid further exposure.
• Medications prescribed include :
Bronchodilators - Corticosteroids
• Chronic byssinosis treated with respiratory
treatments including nebulizers.
Treatment
• Home oxygen therapy if blood oxygen
levels are low.
• Quit smoking to prevent further damage
to lungs.
• Physical exercise programs
• Breathing exercises
Although Occupational lung
diseases may not be cured,
they can be prevented.
Basic Principle
Eliminate Hazard OR Risk
which means
Eliminate Hazard OR Exposure
Prevention
Basic Principles
 Product substitute.
Environmental
 Good Ventilation.
 Worker Protection.
---------------------------------------------- Medical surveillance with transfer policies
for affected workers.
Medical
Environmental Measures
• Synthetic or semi-synthetic fibres be used.
• Cotton with low level of bacterial contamination
be used (Clean cotton).
• Reducing dust levels in the factory by improving
ventilation or machinery.
• Wearing personal protective equipment as face
masks to limit exposure.
• Environmental monitoring.
NIOSH-Approved N95 Particulate
Filtering Facepiece Respirators
HSE – WEL
Workplace Exposure Limit
for cotton dust
0.5 mg m−3 TWA*
of collected dust less fly.
* Time Weighted Average
For endotoxins,
it has been suggested that a level of
200 ng/m3 is the threshold for toxic
pneumonitis,
100 to 200 ng/m3 for acute airways
constriction over the workshift
and 10 ng/m3 for airways inflammation
(Rylander and Jacobs 1997).
Medical measures
Pre-employment clinical examination:
• Educate workers about on-the-job hazards
(informed workers).
• Advise them to quit smoking if working with
raw cotton.
• A spirogram reading is recorded as baseline
record.
• At periodic clinical examination: the
worker is asked about symptomatology and
worker’s spirogram is compared to his baseline
reading to detect any obstruction early enough to
transfer him to non-dusty job.
• If a worker complains in between periodic
examinations , the same is done to him and the
case is investigated and recorded (Medical
Surveillance).
Main question in Taking Clinical
History in Byssinosis
Does your chest feel tight, and if so, on
which day of the working week?
PubMed Health.com
Thank You
Carding is straightening or smoothing of
raw fibers in a parallel fashion.
Flax is ‫الكتان‬
Hemp is ‫القنب‬
Importance of lung as portal of entry
for noxious agents
The repeated branching of the airways from
tracheal bifurcation to alveoli - greatly
increasing the surface area of the respiratory
mucosae - while reducing the rate of air flow.
Thus, the 300 million alveoli offer a surface
area of some 70 meter square for gas
exchange while no alveolus exceeds 0.1 mm in
diameter.