1. Overview of Occupational disease
Case Studies
DrWayne Ramgoolam
HeadOccupational Health Unit
SouthWest Regional Health Authority

2. Worldwide, occupational diseases continue to be the leading
cause of work-related deaths.
 2.02 million people die each year from work-related diseases.
 321,000 people die each year from occupational accidents.
 160 million non-fatal work-related diseases per year.
 317 million non –fatal occupational accidents per year.
This means that:
 Every 15 seconds, a worker dies from a work-related accident or
disease.
 Every 15 seconds, 151 workers have a work-related accident

3.  Overview of Occupational Disease
 Definition
 Historical perspective
 Classification
 Management
 Prevention
 Case Studies

4.  Any disease contracted as a result of an exposure to risk factors arising from
work activity.
Protocol of 2002 to the Occupational Safety and Health Convention, 1981 (No.
155)
 Diseases known to arise out of the exposure to substances and dangerous
conditions in processes, trades or occupations
ILO Employment Injury Benefits Recommendation, 1964 (No. 121), Paragraph
6(1)
 Two main elements are present in the definition of an occupational disease:
1. the causal relationship between exposure in a specific working environment or
work activity and a specific disease
2. the fact that the disease occurs among a group of exposed persons with a
frequency above the average morbidity of the rest of the population.

5. BIRTH OF OCCUPATIONAL MEDICINE

6.  Considered to be the
father of occupational
and industrial medicine
 Diseases ofWorkers
(De Morbis Artificum
Diatriba)
First edition - 1700
Second edition - 1713

7.  published the first systematic study connecting the
environmental hazards of specific professions to disease
Example: lead exposure in potters and painters
 His book on occupational diseases outlined the health
hazards and other disease-causative agents
encountered by workers in 52 occupations.
 This was one of the founding and seminal works of
occupational medicine and played a substantial role in
its development.
 It was he who proposed that physicians should extend
the list of questions that Hippocrates recommended
they ask their patients by adding, "What is your trade?"

8.  Chimney Sweepers’
Cancer of the scrotum
 first to associate cancer
with occupational
exposure (1775)

9.  In what represents one of the earliest
epidemiologic studies (or studies of the
occurrence and causes of disease), Pott observed
that chimney sweeps in England had higher
rates of scrotal cancer than the rest of the
population.
 In doing their jobs, the chimney sweeps often
had to climb into chimneys and suffered
prolonged exposure to soot containing
polycyclic aromatic hydrocarbons

10.  founder of occupational
medicine in the U.S. and
the first woman on the
faculty of Harvard
Medical School
 took a leading role in two
major environmental
controversies of the
1920s involving leaded
gasoline and radium dial
painters (known as the
“radium girls”).

12.  The Radium Girls were female factory workers who
contracted radiation poisoning from painting watch dials
with glow-in-the-dark paint at the United States Radium
factory in Orange, New Jersey around 1917.
 The women, who had been told the paint was harmless,
ingested deadly amounts of radium by licking their
paintbrushes to sharpen them; some also painted their
fingernails and teeth with the glowing substance.
 Five of the women challenged their employer in a case
that established the right of individual workers who
contract occupational diseases to sue their employers
 The litigation and media sensation surrounding the case
established legal precedents and triggered the enactment
of regulations governing labour safety standards

13. 19th Century
 Statutory medical service for factory workers
▪ Factory Inspectors
▪ Medical certification for children
▪ Certifying Surgeons
▪ Workers with exposure to lead, white phosphorus, explosives, rubber – periodic
exams
▪ Notification of industrial disease – lead, phosphorus, arsenic, anthrax
 Common law – employer liable if negligent
 WC legislation in Europe
20th Century
 WC legislation in North America
 Development of government agencies and professional associations
 InternationalCongress on workers’ diseases in Milan - 1906 - ICOH

14.  Skin cancer – sunlight, tar, oils, soot, arsenic
 Silicosis – quarries, mines, stone cutting
 Coal workers’ pneumoconiosis
 Lead poisoning
 Mercury poisoning
 Bladder cancer – organic dyes
 Lung cancer –
chrome, nickel, radon, asbestos

16.  Occupational diseases caused by exposure to agents
arising from work activities (Hazards)
 Diseases caused by chemical agents
Diseases caused by physical agents
Diseases caused by biological agents
 Occupational diseases by target organ systems
 Occupational respiratory diseases
Occupational skin diseases
Occupational musculo-skeletal disorders
Mental and behavioural disorders
 Occupational cancer
 Cancer caused by the following agents
 Other diseases

