LECTURE SLIDES ON OCCUPATIONAL HEALTH.ppt
- 1. OCCUPATIONAL HEALTH Jonathan C. Daboer, MBBS,MSc, FMCPH Department of Community Medicine, College of Health Sciences, University of Jos
- 2. LEARNING OBJECTIVES • At the end of this course, the student should be able to – define and understand the objectives of OH – relate the work environment with possible work related injuries, diseases & illnesses – Discuss principles of hazard control & Disease prevention in OH – Discuss some occupational diseases and relate them to the associated occupations – Discuss some legislations relevant to OH
- 3. Introduction • Occupational Medicine/Health • Industrial Hygiene/Occupational Safety Why bother about people’s job? • Effect of health on work – Positive effect of good health – Negative effect of Poor health • Effect of work on health – Positive – negative
- 4. Work and health: the links Positive effect of good health on work Increased productivity, wealth creation and community prosperity Give ability to be creative at work, leading to job satisfaction thereby reinforcing health Negative effect of poor health on work Poor productivity, decline in income, individual and communal poverty Increased accidents, industrial loses Infectious disease transmission to other workers
- 5. Work and health: the links Positive effect of work on health Generates income to take care of needs (food, health, social roles) leading to improved health and wellbeing Opportunity to be creative Relieves boredom Improves self-esteem Negative effects of work on health This is the pre-occupation of OH Results from components of the work environment Biological: TB, Lassa fever, hepatitis B & C, COVID-19, schistosomiasis Chemical: poisoning from pesticides, fertilizers, grain preservatives Mechanical: RTAs (drivers), auto amputation from grinding machines Physical: fire outbreaks, heat syndromes, lung disease(dusts &
- 6. Definition (WHO/ILO1950) • Sum total of all the activities and programs that are engaged upon aiming to attain and maintain the highest level of health and safety for all people who are engaged in any type of work whatever
- 7. Objectives – Promotion and maintenance of the highest degree of physical, mental and social well-being of all workers in all occupations – Prevention, among workers, of departures from health caused by their working conditions – Protection of workers in their employment from risks resulting from factors adverse to health
- 8. – Planning and maintenance of workers in an occupational environment adapted to their physiological equipment; and to summarise: – Adaptation of work to man and each man to his job
- 9. History • Hippocrates (460-370 BC)—On Airs, Waters and Places— occupation and environment relevant to health • Georgius Agricola (1494-1555):treatise on mining and metal industries (De Re metalica) • Miners short of breath, die prematurely • In his treatise he told the story of a woman who married and outlived seven different men who were miners of gold and silver (Czech border)
- 10. • Pliny the Elder (Gaius Plinus Secundus 23- AD79)- recognised the dangers in sulfur and zinc in mining and went further to design a face mask for protection • Galen (130-205 AD)- described the dangers of acid mist in copper mines • Phillipus Aureolus Paracelsus (1493-1543) – warned about toxicity due to mercury and sulphur • Wrote ”On the miner’s Sickness and other Diseases of Miners”
- 11. • Bernadino Ramazzini (1633-1714) – Father of occupational medicine. –Systematically studied the role of occupations and work places in disease causation –At 67 wrote his book “De Morbis Artificum diatriba” (Diseases of Tradesmen, 1713)
- 12. • −“When a doctor visits a working-class home, he should be content to sit on a three-legged stool if there isn’t a gilded chair, and he should take time for his examination; and to the questions recommended by Hippocrates (Affectations), he should add one more— ‘What is your occupation?’”
- 13. • Percival Pott- Chimney sweeps and scrotal Carcinoma • George Baker – abdominal colic and lead poisoning • Charles Turner Thackrah –1st British treatise on occupational health “Diseases of the arts, trades and professions and of certain civic states and ways of living” in 1832 –This led to the passage of the first ever British factories act of 1833
- 14. • Thomas Legge (1863-1932) –Appointed 1st medical inspector of factories in Britain in 1898 –Developed 4 important aphorisms: –“Unless and until an employer has done everything - and every thing means a good deal - the workman can do next to nothing to protect himself, although he is naturally willing enough to do his share”.
