1. Occupational Medicine Specialist
Dr. Alireza Safaeian
Occupational Medicine Specialist

2. Occupational lung diseases
Occupational lung diseases are a broad group of diagnoses caused by the inhalation of dusts, chemicals, or proteins
The severity of the disease is related to the material inhaled and the intensity and duration of the exposure.
Even individuals who do not work in the industry can develop occupational disease through indirect exposure.
These diseases have been documented as far back as ancient Greece and Rome

3. Occupational lung diseases
Pneumoconiosis
Occupational Asthma
COPD
H.P. (Hypersensitivity pneumonitis)
Occupational Respiratory Infections
Occupational lung cancers

4. Pneumoconiosis
A group of interstitial lung diseases caused by the inhalation of certain dusts and the lung tissue’s reaction to the dust.
There is a long delay (up to ten years or more) between exposure and onset of disease,

5. Pneumoconiosis The main types: Other forms pneumoconioses Asbestosis
can be caused by inhaling dusts containing :
Aluminum
Antimony
Barium
Graphite
Iron
Kaolin
Mica
Talc
mixed-dust pneumoconiosis
Byssinosis: exposure to cotton dust
Asbestosis
Silicosis
coal workers’ pneumoconiosis

6. Asbestosis

7. Introduction (Asbestos)
Naturally occurring material
Hydrate silicate with variable magnesium content
Fibrous structure: length to width more than 3/1

8. Actinolite, Amosite, Anthophyllite, Crocidolite, Richterite, Tremolite
Types of Asbestos
Serpentine
(93% of commercial use)
Amphibole
(7% of commercial use)
Chrysotile
Actinolite, Amosite, Anthophyllite, Crocidolite, Richterite, Tremolite

9. Types of Asbestos Others: Chrysotile - “White asbestos”
The most common commercial forms:
Chrysotile - “White asbestos”
Amosite - “Brown asbestos”
Crocidolite - “Blue asbestos”
Tremolite (sometimes found in vermiculite)
Actinolite
Anthophyllite
All types of asbestos have been associated with all of the malignant and non-malignant conditions,

10. Properties of Asbestos
Naturally occurring fibrous minerals
Good tensile strength
Flexible
Heat resistant
Electrical resistance
Good insulation
Chemical resistant
Resistant to breakdown by acid, alkali, water, heat, and flame
Asbestos ore
Because of these unique properties, asbestos was used extensively in variety of products.
Asbestos fibers

11. Uses of Asbestos in industry
Asbestos has been used for centuries, but greatly increased during and after World War II in ship insulation .
Insulation
Textiles
Cements
Friction materials (brake linings, Clutch casings)
Construction
mining & milling,
shipyard
sheet metal worker
plumbers & pipefitters
Steamfitter
plasterboard worker
transport
Acoustic products
Automobile undercoating
Floor tiles
Fire-fighting suits
Fireproof paints
Roofing materials
Ropes
Steam pipe material

12. Examples of Uses of Asbestos
Sheet vinyl containing asbestos
Sprayed-on fireproofing material
These products may be found in homes and buildings constructed before 1981.
Vinyl asbestos flooring

13. Damaged asbestos pipe insulation
This damaged pipe insulation is a health hazard to persons working around it, handling it or removing it. Asbestos fibers are visible on the torn edges.

14. Asbestos Roofing Material

15. Cement-asbestos pipe (Transite)
Cement-asbestos pipe, sometimes called Transite, was used underground and above ground in years past and may show up in pipe replacement jobs, building demolition jobs or excavations.

16. Asbestos Ceiling Tile
Tile close-up

17. Asbestos shingles and siding
Found in older houses – not to be confused with newer asbestos-free cement siding. There is little hazard unless disturbed. The top right hand picture shows a siding replacement job with broken green asbestos shingles which would have released dust and fibers into the air if done incorrectly.
Removal done correctly

20. Exposure history Onset & latency
-more than 20 years for fibrosis & plaque
-several years for pleural thickening
Duration
-more than 6 months for fibrosis & plaque
-shorter for pleural thickening

21. Exposure history Intensity direct exposure : insulator
bystander exposure : sheet-metal worker
indirect exposure : family members

22. Exposure limit OSHA (PEL) : 0.1 fiber /cm 3 (TWA)
Short time exposure : 1 fiber / cm3
Reducing in asbestos usage from 1970 in USA
Asbestos ban from 1989 by EPA

24. Asbestos-related disease
Non-malignant
Malignant
Parenchymal Asbestosis
Asbestos-Related Pleural Abnormalities
Lung Carcinoma
mesothelioma