17.  Physical
 Chemical
 Biological
 Mechanical &
Ergonomic
 Psychosocial

18. HAZARD EXAMPLES
Physical Noise,Vibration, Radiation, Heat
Chemical Dusts, Metals, Solvents, Gases
Biological Human tissue & bodily fluids (blood)
Microbial pathogens
Animal and animal products
Ergonomic/Mechanical Lifting & handling
Poor posture
Repetition
Poor equipment & workplace design
Psychosocial Organizational Psychosocial Factors
High demand
Low control
Violence and aggression
Lone working
Shift work
Night work
Long working hours

19. Target organ systems
 Occupational infections
 Respiratory & Cardiovascular disorders
 Skin disorders
 Musculoskeletal disorders
 GI & UrinaryTract disorders
 Eye disorders
 Neurological disorders
 Psychiatric disorders
 Reproductive disorders
 Haematological disorders
 Medically unexplained occupational disorders

20. Occupational Infections Respiratory & Cardiovascular
Blood borne viruses
Hep B,C
HIV
Meningococcal
Tuberculosis
Legionnaires
Tetanus
Influenza
Zoonoses
Anthrax (cows,sheep)
Glanders (horses, cats, dogs)
Brucellosis (cows, sheep, goats, pigs)
Lyme disease (deer)
Q fever (sheep, cows goats)
Orf (sheef)
Occupational Asthma
COPD
Hypersensitivity pneumonitis
Farmer’s lung (mouldy hay, grain, straw)
Bird fanciers lung (bird excreta)
Mushroom workers lung (mushroom compost)
Bagassosis (bagasse from sugar cane
Malt workers lung (mouldy barley)
Ventilation pneumonitis (water in AC systems)
Metal fume fever
Pneumoconioses
Coal workers
Asbestosis
Silicosis
Lung cancer
Pleural disorders (mesothelioma)
Coronary heart disease

21. Skin Musculoskeletal GI & Urinary Eye Neurological
Dermatitis
Contact urticaria
Skin cancer
Pigmentation
disorders
Photodermatitis
scleroderma
Lower back pain
WRULD’S
Carpal tunnel
Tenosynovitis
capsulitis
Hepatic
Angiosarcoma
Cirrhosis
Hepatotoxicity
GI cancers
Renal failure
Bladder cancer
Conjunctivitis
Cataract
Retinal burns
Brain cancer
Parkinsonism
Organophosphate
HAVS
NIHL
Psychiatric Reproductive Haematological Unexplained
Psychoses
Stress
PTSD
Impaired fertility
Adverse pregnancy
Bone Marrow aplasia
Methaemoglobinaemia
Haemolysis
Haematological malignancies
Sick building
syndrome

23.  Diagnosis
 Clinical investigation
▪ Occupational history (plus routine history)
▪ Identify occupational risk factors for disease / patterns of exposure
▪ Understand job demands
▪ Physical examination
▪ Investigations (functional test of target organ)
▪ Audiometry, spirometry, blood & radiological investigations
 Workplace investigation
▪ Review job description
▪ Review job task analysis
▪ Visit workplace understand processes
▪ Review hygiene data where available (may require further
workplace monitoring)

24.  Epidemiological investigation
Sir Bradford Hill established the following nine criteria for causation (does
factor A cause disorder B).
▪ Strength of the association. How large is the effect?
▪ The consistency of the association. Has the same association been
observed by others, in different populations, using a different method?
▪ Specificity. Does altering only the cause alter the effect?
▪ Temporal relationship. Does the cause precede the effect?
▪ Biological gradient. Is there a dose response?
▪ Biological plausibility. Does it make sense?
▪ Coherence. Does the evidence fit with what is known regarding the natural
history and biology of the outcome?
▪ Experimental evidence. Are there any clinical studies supporting the
association?
▪ Reasoning by analogy. Is the observed association supported by similar
associations?