- 15. – “if you can bring an influence to bear external to the workman – that is one over which he has no control – you will be successful; and if you cannot or do not, you will never be wholly successful”. – “Practically all industrial lead poisoning is due to the inhalation of dust and fume, and if you stop the inhalation you stop the poisoning”. – “All workmen should be told something of the danger of the material with which they come into contact, and not be left to find it out for themselves – sometimes at the cost of their lives”.
- 16. Women’s contribution • Alice Hamilton – Described lead poisoning in bathtub enamelers; carbon monoxide poisoning in steel workers; heart disease in munitions workers; mercury toxicity in hatters; “dead fingers”in jack hammer users; neurologic disease in viscose rayon workers; cancer after benzene exposure
- 17. Crystal Eastman • Work Accidents and the Law,1906–1907 −First systematic investigation of accidents occurring during one year in Allegheny County, Pennsylvania −526 men killed by work accidents in county - 84% < 40 years old - 58% < 30 years of age
- 18. Development of OH in Nigeria First Occupational Health service in Nigeria was introduced in 1789 by the Medical Examination Board of the Liverpool Infirmary for the purpose of caring for the health of European slave traders from Africa to Britain. With the cessation of slave trade, the Royal Niger Company of Britain increased its trading activities in Nigeria and therefore organized its own health service in 1899 which were later taken over by U.A.C.N
- 19. Rapid industrialization after the world war Railway construction, tin and coal mining Employment of young men, working long hours (12- 14 hours/day, 7 days/week) Working environments were dirty, noisy, dusty, poorly illuminated, poorly ventilated with poorly maintained machines and noxious fumes Living conditions were overcrowded and congested The result was that workers were dying in their forties and fifties
- 20. As a result of the ignorance of the relationship between working conditions and health, the workers accepted the work associated diseases and injuries as part and parcel of the job Employers attributed the employees poor health and early death to the workers personal habits and living conditions at home. As a result little or no attention was paid to the prevention of workplace hazards. Payment was poor and dismissal frequent because many hands were available to hire and no workers’ unions or other pressure groups available
- 21. These dehumanizing conditions led to the coal workers riots in Enugu in 1945-1949 with many of them killed, drawing public attention to their plight. The result was the introduction of OH services in some industries and the enactment of some occupational health legislations in Nigeria. Industries where OH services were established included John Holt, Nigerian Railway Corporation (1930), Coal Mines(1930) Where health services could not be established general practitioners were hired on part time basis.
- 22. Other developments included the creation of an OH unit in the federal Ministry of Health and the Institute of OH in Oyo State Min of Health. These agencies organized training courses for managers, safety officers, medical officers, occupational hygienists and other personnel involved in the protection, promotion and maintenance of the health and welfare of workers in the country.