25. Parenchymal Asbestosis
Diffuse interstitial fibrosis with:
Restrictive pattern of disease on pulmonary function testing (but can see mixed pattern)
Impaired gas exchange
Progressive exertional dyspnea
Radiographic changes: >10 years
Latency period: more than 20 years

26. Chest Radiograph Findings: Parenchymal Asbestosis
Small, irregular oval opacities
Interstitial fibrosis
“Shaggy heart sign”
List of certified B Readers:

27. Asbestosis. Asbestosis and asbestos-related pleural disease in a 70-year-old man. Posteroanterior chest radiograph reveals prominent linear opacities at both bases, with obscuring of the cardiac borders and diaphragm. The thick, linear band at the right lateral base likely represents the subpleural, curvilinear opacities observed on high-resolution CT scans.

29. Asbestosis. High-resolution CT scan more inferiorly reveals subpleural, curvilinear opacities bilaterally (white arrows) and thickened interstitial lines (black arrows).

30. Asbestosis. High-resolution CT scan through the lower lung zone nicely demonstrates thickened septal lines (white arrows) and small, rounded, subpleural, intralobular opacities (black arrow). Also note the calcified diaphragmatic pleural plaque on the left.

31. Asbestos-Related Pleural Abnormalities
Four types of abnormalities:
Pleural plaques
Benign asbestos pleural effusions
Diffuse pleural thickening
Rounded atelectasis
Mostly asymptomatic, though some can cause dyspnea or cough
Latency periods: years (shorter latency is for pleural effusion)

32. Chest Radiograph Findings: Asbestos-Related Pleural Abnormalities
Pleural plaques
Areas of pleural thickening
Sometimes with calcification
Pleural effusions
Diffuse pleural thickening
Lobulated prominence of pleura adjacent to thoracic margin
(over ¼ of chest wall)
Interlobar tissue thickening
Rounded atelectasis
Rounded pleural mass
Bands of lung tissue radiating outwards

33. Lung Carcinoma Risk depends on: Latency period: 20-40 years
Level, frequency, and duration of exposure
Time elapsed since exposure
Age at time of exposure
Smoking history (synergistic)
Individual susceptibility factors (under investigation)
Latency period: years

34. Chest Radiograph Findings: Mesothelioma
Pleural effusions
Pleural mass
Diffuse pleural
thickening

35. Clinical Presentation
Disease
Signs and Symptoms
Parenchymal Asbestosis
Insidious onset of dyspnea on exertion
Fatigue
Asbestos-Related
Pleural Abnormalities
Usually: None
Sometimes: Progressive dyspnea and intermittent chest pain (depending on the type of pleural abnormality)
Lung Cancer
Usually: None (until later stages)
Sometimes: Fatigue, weight loss, or chest pain
Mesothelioma
Sometimes: Dyspnea, chest pain, and fatigue

36. Physical Examination Focus on lungs, heart, digits, and extremities
Pulmonary auscultation to detect bibasilar inspiratory rales (not always present)
Observation of other signs, such as clubbing of the fingers and cyanosis

37. HRCT
Indication: Equivocal CXR , significant symptom with unremarkable CXR , pleural obscuring abnormalities
-Prone views for assess basilar, posterior and subpleural regions
Septal thickening : intra lobular or interlobular
Subpleural lines and opacities
Parenchymal bands
Ground-glass
honeycombing

38. Diagnosis ILO classification: 1/0 or greater on CXR
Based on : Exposure + Clinic + CXR + PFT
Exposure : sufficient intensity , 6months duration , 20 years latency
ILO classification: 1/0 or greater on CXR
PFT : restrictive or mixed
HRCT
Biopsy : exclusion of malignancy

39. Management
Unfavorable response to corticosteroids and immunosupressive agents : case-by-case in progressive alveolitis
Therapy is supportive :
-bronchodilator , ipratropium , inhaled steroid
-oxygen
-treatment of infections

40. Management -stopping of exposure -Influenza and pneumococcal vaccines
-Smoking cessation

41. Medical surveillance No clear evidence for the benefit
Spiral CT : early detection against risk and cost of evaluating false positive

42. Medical surveillance Exposed worker with normal CXR & PFT :
CXR and PFT every 2 to 5 years (based on the latency period)
ILO 1 or sign or symptom :
annual CXR and full PFT every 2 years
Isolated pleural thickening :
CXR and PFT biannually (more frequently if presence of increasing symptoms or pleural involvement)

43. Silicosis

44. Introduction:
Most common pneumoconiosis in world (occupational exposure to crystalline silica)
*quartz,cristobalite,tridymite,…
OSHA(PEL) :100 μg/m3

45. High risk trade for Crystalline Silica Exposures
Tunneling
Hard-rock mining
Sandblasting
Quarrying
Stonecutting
Foundry work
Ceramics work
Abrasive work
Brick making
Paint making
Polishing
Stone drilling
Well drilling

46. Crystalline Silica Exposures
If you work near dust clouds like the ones in these photos, you might be exposed to silica. You may be exposed even when dust is not visible.

