byssinosis emily a kamel prof of occupational and environmental health dept of public health and...
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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
Asbestosis
Coal Workers Pneumo-coniosis
Bronchial Asthma
Byssinosis
Hypersensitivity Pneumonitis
Examples of hazardous organic dust
Agriculture dusts
– Handling of grain, hay or other cropsاألخرى المحاصيل و القش و الحبوب غبار
– Sugar-cane processing السكر قصب غبار
– Greenhouses الصوبة
– Silos الحبوب و القمح صوامع
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.
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.
Case Definition
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
• Ginning الحلج • Opening and mixing الخلط و الباالت فتح• Blowing القطن نفخ و ضرب• Carding التمشيط • Spinning الغزل
Exposure to cotton dust
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.
Airways inflammation
Chronic bronchitis
COPD
No pulmonary fibrosis
Pathology
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.
• 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).
Clinical Picture
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
Monday Tuesday Wednesday Thursday Friday Saturday Sunday
Tightness
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
Early Course of Byssinosis
• 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 FEV1 - FVC
• Chest X-ray
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
PreventionBasic Principles
Product substitute. Environmental
Good Ventilation.
Worker Protection. -----------------------------------------------Medical surveillance with transfer
policies for affected workers. Medical
• 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.
Environmental Measures
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).
Does your chest feel tight, and if so, on which day of the working week?
Main question in Taking Clinical History in Byssinosis
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.