Investigation of Occupational and Environmental Diseases

1. Investigation of Occupational and Environmental Diseases Dr. Somkiat Siriruttanapruk Bureau of Occupational and Environmental Diseases Department of Disease Control

2. “Welcome to the world of occupational disease and injury- a highly challenging and difficult area requiring not only great operational and technical skills but in many ways, a different mindset for the field epidemiologist.” William E. Halperin

3. WorkHealth

4. Occupational Diseases “…are diseases arising out of, or in the course of, work or employment – resulting from the exposure of health hazards at work.”

5. Work-Related Diseases “… are categorized as multifactorial in origin. These are diseases in which workplace factors may be associated in their occurrence but need not bea risk factor in each case.”

6. Occupational diseases Occurs mainly among working population Cause-specific Exposure at workplace is essential Notifiable and compensable Work-related diseases Occurs largely in the community Multifactorial in origin Exposure at workplace may be a factor May be notifiable and compensable Differences between Occupational and Work-Related Diseases

7. Occupational health hazards • Physical factors • Chemical factors • Biological factors • Ergonomic factors and other unsafe conditions • Psycho-social aspects of work

10. The objectives of occupational disease investigation1. To confirm the diagnosis of occupational diseases in patients2. To identify causative or other risk factorsrelated to work for further prevention and control of occupational diseases in both patients and other workers

11. Types of investigation1.Clinical Investigation2.Investigation of the Workplace3. Epidemiological Investigation

12. Clinical Investigation

13. Aims • To establish the pathological and functional diagnosis • To identify the cause of the disease

14. Components of the investigation1. History taking2. Physical examination3. Laboratory tests

15. Components of an occupational history • Job description/nature of job • Duration of work • Types of hazards • Past occupations • Other jobs including hobbies • Preventive measures provided in workplace • Results of health check-up and workplace measurements • Past history of occupational illnesses • Domestic exposures

16. Other relevant informationfor confirmation of the diagnosis • Similar complaints among other workers(Clustering of illness) • Time relationship between work and symptoms (Time sequence) • Degree of exposure • Relationship of illness to periods away from work • Personal history (Smoking/alcohol intake/drugs)

17. Problems in history taking • End occupations • Job titles • Multiple jobs

18. Important points for consideration in clinical investigation • Contact and communication with responsible physicians • Confidentiality of patient’s information • Collection of the informationas much as you can • Co-operation with other relevant agencies

19. Investigation of the workplace

20. Aims • To identifya cause of the patient’s illness • To find out whether other workers are affected • To find out whether the cause can be eliminated

21. Obstacles for conducting workplace investigation • Ethical problems • Unfamiliarity with the approach to management • Industrial relationship problems • Lack of time • Ignorance of how to go about it

22. Steps of workplace investigation • Before entering the workplace • The visit • After the visit

23. Preparations before entering the workplace • Setting up the objectives • Setting up the team • Preparation of tools and equipment • Preparation of information and knowledge • Making contact with workplace • Ethical consideration

24. How to make contact with the workplace • Seeking the advice of expert in the field • Contacting relevant agencies • The approach to management 1.1 Directly to company’s doctor 1.2 Factory manager 1.3 Workers’ representatives or trade unionists • Reasons for requesting a visit

25. Activities of the visit • Meeting with managers or other representatives • Asking for initial information • Walk-through survey • Analysis of initial situation • Initial report or communication • Recommendations and making further appointment

26. Walk-through survey “ …is the most important and easiest activity in occupational health practice for which all occupational health personnel have to do in order to know and to get information about what and how workers perform their work.”

27. The information needed from the walk-through survey • General information of the enterprise • Work process • Health hazards • Other high risk factors • Clues for appropriate preventive and control measures

28. Other important information needed • Material Safety Data Sheet • Information of the provision of occupational health service: 1. Data on environmental measurements 2. Data on health surveillance of workers • Information of workers with occupational diseases and injuries • Information of chemical incidents and other accidents

29. Material Safety Data Sheets (MSDS) “…are produced by the chemical manufacturers in a wide variety of formats and data quality, and aimed primarily at employers of people handling chemicals.”

30. MSDS’s online • http://msds.pdc.cornell.edu/ • http://hazard.com/msds/index.php • http://www.ilpi.com/msds/index.html

31. Practical points for walk-through survey • The survey should start from the entry of raw materials, follows by an order of each step until the finishing of the final product including maintenance section. • The survey should be made in the company of someone who understands the workplace and the process. • Observing what workers actually do their work, including how to protect themselves from health hazards. • Paying attention to the particular job in question, especially the conditions that may cause the illness of patient.

32. The Check-list …is an useful tool to collect the information during the survey. It also assists to achieve the objectives of the survey.

33. Components of the check-list • General informationof enterprise • Basic information of workers • The provision of occupational health service • Work process and diagram • Health hazards and their risk • Recommendations for preventive and control measures • Making next appointment for further assessment • Signature of surveyor and date of the survey

34. Methods for collecting data and information • Observation • Asking and interviewing 1. Representative who were accompanied with during the survey 2. Occupational health personnel in enterprise 3. Workers • Direct measurement

35. Activities after the visit • Searching for more information and knowledge • Consulting the experts • Preparation for furthermeasurements and investigation • Data analysis • Preparation of report • Communication with the workplace and other relevant organizations

36. Epidemiological investigation

37. Aims • To identify the magnitude of the problem • To describe the outbreak in terms of time, place, persons • To identify or confirm the cause of the disease • To identify other high risk factors

38. Steps of investigation • Confirm the outbreak • Verify the diagnosis • Define the case and identify magnitude of the problem • Describe the outbreak in terms of time, place, and person • Identify high risk group • Set up the hypothesis and design the study • Conduct the study • Collect and analyze the data • Summarize and write the report • Implement preventive and control measures

39. Kinds of studies or investigation • Investigation of cases of known occupational etiology • Investigation of cases of unknown etiology • Determination of whether exposure is associated with an adverse health outcome • Evaluation of the effectiveness of an intervention

40. Issues of concern for investigations • The request for assistance • The right of entry • Trade secrets and workers’ confidentiality • Participation of company, union, government agencies, and media • Notification of results • Preparation for the consequences of the investigation

41. Other considerations in conducting occupational investigations • An epidemic in workplace may or may not be of occupational etiology. • Consider overall adverse health outcome rather than one specific disease • Beware of “Healthy worker effect”

42. Conclusions • The investigations of occupational and environmental diseases share a reliance on basic methods of epidemiology. • The investigators need well co-operation or support of other experts in this field. • The social and economic complexities and other related issues need to be concerned or aware of. • The prevention and control of diseases is the ultimate goal of the investigation.

43. Recommendations for new investigators • Try to keep on practicing the investigation to gain more experience • Work together with the others as a teamwork • Join a network with experts in this field • Study hard • Disseminate your study to public