47. Silica-induced diseases
Chronic bronchitis
Emphysema
Silicosis
Tuberculosis
Lung cancer
Collagen vascular diseases

48. Silicosis Chronic simple ( classic ) silicosis
Depends on exposure intensity and quartz content of dust
Chronic simple ( classic ) silicosis
Chronic complicated ( PMF ) silicosis
Accelerated silicosis
Acute silicosis

49. Simple silicosis:
No symptoms or Breathlessness Dyspnea(initially with exercise), Cough with or without sputum
P/E: often normal but may rales or decreased breath sound.
CXR: Rounded opacities(1-10mm)
*Eggshell calcification
PFT: often normal but may restrictive(mainly) obstructive or mixed pattern.

51. Exposure Moderate exposure at least 10 yr exposure
less than 30% quartz

52. Progressive massive fibrosis:
Cough / exertional dyspnea to respiratory failure.
P/E: decrease respiratory sounds.
CXR: Rounded opacities(>10mm)
Pulmonary impairment

56. Accelerated silicosis:
Time from exposure to X-Ray & PFT change is much shorter.
Moderate-high exposure to silica with 40-80% quartz.
Latent period: 2-5 yr ( from exposure to presentation)
Rapid progression to progressive massive fibrosis.

57. Acute silicosis (silicoproteinosis)
Short duration and high concentration.(Tunneling, abrasive blasting, …)
Latent period: few months-3yrs after exposure
Symptoms: rapidly progressive dyspnea. Respiratory failure to death.
P/E: crackles (alveolar & airway fluid)
CXR:
Diffuse perihilar alveolar filling( consolidation, A type of alveolar proteinosis.)
Ground-glass opacities
PFT: Progressive restrictive impairment
Fatal 1-2 yrs after initiation of symptoms

60. Diagnosis
1)History of silica exposure that sufficient to cause this illness.
2)Chest radiograph features consistent with silicosis.
3)Absence of other illness that mimic silicosis.

61. WHO recommendation: CXR at baseline after 2-3 years of exposure
then every 2-5 years.
Spirometry & questionnaire
then annually or at the same frequency as CXR.

62. Associated illnesses:
Mycobacterial infections (20-fold increased risk in silicosis , 3-fold increased risk in silica exposure without silicosis)
PPD + / Isoniazid /at least 1 year
Lung cancer : group 1 IARC
Connective tissue disease (Caplan’s syndrome)
Renal disease: Glomerulonephritis, nephrotic syndrome, ESRD
Silicotic Lesions (liver, spleen, BM, lymph nodes)

63. Prevention: Engineering intervention Administrative controls
Respiratory protective devices

64. Example of a Combination of Controls
Enclosure of the process and local exhaust ventilation in a dental laboratory.
Source: What Dental Technicians Need to Know About Silicosis. NJDHSS.

66. Respiratory protective devices
if other methods are not sufficient
Use Proper Respiratory Protection

67. Example of a Combination of Controls
Sandblaster using proper respiratory protection inside a ventilated booth. Note that the worker is supplied with two separate air lines - one to supply fresh air for the worker to breathe and the other to supply air for sandblasting.
Source: NIOSH Publication No : Silicosis in Sandblasters: A Case Study for Use in U.S. High Schools