25.  Treatment
 Treat emergent medical issues
 Decide on return to work strategies
▪ Fit to work
▪ Job modification (workplace, procedures)
▪ Modified working hours
▪ Modified duties (fit to work with restrictions)
▪ Redeployment
▪ Ill health retirement

28.  Five (5) steps
1. Hazard Identification
2. Risk assessment
3. Control measures
(Hierarchy of control)
4. Monitoring
5. Audit

29.  Hazard
Potential adverse effect of an agent or
circumstance
E.g. Mesothelioma is a hazard of asbestos
 Risk
Probability that a hazard will be realized, given
the nature and extent of a person’s exposure to
an agent or circumstance
E.g. Risk of mesothelioma from asbestos
depends on the type of fibre and the amount
that is inhaled

30. How do the Occupational Physicians identify
hazards?
 Clinical Assessment
 Toxicological Assessment
 Epidemiological Assessment

31.  Exposure Assessment
 Determine what are the nature and extent of the
exposures that will occur if a course of action is
followed.
 Estimation of risk
 Determine what is the likely probability of each
hazard if the course of action is followed

32. • ELIMINATION
• SUBSTITUTION
• Procedure, agent
• ENGINEERING CONTROLS
• Ventilation, enclosures
• ADMINISTRATIVE CONTROLS
• Information, instruction, training; task rotation ; health surveillance
• PPE
• Hard hat, ear plugs, glasses, gloves, coveralls, boots

33.  Monitoring compliance with controls
 Company enforcement
 Regulatory bodies (OSH Agency)
 Audit controls
 Set standard
 Measure performance
 Review
 Implement change
 Repeat cycle

34. CASE 1
Lead Poisoning In A ConstructionWorker

35. Clinical Investigation
 History
 Medical
25 year old male
4 week history – lethargy, abd pain, headaches, Nausea
Recent onset – weakness and tingling sensation - Hands
Smoker
 Occupational
General labourer with contracting firm for 2 years
Repair and refurbish old building
Use of sander to remove paint from walls

36.  Physical Examination
 Generalized abdominal tenderness
 Other wise unremarkable
 Investigations
 Blood
Elevated blood lead levels
Blood film – basophilic stippling of erythrocytes
Consistent with lead poisoning

37. Workplace Investigation
 Several employees performing similar duties
 Not provided with adequate or sufficient PPE
 Coveralls, boots, dust masks
 No provision for respirators
 Share safety glasses
 No dedicated site for breaks
 Took breaks and ate meals in the building they
were repairing

38. Diagnosis &Treatment
 Acute lead poisoning
 Suspended from work based on recorded
blood lead level (Used exposure limits set by
Control of Lead atWork Regulations UK)
 Referred to Internal Medicine for Chelation
therapy.

39. Occupational HealthCase Management
 Employee
 Surveillance
▪ Biological monitoring (blood lead levels) monthly until
acceptable level
▪ Condition significantly improved one month later
however still unfit to work
▪ Job modification not an option
▪ Redeployment not an option
▪ Ill health retirement not considered (temporary issue)
(No attempts by employer to improve work practices)

40.  Employer
 Duty to assess the risks to his workers as
stipulated in the Occupational Safety and Health
Act ofTrinidad &Tobago
 Complete the required risk assessment
 Institute measures considered to be reasonably
practicable to prevent or control exposures
without resorting to the use of PPE as the initial
control

41.  Employer
 Elimination and substitution not viable options
 Engineering controls
▪ Introduction of local exhaust ventilation (vacuum sys)
▪ Dust suppression techniques (use of water)
 Administrative controls
▪ Provision of clean eating and rest facilities as well as suitable washing facilities
▪ Enforcement of separate clean and dirty zones, banning smoking, drinking and
eating in the latter
▪ Information, instruction and training with respect to lead
▪ Implementation of pre employment screening as well as a health surveillance
program for all at risk employees inclusive of biological monitoring
▪ Respiratory fit testing for employees using Respiratory PPE
 PPE
▪ Provision of adequate and sufficient PPE

42. Summary
 Employee no longer works for the general contracting
firm having opted instead to seek employment
elsewhere
 Issues
 Employer did not consider all elements of the hierarchy of
control
 Jumped straight to PPE and even that may have been
inappropriate (Respiratory PPE)
 No national policy or guideline addressing lead exposure
at work as well as exposure limits to be enforced
 Which international best practice regarding exposures and
limits should we follow (UKVS USA)

43. CASE 2
Organophosphate Poisoning In A Pesticide
Sprayer

45. Dr.Wayne Ramgoolam
MB.BS, MSc Occupational Medicine (UK), MFOM
Occupational Medicine Specialist
Phone: (868)-385-6000
Email: wayner@occumedltd.com
www.occumedltd.com