- 23. 1941- Workman’s Compensation Ordinance introduced, later replaced by Workman’s Compensation Decree in 1987 1942 -Department of Labour created 1945- Labour Code Ordinance enacted, later replaced by Labour Decree (later Act) of 1974 1951- Ministry of Labour created
- 24. • 1952 - P.R.F Britnell appointed the 1st Chief Inspector of Factories • 1955 - The enactment of the Factories Act, amended in 1958, replaced by decree in 1987 • 1962 – 1st National Industrial Safety Conference in Lagos organized by Britnell • 1963 - The Mineral Oil Safety Regulations (Petroleum Drilling and Product Regulation 1969)
- 25. 1964/68- Lectureship in OH created at the University of Lagos with Dr G. O. Sofoluwe appointed to it 1970- Society of OH physicians was formed 1976 – Division of OH (& Environmental Health) created at the Federal Ministry of Health 1988 - The Fire Service Regulations, which applies to Factories, Industries, Mills and Major Workshops 1988 - The Federal Environmental Protection Agency Decree. National Environmental Protection (Effluent Limitations) Regulation, 1990
- 26. 1990 – Labour Laws reviewed and Act replaced by Decree 1990 - The Public Health Act, operated by the Federal Ministry of Health empowers it to inspect health facilities 1990 - The Mineral Act, enforced by the Federal Ministry of Solid Mineral providing guidelines on mining activities 1990 - Oil Pipeline Act, administered by the NNPC (Petroleum Inspectorate ) 1990 – Creation of Workmen’s Compensation Act administered by Employment and Wages Department of Federal Ministry of Labour and Productivity
- 27. 1991 - National Environmental Protection (Abatement in Industries and Facilities Generating Wastes) Regulation, enforced by FEPA now Federal Ministry of Environment 2010 – Employee’s Compensation Act (operated by NSITF) replaced the Workman’s Compensation Act Petroleum Industries Act 2021
- 28. Organizations concerned with OH. • ILO formed in 1919 with HQs in Geneva, Switzerland • Made up of representatives of govts, employers and workers • WHO- a specialized agency of the UN with HQs in Geneva, Switzerland
- 29. Components of the work environment • Physical • Chemical • Biological • Social (man and man) • Mechanical (man and machine)
- 30. Hazard • A material, circumstance or situation that is a potential source of danger to the health of the worker • Left unchecked, a hazard can result in a disease, injury, disability or death (DIDD)
- 31. Hazard contd A HAZARD is anything that has the potential to cause harm to the detriment of the health or safety of a person (injure people and/or damage their health). There is an unlimited number of hazards that can be found in almost any workplace. It could be equipment (e.g. machinery, tools, etc.), dangerous substances (dust, disease-causing micro-organisms, chemicals, pesticides, noise, etc.), poor workplace layouts, poor work organization, methods or practices and attitudes.
- 32. Route of entry • Inhalation • Commonest route of entry of occupational & environmental substances into the body e.g. fumes, dust, vapour, gas, mists, spray • <5microns in diameter reach the alveoli • Skin contact/absorption • Certain solvents e.g. toluene, methanol and certain mechanical hazards • Ingestion • Due to frequent hand to mouth contact through smoking, eating in the work place • Poor personal hygiene • Injection • Health and laboratory workers
- 33. Risk • The chance of a loss or an injury occurring on account of a hazard • It is the likelihood that a person may be harmed or suffers adverse health effects if exposed to a hazard • RISK is the probability that a hazard will actually result in injury or illness, together with an indication of how serious the harm could be, including any long-term consequences. Thus, risk is a function of the probability (likelihood) of an occurrence of a hazardous event and the severity of injury or damage caused by this event. • It could be summed up as; Risk = severity of harm x probability of harm
- 34. Occupational hazards • Physical hazards – Light – excess: eye stress, cataract, poor vision, accidents - lack: eye stress, loss of vision, accidents – Temperature- Heat: heat exhaustion, heat cramps, heat syncope, heat stroke, burns cold: frost bite, chilblain – Noise: distraction, poor concentration, fatigue, hearing loss – Vibration: arthritis, vibration white fingers – Radiation: radiation sickness, burns, cancers – Humidity: sweating, exhaustion
- 35. Chemical hazards –Elements, compounds and mixtures in the work environment, acids, alkalis, solvents, reagents –Lead – anaemia, intestinal colic, nervous and mental disorders –Mercury- nervous and mental disorder, nephrosis –Nickel – nasal cancer –Benzene – leukemia, –Asbestos – asbestosis, mesothelioma, pleural plaques, lung ca
