Overview of occupational disease dr wayne ramlogan
Overview of Occupational diseaseCase StudiesDrWayne RamgoolamHeadOccupational Health UnitSouthWest Regional Health Authority
Worldwide, occupational diseases continue to be the leadingcause 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 ordisease. Every 15 seconds, 151 workers have a work-related accident
Overview of Occupational Disease Definition Historical perspective Classification Management Prevention Case Studies
Any disease contracted as a result of an exposure to risk factors arising fromwork 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 dangerousconditions in processes, trades or occupationsILO Employment Injury Benefits Recommendation, 1964 (No. 121), Paragraph6(1) Two main elements are present in the definition of an occupational disease:1. the causal relationship between exposure in a specific working environment orwork activity and a specific disease2. the fact that the disease occurs among a group of exposed persons with afrequency above the average morbidity of the rest of the population.
Considered to be thefather of occupationaland industrial medicine Diseases ofWorkers(De Morbis ArtificumDiatriba)First edition - 1700Second edition - 1713
published the first systematic study connecting theenvironmental hazards of specific professions to diseaseExample: lead exposure in potters and painters His book on occupational diseases outlined the healthhazards and other disease-causative agentsencountered by workers in 52 occupations. This was one of the founding and seminal works ofoccupational medicine and played a substantial role inits development. It was he who proposed that physicians should extendthe list of questions that Hippocrates recommendedthey ask their patients by adding, "What is your trade?"
Chimney Sweepers’Cancer of the scrotum first to associate cancerwith occupationalexposure (1775)
In what represents one of the earliestepidemiologic studies (or studies of theoccurrence and causes of disease), Pott observedthat chimney sweeps in England had higherrates of scrotal cancer than the rest of thepopulation. In doing their jobs, the chimney sweeps oftenhad to climb into chimneys and sufferedprolonged exposure to soot containingpolycyclic aromatic hydrocarbons
founder of occupationalmedicine in the U.S. andthe first woman on thefaculty of HarvardMedical School took a leading role in twomajor environmentalcontroversies of the1920s involving leadedgasoline and radium dialpainters (known as the“radium girls”).
The Radium Girls were female factory workers whocontracted radiation poisoning from painting watch dialswith glow-in-the-dark paint at the United States Radiumfactory in Orange, New Jersey around 1917. The women, who had been told the paint was harmless,ingested deadly amounts of radium by licking theirpaintbrushes to sharpen them; some also painted theirfingernails and teeth with the glowing substance. Five of the women challenged their employer in a casethat established the right of individual workers whocontract occupational diseases to sue their employers The litigation and media sensation surrounding the caseestablished legal precedents and triggered the enactmentof regulations governing labour safety standards
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 – periodicexams▪ Notification of industrial disease – lead, phosphorus, arsenic, anthrax Common law – employer liable if negligent WC legislation in Europe20th Century WC legislation in North America Development of government agencies and professional associations InternationalCongress on workers’ diseases in Milan - 1906 - ICOH
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
Occupational diseases caused by exposure to agentsarising from work activities (Hazards) Diseases caused by chemical agentsDiseases caused by physical agentsDiseases caused by biological agents Occupational diseases by target organ systems Occupational respiratory diseasesOccupational skin diseasesOccupational musculo-skeletal disordersMental and behavioural disorders Occupational cancer Cancer caused by the following agents Other diseases
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 furtherworkplace monitoring)
Epidemiological investigationSir Bradford Hill established the following nine criteria for causation (doesfactor A cause disorder B).▪ Strength of the association. How large is the effect?▪ The consistency of the association. Has the same association beenobserved 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 naturalhistory and biology of the outcome?▪ Experimental evidence. Are there any clinical studies supporting theassociation?▪ Reasoning by analogy. Is the observed association supported by similarassociations?
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
Five (5) steps1. Hazard Identification2. Risk assessment3. Control measures(Hierarchy of control)4. Monitoring5. Audit
HazardPotential adverse effect of an agent orcircumstanceE.g. Mesothelioma is a hazard of asbestos RiskProbability that a hazard will be realized, giventhe nature and extent of a person’s exposure toan agent or circumstanceE.g. Risk of mesothelioma from asbestosdepends on the type of fibre and the amountthat is inhaled
How do the Occupational Physicians identifyhazards? Clinical Assessment Toxicological Assessment Epidemiological Assessment
Exposure Assessment Determine what are the nature and extent of theexposures that will occur if a course of action isfollowed. Estimation of risk Determine what is the likely probability of eachhazard if the course of action is followed
• 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
Monitoring compliance with controls Company enforcement Regulatory bodies (OSH Agency) Audit controls Set standard Measure performance Review Implement change Repeat cycle
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
Physical Examination Generalized abdominal tenderness Other wise unremarkable Investigations BloodElevated blood lead levelsBlood film – basophilic stippling of erythrocytesConsistent with lead poisoning
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 theywere repairing
Diagnosis &Treatment Acute lead poisoning Suspended from work based on recordedblood lead level (Used exposure limits set byControl of Lead atWork Regulations UK) Referred to Internal Medicine for Chelationtherapy.
Occupational HealthCase Management Employee Surveillance▪ Biological monitoring (blood lead levels) monthly untilacceptable level▪ Condition significantly improved one month laterhowever 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)
Employer Duty to assess the risks to his workers asstipulated in the Occupational Safety and HealthAct ofTrinidad &Tobago Complete the required risk assessment Institute measures considered to be reasonablypracticable to prevent or control exposureswithout resorting to the use of PPE as the initialcontrol
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 andeating in the latter▪ Information, instruction and training with respect to lead▪ Implementation of pre employment screening as well as a health surveillanceprogram for all at risk employees inclusive of biological monitoring▪ Respiratory fit testing for employees using Respiratory PPE PPE▪ Provision of adequate and sufficient PPE
Summary Employee no longer works for the general contractingfirm having opted instead to seek employmentelsewhere Issues Employer did not consider all elements of the hierarchy ofcontrol Jumped straight to PPE and even that may have beeninappropriate (Respiratory PPE) No national policy or guideline addressing lead exposureat work as well as exposure limits to be enforced Which international best practice regarding exposures andlimits should we follow (UKVS USA)
CASE 2Organophosphate Poisoning In A PesticideSprayer
Dr.Wayne RamgoolamMB.BS, MSc Occupational Medicine (UK), MFOMOccupational Medicine SpecialistPhone: (868)-385-6000Email: firstname.lastname@example.org