68. Treatment Corticosteroid with Isoniazid (acute silicosis, CTD)
Lung lavage
Lung transplant

69. Occupational Asthma

70. Asthma Overview Asthma is an inflammatory disorder of the airways.
When an asthma attack occurs, the muscles surrounding the airways become tight and the lining of the air passages swell.
This reduces the amount of air that can pass by, and can lead to wheezing sounds.
Variable airflow obstruction and/or airway hyper-responsiveness (Reversible obstruction(+/- treatment)
Asthma Overview
Asthma is a chronic disease involving the airways in the lungs. These airways, or bronchial tubes, allow air to come in and out of the lungs.
If you have asthma your airways are always inflamed. They become even more swollen and the muscles around the airways can tighten when something triggers your symptoms. This makes it difficult for air to move in and out of the lungs, causing symptoms such as coughing, wheezing, shortness of breath and/or chest tightness.
For many asthma sufferers, timing of these symptoms is closely related to physical activity. And, some otherwise healthy people can develop asthma symptoms only when exercising. This is called exercise-induced bronchoconstriction (EIB), or exercise-induced asthma (EIA). Staying active is an important way to stay healthy, so asthma shouldn't keep you on the sidelines. Your physician can develop a management plan to keep your symptoms under control before, during and after physicial activity.
People with a family history of allergies or asthma are more prone to developing asthma. Many people with asthma also have allergies. This is called allergic asthma. Occupational asthma is caused by inhaling fumes, gases, dust or other potentially harmful substances while on the job.
Childhood asthma impacts millions of children and their families. In fact, the majority of children who develop asthma do so before the age of five.
There is no cure for asthma, but once it is properly diagnosed and a treatment plan is in place you will be able to manage your condition, and your quality of life will improve.
An allergist / immunologist is the best qualified physician in diagnosing and treating asthma. With the help of your allergist, you can take control of your condition and participate in normal activities.

71. Asthma Symptoms Asthma symptoms vary from person to person
Wheezing (The most common symptom)
Shortness of breath
Chest tightness or pain
Chronic coughing
Trouble sleeping due to coughing or wheezing
Asthma Symptoms & Diagnosis
Asthma Symptoms According to the leading experts in asthma, the symptoms of asthma and best treatment for you or your child may be quite different than for someone else with asthma.
The most common symptom is wheezing. This is a scratchy or whistling sound when you breathe. Other symptoms include: •    Shortness of breath •    Chest tightness or pain •    Chronic coughing •    Trouble sleeping due to coughing or wheezing
Asthma symptoms, also called asthma flare-ups or asthma attacks, are often caused by allergies and exposure to allergens such as pet dander, dust mites, pollen or mold. Non-allergic triggers include smoke, pollution or cold air or changes in weather.
Asthma symptoms may be worse during exercise, when you have a cold or during times of high stress.
Children with asthma may show the same symptoms as adults with asthma: coughing, wheezing and shortness of breath. In some children chronic cough may be the only symptom.
If your child has one or more of these common symptoms, make an appointment with an allergist / immunologist: •    Coughing that is constant or that is made worse by viral infections, happens while your child is asleep, or is triggered by exercise and cold air •    Wheezing or whistling sound when your child exhales •    Shortness of breath or rapid breathing, which may be associated with exercise •    Chest tightness (a young child may say that his chest “hurts” or “feels funny”) •    Fatigue (your child may slow down or stop playing) •    Problems feeding or grunting during feeding (infants) •    Avoiding sports or social activities •    Problems sleeping due to coughing or difficulty breathing
Patterns in asthma symptoms are important and can help your doctor make a diagnosis. Pay attention to when symptoms occur: •    At night or early morning •    During or after exercise •    During certain seasons •    After laughing or crying •    When exposed to common asthma triggers
Asthma Diagnosis An allergist diagnoses asthma by taking a thorough medical history and performing breathing tests to measure how well your lungs work.
One of these tests is called spirometry. You will take a deep breath and blow into a sensor to measure the amount of air your lungs can hold and the speed of the air you inhale or exhale. This test diagnoses asthma severity and measures how well treatment is working.
Many people with asthma also have allergies, so your doctor may perform allergy testing. Treating the underlying allergic triggers for your asthma will help you avoid asthma symptoms.

72. Asthma attack
Most people with asthma have wheezing attacks separated by symptom free periods
Asthma attacks can last minutes to days and can become dangerous if the airflow becomes severely restricted.

73. Asthma attacks caused by:
Allergies and exposure to allergens such as pet dander, dust mites, pollen or mold.
Non-allergic triggers include smoke, pollution or cold air or changes in weather.

74. Occupational Asthma
Occupational factors account for approximately one in six cases of asthma in adults of working age, including new onset or recurrent disease.
(OSHA) reports : estimated 11 million workers in the USA are exposed to at least one of the more than 250 Asthmogen substances.
Occupational factors are associated with up to 15 percent of disabling asthma cases.

75. Work-related asthma
Two distinct categories:
Occupational asthma: induced by exposure in the working environment to airborne dusts, vapors or fumes, in workers
Work-aggravated asthma: pre-existing or coincidental new-onset adult asthma, which is made by occupational exposure.