- 36. Biological hazards – Bacteria – clostridium spp among farmers, TB in healthcare workers, bovine TB & anthrax in cattle rearers – Viruses – rabies in veterinarians and dog & cat rearers – Parasites – Hookworm, schistosomiasis in farmers – Fungal – farmers’ lung, athlet’s foot in farmers • Mechanical hazards – Sharp edges of machines – Pointed ends of machines and tools – Moving machines – Poorly designed tools and equipment – Awkward postures while sitting or standing – Disbalance with human configuration – Belong to the field of ergonomics
- 37. Social hazards – Frustration – Lack of job satisfaction – Job insecurity – Poor pay – Harassment and intimidation – Inability to meet expectations at work – Poor human relationships – Emotional tension • These lead to: – Psychological and behavioural changes – Psychosomatic changes
- 38. Professional groups in occupational health • Occupational physicians • Occupational nurses • Occupational hygienists/toxicologist • Ergonomists/safety engineers • Occupational psychologists • Physiotherapists • The number and category engaged depend on the size of the industry and its sophistication
- 39. Principles of hazard prevention and disease control in OH and safety • Complete elimination • Containment • Adjunct measures
- 40. Complete elimination (1) 1.Substitution - e.g. redesigning the machine to use less toxic chemicals such as fiber glass in place of asbestos, - substituting equipment to remove the source of excessive temperature, noise, or pressure etc. - in laboratory research, toluene is now often used as a substitute for benzene. The solvent-properties of the two are similar but toluene is less toxic and is not categorized as a carcinogen although toluene can cause severe neurological harm - MRI and Ultrasound for X-ray imaging etc
- 41. Complete elimination(2) 2. Change of process - e.g. automation for many previously manually operated processes e.g. glassmaking. - Redesigning a workstation to relieve physical stress and remove ergonomic hazards - or dip coating materials rather than spray coating to reduce the inhalational hazard
- 42. Containment (1) – At source- sound muffling in cars, exhaust ventilation in chemistry labs, wet drilling in mines & construction sites – Total enclosures e.g. transformer stations, moving parts of machinery, -Complete containment of toxic liquids or gasses from the beginning of the process using or producing them to detoxification, -safe packing for shipment, or safe disposal of toxic waste products --Complete containment of noise or heat
- 43. Containment (2) – Partial enclosures – many dangerous machine processes in industries, construction sites – Time limited/regulated/monitored exposure e.g. X ray departments, nuclear reactor plants etc. – Segregation of waste – Isolating the hazard is achieved by restricting access to plant and equipment or in the case of substances locking them away under strict controls. When using certain chemicals then a fume cupboard can isolate the hazard from the person, similarly placing noisy equipment in a non-accessible enclosure or room isolates the hazard from the person(s)
- 44. Containment (3) • Engineering Controls -involve redesigning a process to place a barrier between the person and the hazard or remove the hazard from the person, such as machinery guarding, extraction systems or placing the operator at a remote location away from the hazard.
- 45. Containment (4) • Administrative controls include adopting standard operating procedures (SOP) or safe work practices or providing appropriate training, instruction or information to reduce the potential for harm and/or adverse health effects to person(s) • Isolation and permit to work procedures are examples of administrative controls
- 46. Adjunct measures (1) - Personal protective devices/equipment (PPE) – goggles, masks, etc. - General cleanliness or good house keeping, personal hygiene, PEP -Health education • Information processes e.g. posters, talks, seminars, etc. • Health and safety committees, accident prevention & accident investigation committees • Incentive programmes for safety e.g. prizes & bonuses • Disincentives (carrot & stick)
- 47. Adjunct measures (2) Safety monitoring • Environmental e.g. noise, dust, heat, gases etc. • Biological monitoring of the workers e.g. PCV, blood for lead, etc., LFTs, CXRs, urine, stool exam etc. • Personal monitoring of workers for exposure to hazards (dosimeter) • Periodic sickness record evaluation/monitoring
- 48. Monitoring and review • Monitoring follows implementation of control measures • Aim is to monitor the effectiveness of the control measures • Done through inspection, interview of employees or testing of samples • A review is due after two years (statutory) or when it becomes necessary
- 49. Inherent risk & residual risk • Inherent risk, is the level of risk that an activity/hazard category would pose if no controls or other mitigating factors were in place. • Residual risk is the level of risk associated with an activity after proposed/additional controls have been implemented to further eliminate or reduce the risk. • Where proposed/additional controls are required the residual risk should be lower than the inherent risk. • In some cases where the inherent risk may already be “low”, the residual risk will be the same.
