NATIONAL OCCUPATIONALSAFETY AND HEALTH WEEK 2013

Overview of Occupational disease

Case Studies

Dr Wayne Ramgoolam

Head Occupational Health Unit South West Regional Health

Authority

ILO Facts and figures

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

SUMMARY

Overview of Occupational Disease Definition Historical perspective Classification Management Prevention

Case Studies

Definitions of occupational diseases

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 occupationsILO 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 disease2. 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.

HISTORICAL PERSPECTIVE ON OCCUPATIONAL DISEASE

BIRTH OF OCCUPATIONAL MEDICINE

Bernardino Ramazzini (1633 – 1714)

Considered to be the father of occupational and industrial medicine

Diseases of Workers(De Morbis Artificum Diatriba) First edition - 1700 Second edition - 1713

Bernardino Ramazzini (1633 – 1714)

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?"

Sir Percivall Pott (1714 – 1788)

Chimney Sweepers’ Cancer of the scrotum

first to associate cancer with occupational exposure (1775)

Sir Percivall Pott (1714 – 1788) 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

Alice Hamilton (1869 – 1970)

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”).

Radium Girls

Radium Girls

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

HISTORY

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 International Congress on workers’ diseases in Milan - 1906 - ICOH

CLASSIC OCCUPATIONAL DISEASES

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

CLASSIFICATION OF OCCUPATIONAL DISEASES

List of occupational diseases (ILO)

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

OCCUPATIONAL HAZARDS Physical Chemical Biological Mechanical &

Ergonomic Psychosocial

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 & handlingPoor postureRepetitionPoor equipment & workplace design

Psychosocial Organizational Psychosocial FactorsHigh demandLow control

Violence and aggressionLone workingShift workNight workLong working hours

OCCUPATIONAL DISEASES

Target organ systems Occupational infections Respiratory & Cardiovascular disorders Skin disorders Musculoskeletal disorders GI & Urinary Tract disorders Eye disorders Neurological disorders Psychiatric disorders Reproductive disorders Haematological disorders Medically unexplained occupational disorders

OCCUPATIONAL DISEASES

Occupational Infections Respiratory & Cardiovascular

Blood borne virusesHep B,CHIV

Meningococcal TuberculosisLegionnaires TetanusInfluenzaZoonoses

Anthrax (cows,sheep)Glanders (horses, cats, dogs)Brucellosis (cows, sheep, goats, pigs)Lyme disease (deer)Q fever (sheep, cows goats)Orf (sheef)

Occupational AsthmaCOPDHypersensitivity pneumonitis

Farmer’s lung (mouldy hay, grain, straw)Bird fanciers lung (bird excreta)Mushroom workers lung (mushroom compost)Bagassosis (bagasse from sugar caneMalt workers lung (mouldy barley)Ventilation pneumonitis (water in AC systems)

Metal fume feverPneumoconioses

Coal workersAsbestosis Silicosis

Lung cancerPleural disorders (mesothelioma)Coronary heart disease

OCCUPATIONAL DISEASES

Skin Musculoskeletal

GI & Urinary

Eye Neurological

DermatitisContact urticariaSkin cancerPigmentation disordersPhotodermatitisscleroderma

Lower back painWRULD’SCarpal tunnelTenosynovitiscapsulitis

Hepatic AngiosarcomaCirrhosisHepatotoxicityGI cancersRenal failureBladder cancer

ConjunctivitisCataractRetinal burns

Brain cancerParkinsonismOrganophosphate HAVSNIHL

Psychiatric

Reproductive Haematological Unexplained

PsychosesStressPTSD

Impaired fertilityAdverse pregnancy

Bone Marrow aplasiaMethaemoglobinaemiaHaemolysisHaematological malignancies

Sick building syndrome

MANAGEMENT OF OCCUPATIONAL DISEASE

MANAGEMENT

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)

MANAGEMENT

Epidemiological investigationSir 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?

MANAGEMENT

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

PREVENTION OF OCCUPTIONAL DISEASE

PREVENTION

Five (5) steps1. Hazard

Identification2. Risk assessment3. Control measures

(Hierarchy of control)

4. Monitoring5. Audit

DEFINITIONS

HazardPotential adverse effect of an agent or circumstanceE.g. Mesothelioma is a hazard of asbestos

RiskProbability that a hazard will be realized, given the nature and extent of a person’s exposure to an agent or circumstanceE.g. Risk of mesothelioma from asbestos depends on the type of fibre and the amount that is inhaled

HAZARD IDENTIFICATION

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

RISK ASSESSMENT

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

Hierarchy of control

•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

PREVENTION

Monitoring compliance with controls Company enforcement Regulatory bodies (OSH Agency)

Audit controls Set standard Measure performance Review Implement change Repeat cycle

CASE STUDIES

CASE 1Lead Poisoning In A Construction Worker

CASE STUDY Lead Poisoning In A Construction Worker

Clinical Investigation History

Medical25 year old male4 week history – lethargy, abd pain, headaches, NauseaRecent onset – weakness and tingling sensation - HandsSmoker

OccupationalGeneral labourer with contracting firm for 2 yearsRepair and refurbish old buildingUse of sander to remove paint from walls

CASE STUDY Lead Poisoning In A Construction Worker

Physical Examination Generalized abdominal tenderness Other wise unremarkable

Investigations Blood

Elevated blood lead levelsBlood film – basophilic stippling of

erythrocytesConsistent with lead poisoning

CASE STUDY Lead Poisoning In A Construction Worker

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

CASE STUDY Lead Poisoning In A Construction Worker

Diagnosis & Treatment Acute lead poisoning Suspended from work based on

recorded blood lead level (Used exposure limits set by Control of Lead at Work Regulations UK)

Referred to Internal Medicine for Chelation therapy.

CASE STUDY Lead Poisoning In A Construction Worker

Occupational Health Case 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)

CASE STUDY Lead Poisoning In A Construction Worker

Employer Duty to assess the risks to his workers as

stipulated in the Occupational Safety and Health Act of Trinidad & 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

CASE STUDY Lead Poisoning In A Construction Worker 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

CASE STUDY Lead Poisoning In A Construction WorkerSummary 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 (UK VS USA)

CASE STUDIES

CASE 2Organophosphate Poisoning In A Pesticide Sprayer

QUESTIONS

THANK YOU

Dr. Wayne RamgoolamMB.BS, MSc Occupational Medicine

(UK), MFOMOccupational Medicine SpecialistPhone: (868)-385-6000Email: wayner@occumedltd.com www.occumedltd.com