Basic Concepts in Occupational Medicine

1. Basic Concepts in Occupational Medicine Occupational Health Unit Royal Free Hospital

2. Aims & Objectives Aim: To be able to apply the basic principles of occupational medicine to your professional practice as doctors Objectives: 1. Know what questions to ask in order to take an appropriate and relevant occupational history 2. Identify factors or patterns in a patient’s history that may indicate a work related contribution to ill health 3. Consider a work related health dilemma and reach a conclusion with reasons 4. List 3 causative agents and related work activities for occupational asthma, allergic contact dermatitis and cancer. 5. Specify what information is necessary to make a fully informed assessment of an individual’s medical fitness for work

3. Occupational Health • Work Health (occupational disease/work related ill health) • Health Work (medical fitness for work)

4. Occupational Medicine/Health a branch of medicine concerned with the interaction between health and work (“occupation”) Occupational Therapy assessment & treatment to enable maximum independent function in daily living, using purposefulactivity (“occupation”) Occupational Health/Therapy

5. Case 1: The Hazards of Work You are an occupational physician. A 31-year-old laboratory technician is referred to your clinic by her manager, because of alleged lateness and poor performance at work. You are asked to assess whether there is an underlying medical cause for this. She tells you that she has not been sleeping well lately, possibly due to nocturnal coughing. She says the lab is cold and drafty, and that by the end of the working day her right arm is aching. She says that when she told her manager, he was unsympathetic; telling her she should leave if she doesn’t like the job. 1. What are the presenting medical problems? 2. What are the possible work-related causes of her symptoms? 3. What are the potential hazards in her workplace and how might you classify them? 4. How will you respond to the manager’s questions?

6. Classification of work hazards • Physical • Mechanical • Chemical • Biological • Psychosocial

7. Hazard and Risk • Hazard: potentially harmful • Risk: probability of harm (quantifiable as risk assessment)

8. Principles of Control of Workplace Hazards • Identify • Evaluate • Control • Eliminate • Substitute • Enclose/separate • PPE/vaccinate

9. Case 2: Is it work-related? A 58-year-old hospital porter has been off sick for almost a year, with low back pain. He says he injured his back at work. His back pain has not improved with physiotherapy and analgesia. He has difficulty walking up and down stairs and is breathless on exertion. His occupational history is as follows: ·Left school at 15 ·Had numerous labouring jobs in the construction industry for 20 years or so ·Worked on a tunnelling project for 18 months ·Worked as a lorry driver for a brewery for 8 years ·Worked as a hospital domestic assistant for 2 years ·Has been employed as a hospital porter for 11 years 1.What occupational hazards might account for his breathlessness? 2. How would you assess whether his symptoms are work related or not? 3. What are the possible causes of his back pain? 4. What advice would you give him? 5. Is he likely to be return to work? 6. What work might he be able to do?

10. Presentation of Occupational Disease • Pathology • Timing of symptoms • Possible causes • Elicit relevant history

11. The Occupational History • What is your job? What do you do for a living? • What do you do at work? What do you work with? What is a typical working day? • How long? What else? • Any known hazards? Anyone else with similar symptoms? • Hobbies? (DIY, pets, gardening, chemicals)

12. Occupational Asthma Occupational Asthma • Asthma induced by specific substances encountered in the work place. It may occur in individuals who would otherwise not have developed asthma Work-related Asthma • Asthma which relates to substances in the work place (resp irritants) that exacerbate asthma in people with pre-existing asthma

13. Isocynates Platinum salts Proteolytic enzymes Wood dusts Glutaraldehyde Soya bean Persulphates or henna Crustaceans or fish products Grain / Flour (barley, oats, wheat, maize) Caster bean dust Laboratory animals Antibiotics Latex Soldering flux (colophony) Ispaghula Tea dust Causes of Occupational Asthma

14. risk exposure Dose response relationship KOH 2006

15. UK detergent factory: incidence of occupational asthma vs enzyme use

16. UK detergent factory: incidence of occupational asthma vs enzyme use

17. UK detergent factory: incidence and new employees

18. UK detergent factory: incidence among new employees vs enzyme use

19. Investigation of a case of suspected Occupational Asthma History • Symptoms • Associated symptoms • Duration • Work history • Is patient aware of exposure to any respiratory sensitisers at work? • Timing of symptoms (immediate /delayed) • Improvement away from work • Adult onset • Smoking history • History of atopy

20. Investigation of a case of suspected Occupational Asthma Clinical investigations • 2hrly PEFR • Skin prick test • RAST / ELISA • Spirometry • Bronchial challenge

22. Management • Drug treatment • as for non-occupational asthma • Non-drug treatment • Remove from exposure • Review work place • Is prevention possible? • Are control measures adequate? • Compliance with (COSHH) regulations? • Health surveillance

23. X X X surveillance no surveillance UK Supermarket bakeries What happens when a supermarket opens? No cases of occupational asthma Increased incidence of occupational asthma

24. Occupational Dermatitis • Endogenous (constitutional) • Exogenous (contact) • Irritant (acute/chronic) • Allergic (immediate/delayed)

25. Allergic Latency Lag period Eye lid swelling Papules and vesicles Exposure to a known sensitiser Irritant usually involves the hands Scaling and redness Papules and vesicles are unusual Exposure to a known irritant Occupational Dermatitis

26. Irritant “Wet work” Soap detergents vegetable juices/fruit fish/meat dough Allergic Latex Biocides/preservatives (e.g. formaldehyde) Chrome salts Plant allergens (e.g. onion, garlic, spices) Epoxy resin monomers Hairdressing chemicals Causes of Occupational Dermatitis

27. History • Duration • Site • Work history • Exposure to known allergens/irritants • Improvement away from work • Treatment

28. Management • Avoid exposure • Allergen/irritant replacement • Skin protection • Change job • Drug treatment

29. Target Organ Lung Nasal sinuses Urothelial tract Liver(angiosarcoma) Carcinogen Asbestos, As, Be, Cd, Cr(VI), Ni, Fe, BCME Ni Rubber, Dyes, Al, Tar/pitch VCM Occupational Cancer

30. Industrial Injuries Disablement Benefit • Prescribed diseases (IIAC) • relevant disease • relevant occupation • Administered by DWP

31. Case 3: Assessing fitness for work Y You are an occupational physician. A 29-year old HIV positive doctor has been offered a post on an anaesthesia rotation. 1.Is it relevant to know how HIV was acquired? 2.How will you assess whether s/he is medically fit for the job? 3.What information will you need, to make a fully informed assessment?

32. Fitness for work • Job • Relevant medical history • Risks (self, colleagues, employer, public)

33. A Model Framework for Assessment of Medical Fitness for Work

34. Aims & Objectives Aim: To be able to apply the basic principles of occupational medicine to your professional practice as doctors Objectives: 1. Know what questions to ask in order to take an appropriate and relevant occupational history 2. Identify factors or patterns in a patient’s history that may indicate a work related contribution to ill health 3. Consider a work related health dilemma and reach a conclusion with reasons 4. List 3 causative agents and related work activities for occupational asthma, allergic contact dermatitis and cancer. 5. Specify what information is necessary to make a fully informed assessment of an individual’s medical fitness for work