- 50. Functions of occupational health • Medical examination –Pre-employment medical examination • General fitness medical exam • Pre placement medical exam. –Periodic (follow up) medical exam. –Post-employment med exam • Provision of primary medical care including First aid • Environmental monitoring and modification • Monitoring, control & management of workplace effluents • maintenance of accurate health records, their periodic evaluation and review
- 51. Functions contd • Health education • Essential services –water supply –toilets –rest rooms –canteens –Recreation • Planning of factory expansion • Rehabilation
- 52. Organization of OHS • Depends on the: –Political –Size of labour force –Wealth of the industry –Social conditions of the generality of the people • Industries are divided into: –Small scale – 50 workers or less –Medium scale – 51-1000 workers –Large scale – more than 1000 workers
- 53. OHS in large industries • Most have well equipped independent hospitals • Carry out preventive and curative services • Also cater for the health needs of the local people • May be quite sophisticated and staffed with physicians, nurses, pharmacists, lab technicians etc • Staff and relations may be treated free • Some serve as primary care providers under the NHIS • Local people are charged for service rendered
- 54. Small and medium scale industries • Options –Use of part-time (private) practitioners –Use of established health services eg govt or mission –Use of a group occupational health service (GOHS)
- 55. Use of private practitioners • By retainership system a private practitioner is engaged to treat workers in his clinic and payment is made monthly on the basis of the number of workers treated • Common in low and middle income countries • The doctor’s clinic should be as close to the industry as possible
- 56. Private practitioners contd • He comes in at regular hours of the day to see the sick, advise mgt and workers and inspect the work facility • He organizes First Aid services for workers • He Keeps and analyses statistics in order to improve the services • Disadvantage – Too much emphasis on curative services to the detriment of prevention – Poor documentation and analysis of cases seen – Emphasis is on the number of workers treated instead of a reduction of sickness absence
- 57. Use of established health services • Suitable for govt civil servants and staff of other establishments without health service of their own • Aim is ensure that workers are in good health, that their working environment is not hazardous to health and sickness absence and labour turnover are minimized
- 58. Established facilities contd • Both preventive and curative services are given • Statistics of cases treated should be used to monitor the effect of work on health • Doctor should have free access to all departments and the management for advice. • Doctor should avoid being used by workers against mgt and vice versa • Strict confidentiality must be maintained by the doctor
- 59. Group occupational health services • Two or more small or medium scale industries cooperate to provide health service for their workers • Individually they are incapable of providing the service because of size or financial constraint • This type of OHS is cheap and effective • Established ab initio as GOHS or one industry establishes it and then others are invited to join • Two types- estate type and area type of GOHS
- 60. Area type of GOHS Base clinic Plant C Plant B Plant A Plant D Plant F Plant E
- 61. • Suitable where the industries concerned are relatively far from each other • Service has an operational base fairly central to each industry being served • At base is the main clinic building, containing the consulting room, lab, records, drugs etc • Staff requirement vary widely depending on the labour force • Emphasis is on efficient service with minimal staff
- 62. Duties of the nurse • From the central premises the nurses go out daily with their kits containing essential materials eg drugs, dressings etc • Each plant has a treatment room with a First Aid box manned by an employee of the plant • She replenishes the First Aid box • Attends to those who need to be seen • Inspects the working environment especially if there has been an accident about which she needs to write a report to the doctor
- 63. Duties of nurse contd • Cases she cannot manage at the plant are referred to the doctor at the centre • Very severe cases are sent to the hospital immediately using a pro forma and the doctor informed as soon as possible • A copy of the referral letter is shown to the doctor and then kept in the patient’s confidential file • A daily attendance register is kept at the plant (diagnosis, treatment, disposal)