76. Occupational asthma
Sensitiser-induced occupational asthma: (approximately 90% of cases of occupational asthma)
Irritant-induced occupational asthma
For some agents, both immunological and non-immunological mechanisms can be involved

77. Occupational asthma Irritant OA Sensitizer OA
Develops after a single, very high exposure to an irritant chemicals
Manifest asthma symptoms within 24 hours of the exposure
Improve over time and may go away entirely (3 months)
If symptoms persist beyond 6 months persistent problems are possible.
Sensitisation or becoming allergic to a specific chemical agent in the workplace over a Period of time
Latency period (several weeks or as long as several years)
The period of greatest risk is the first two years of exposure

78. workers who are at increased risk of developing occupational asthma
Bakers
Detergent manufacturers
Drug manufacturers
Farmers
Grain elevator workers
Laboratory workers (especially those working with laboratory animals)
Metal workers
Millers
Plastics workers
Woodworkers

79. After sensitization
The smallest amounts of exposure will produce symptoms.
OEL does not protect the person already sensitized.
Symptoms can happen immediately after the worker starts working with the substance or soon afterwards.
The symptoms typically improve when the worker is away from the workplace on days off or holidays.

80. Respiratory sensitizers

81. Natural history of occupational asthma
If exposure to the causative agent ceases Completely: the condition will nearly always improve.
Within the first two years: complete recovery is usual
The longer the exposure continues: tendency for the condition to get worse, and less likely to be a complete recovery
a cessation of exposure is nearly always of benefit.
If exposure to the causative agent ceases completely, the condition will nearly always improve. If this
happens within the first two years of the development of the condition then complete recovery is usual.
The longer the exposure continues however, not alone is there a tendency for the condition to get worse,
but the less likely it is that there will be a complete recovery although a cessation of exposure is nearly
always of benefit. For these reasons identifying a case of occupational asthma as early as possible is of
paramount importance, and hence the reason for health surveillance.

82. Prognosis Generally, occupational asthma has a poor prognosis
approximately 2/3 of workers never achieving full symptomatic recovery
Approximately 3/4 having persistent non-specific bronchial hyper-responsiveness.
Approximately 1/3 of workers with occupational asthma are unemployed up to six years after diagnosis

83. How is exposure prevented and controlled?
Engineering control (replace, segregate the work, enclose the process, partially enclose the process, local exhaust ventilation)
If after there is still exposure, provide suitable personal respiratory protection to workers
Stop using the sensitiser by replacing with a safer alternative if available
Otherwise, segregate the work so to minimise the amount of workers exposed
Totally enclose the process
If this is not possible, partially enclose the process and provide local exhaust ventilation
If after carrying out the above control measures, there is still exposure, provide suitable personal
respiratory protection to workers
If there is dependence on personal protective equipment (PPE), this equipment must be suitable for
the task and work effectively. Fit testing is usually necessary for example
Where substitution is not possible and there is still a risk of exposure despite the implementation of
control measures, health surveillance must be provided.

84. Pre Employment Medical assessment
Pre employment health questionnaire
Spirometry or Pulmonary function test (PFT)
Medical examination
A previous history of asthma, significant atopy (or allergy) or an obstructive pattern on PFT may increase that individuals risk to getting more severe asthma.

85. Routine Health Surveillance
3 months and 12 months after job commencement and annually thereafter.
The respiratory questionnaire should be completed again and results compared to pre employment ones.
Spirometry or Pulmonary function test (PFT)
Medical examination

86. occupational asthma evaluation
The first step
The next step
confirmation of the diagnosis of asthma.
history and clinical examination
objective tests (serial peak flowmetry, spirometry and Bronchial Challenge tests Metacholine or Histamine)
Determination of its potential to work
A history of symptoms being related to work is suggestive but not conclusive
Potential sensitisers in the workplace should be identified
objective tests (serial peak flowmetry, spirometry and Bronchial Challenge tests Metacholine or Histamine, blood tests and/or Prick tests)
A specific Bronchial Challenge test is usually considered to be the Gold Standard in the diagnosis of occupational asthma.

87. Diagnosis
Spirometry (base and serial) for work related ↓10% of FEV1 before and after.(across shift)
Methacholine or histamin challenge test after holydays associated with 3time ↑Pc20.
P.E.F serial (the best test for O.A).
Immunological tests(specific IgE→HMW &platinum)
FeNO, sputum induced analysis(4-6 h and Eos)
C.X.R

88. What is a peak flow meter?

89. زلال باش .... ،‌ زلال باش .... ،
فرقي نمي كند كه گودال كوچك آبي باشي ، يا درياي بيكران ،
زلال كه باشي ، آسمان در توست