- 64. • Unfit workers are referred to the doctor to determine duration of excuse duty • A copy sent to the personnel officer and a duplicate kept in the centre • This is used to compute sickness absence pattern for the worker and for the industry • Number of plants visited by a nurse in a day depends on the size of each plant, number reporting sick, the distance btw the plants and btw the plants and the base
- 65. Doctor’s responsibility • Planning and overall supervision of the service • Sees cases referred to the base daily • Visits each at least once forth nightly • There should be a roster of the dates and days the doctor is expected to visit each plant • On these days he sees referred cases and accompanies the nurse on her routine duties
- 66. • He also inspects any part of the plant where need be especially if there is evidence of adverse conditions like dust, fumes etc • Periodically analyzes accumulated data and submits a report to management • His advice on the modification of certain work processes must be based on evidence
- 67. communication • Telephone comunication should be maintained btw the plants, and between the plants and the base • At least one functional ambulance for transportation of the sick to the base and for referral of patients to the hospital • The ambulance should be stationed at the base
- 68. Estate type of GOHS Base clinic D E A B F C
- 69. • Suitable in industrial estates • Here industries are located within walking distance of each other • They cooperate to establish an OHS at a fairly central location • All staff and facilities for an OH practice are located in the central building • Essential difference btw the two: – In “Area type” service is taken to the workers while in the “Estate type” the workers travel to the service centre
- 70. Occupational diseases • They are generally regarded as diseases arising out of or in the course of employment e.g asbestosis, HBV infection from needle stick injury among health workers • On the other hand “occupationally related diseases” are diseases that do not necessarily arise from employment but are worsened by the employment e.g. low back ache in bank executives • “Non occupational diseases” are those that occur at the same rate in all persons whether or not in an employment e.g malaria in sub-saharan Africa, flu during winter in Europe.
- 71. Classification • 1. Diseases due to physical agents • Heat: Heat hyperpyrexia, dehydration, heat cramps, heat exhaustion, burns, heat syncope, heat stroke • Cold: frost bite, chilblains • Light: Cataract, • Pressure: Caisson’s disease, air embolism • Noise: deafness and non auditory effects • Radiation: cancer, leukemia, aplastic anaemia, pancytopaenia • Mechanical factors; Accidents and injuries • Electricity: burns, electricution
- 72. Classfication contd • 2. Diseases due to chemical agents • A : Gases - CO, NH3, • B: Dusts (pneumoconiosis) – Inorganic dusts I. Coal dust -----anthracosis II. Silica ---------silicosis III. Asbestos-----asbestosis, Ca lung IV. Iron -----siderosis V. Tin ----- stanosis
- 73. - Organic (vegetable) dust I. Cane fibre ---- bagassosis II. Cotton dust --- byssinosis III. Hay or grain dust- --farmers’ lung IV. Fur proteins--- bird fanciers’ disease C: Metals and their compounds diseases from toxicity of lead, mercury, cadmium, manganese, beryllium, arsenic etc D: chemical poisoning from acids, alkalis E: poisoning from solvents like benzene, chloroform etc
- 74. 3. Diseases due to biological agents brucellosis, anthrax, leptospirosis, psittacosis etc 4. Occupational cancers Ca of the skin, lungs, scrotum and bladder 5. Occupational dermatosis dermatitis, eczema 6. Diseases of psychological origin Industrial neurosis, hypertension, peptic ulcer
- 75. Occupational lung diseases • Earliest known diseases of occupations • Caused by inhalation of gases, fumes, vapours and dusts • Divided into diseases caused by: inorganic (mineral) dusts called the pneumoconiosis) and those caused by organic dusts
- 76. 1.Coal workers pneumoconiosis • A fibrotic lung disease • Results from inhalation of dust containing a mixture of coal and silica during the mining of coal through silica bearing rocks • Sources – Mining of coal, gold, tin, – Quarrying of slate, sandstones, granite – Foundries – Sand blasting • Two types – Simple CWP – PMF
- 77. Simple cwp • Pt may have no symptoms for several years • As the dx progresses he becomes breathless • FEV1 slightly decreased • CXR shows reticulation (increased lung markings) • Reversible on stoppage of exposure • Otherwise it progresses to PMF
- 78. Progressive massive fibrosis • May develop from simple cwp or de novo • Clinical features: wt loss, cough, severe breathlessness, fever and cardiac failure • TB is frequently associated with PMF • Not known whether it is the onset of TB on simple CWP that results in PMF or people with PMF are predisposed to TB • Possibly an immunological factor determines who develops SCWP and who develops PMF • PMF is irreversible
- 79. PMF contd • TLC is reduced • Increased airway resistance leads to reduced FEV1/FVC • Reduced gas transfer • Increased residual volume • Diagnosis: – Occupational history – X ray – Lung function tests • Treatment – Scwp- withdrawal – PMF – nil • Prevention – Engineering measures to control dust – Personal protection – Medical examination – Health education
- 80. 2. Asbestosis • Chronic inflammatory medical condition affecting the lung parenchyma • Occurs after 5-10 yrs of exposure • Caused by inhalation of asbestos dust • Sources – Asbestos mining & milling, – exposure during manufacturing and construction – Maintenance and repair of asbestos containing material I. Thermal insulation II. Acoustic damping III. Roofing sheets, pipes, motor gaskets, floor, cement, tiles etc
- 81. • Pathology –Interstitial fibrosis –Pleural thickening –Pleural plaques with or without calcification –Asbestos bodies –Ca lung –Mesothelioma of the pleura and peritoneum
- 82. Clinical features • Often precede radiological changes • Progressive breathlessness • Cough initially dry but later mucoid or muco purulent when bronchitis sets in • Wt loss (suggestive of malignant change) • Cyanosis in advanced cases
- 83. • Finger clubbing (unique to asbestosis) • Dull percussion note in advanced cases • Stony dullness suggests effusion which itself suggests malignancy
- 84. Lung function tests • Initially normal • Later: – Decreased TLC, VC,RV – Increased RV/TLC% – Decreased FEV1 – Normal FEV1/FVC – Reduced gas transfer
- 85. Diagnosis • History of exposure • Clinical features • Radiological features • Lung function tests • Treatment – none • Prevention – Engineering measures to control dust – Personal protection – Medical examination – Health education
- 86. Diseases due to organic dusts 1. Byssinosis • Caused by inhalation of cotton dust • Early features include chest tightness experienced on mondays following weekend off or after a long holiday • May start soon after engagement or delay for a few years • Symptoms may last for a few hours only or may extend to Tuesday or even throughout the week • Unproductive cough • Breathlessness on exertion; worst on Mondays • Smoking aggravates the symptoms
- 87. Byssinosis contd • Diagnosis – History of exposure – Lung function tests • Decreased FEV1 • Decreased FVC • Decreased FEV1/FVC % – CXR is only used to exclude other diseases • Treatment – withdrawal • Prevention – Dust suppression including exhaust ventilation – Health education – Personal protection – -medical examination
- 88. 2. Bagassosis • An allergic condition caused by inhalation of dust from fibres left after sugar has been extracted from the cane • These fibres are used to make boarding for interior decoration of buildings and for thermal insulation • Not known if the dx is due to fibre proteins or to bacterial/fungal contaminants, many of which are found in the bagasse
- 89. Bagassosis contd • Clinical features – Symptoms occur in the form of acute respiratory illness about 8wks after exposure – Fever, breathlessness, cough and occasional haemoptysis – CXR shows features of bronchiolitis (excessive air trapping) – Symptoms gradually improve over a period of 6 wks at the end of which the CXR becomes clear
- 90. • Diagnosis – History of exposure – Clinical features – Radiological appearance • Treatment – as for allergic respiratory dxs – Antihistamines – Steroids – bronchodilators • Prevention – Antidust measures – Health education – Personal protection – Medical examination
- 91. 3. Farmer’s lung • Caused by inhalation of dust from mouldy hay or grain dust containing the thermophyllic actinomycetes- micropolyspora faeni • Characterized by general and respiratory signs/symptoms
- 92. • Repeated attacks cause pulmonary fibrosis • Long term complication is massive lung damage and cor pulmonale
- 93. Treatment and prevention • Withdrawal from exposure early in the course of the disease leads to resolution • Once pulmonary fibrosis occurs it cannot be reversed • Prevention – Health education -Personal protection -Regular med exam.
- 94. 4. Bird fancier’s disease/Chicken breeders disease • Caused by inhalation of protein dust from the furs of the birds • Characterized by dry cough, breathlessness and cyanosis at rest • In between exposures the worker feels better
- 95. • Chest X ray may show diffuse micronodular shadows • Both FEV1 and VC are reduced, FEV1/VC is normal
- 96. Treatment and prevention • Early stages and in mild cases, withdrawal will suffice • In severe cases patient may require steroids, oxygen etc
- 97. Occupational skin diseases • Dermatitis due to exposure to trauma, friction eg the hard palms of labourers and farmers • Dermatitis from exposures to physical agents like heat, cold, radiation, electricity, sunlight resulting in radiation burns • Dermatitis from organic and inorganic chemicals
- 98. • Dermatitis from plants and plant products like resins • Dermatitis from infective agents, insect bites, mites etc • Occupational skin cancers
- 99. Occupational poisons • Lead poisoning – Both organic and inorganic forms • Sources of exposure • Inorganic – Paint industries, welding of lead painted metals, lead acid battery industries, road side battery chargers, lead smelting plants, rubber manufacturing industries
- 100. • Organic lead – Lead petroleum industries • Route- inhalation and ingestion
- 101. presentation • Inorganic lead poisoning (mostly chronic) – Abdominal colic – Peripheral neuropathy – Anaemia– mild with exaggerated skin pallor – Lead (blue) line in the gums – Encephalopathy • Organic lead – Both acute and chronic in presentation – Encephalopathy
- 102. Diagnosis • Inorganic lead poisoning – Increased urinary lead (>0.2mg/l) – Increased serum and urinary deltaminolevulenic acid – Anaemia with punctate basophylia • Organic lead poisoning – Work history – Symptoms and signs of encephalopathy
- 103. management • Inorganic lead – Remove from further exposure – Give BAL(2,3-dimecaptopropanol) or calcium EDTA to chelate the lead (British anti-lewisite) • Organic – Removal from work – Give symptomatic treatment
- 104. Mercury poisoning • Cause: absorbed as elemental mercury or as a mixture • Sources of exposure – Leader felting(Hat making), thermometer, sphygmomanometer, electric filament, dental filler work place, mercurial insecticide work place etc • Route of entry- inhalation, ingestion and skin absorbtion
- 105. presentation • Acute poisoning – Oral, pharyngeal and laryngeal corrosion, pain – Abdominal cramps, nausea & vomiting • Chronic(industrial) poisoning – Salivation, stomatitis, diarrhoea, tremors, ataxia, irritability, apprehension, withdrawal & depression
- 106. Presentation contd • Cortical blindness, peripheral neuropathy, hens walk, nephritis • Diagnosis – Occupational history and symptoms
- 107. management • Removal from exposure • BAL (dimercaptopropanol) for chelation or penicillamine therapy
- 108. Health hazards/diseases of agric workers • Biological • 1.Bacteria-bovine TB -anthrax -brucellosis 2.Parasites -schistosomiasis -ankylostomiasis - necator americanus -guinea worm
- 109. • 3. viruses – Rabies, human cases of avian influenza, lassa fever • others -tetanus -snake bite -psittacosis -farmer’s lung -bagassosis - bird fancier’s disease
- 110. Chemical • Fertilizers • Preservatives • Pesticides e.g herbicides, rodenticides, insecticides
- 111. Paraquate and diquate (gramoxone) • Free O radical releasing and oxidizing agents • Enters the body through inhalation, ingestion and skin absorption • Kills by acute parenchymal inlammation of the lungs
- 112. Halogenated hydrocarbons eg DDT, dieldrin etc • Come in liquid or powder form • They are neurotoxic and produce chronic peripheral neuropathy • Rarely acute poisoning with anxiety and nervousness • Poor biodegradability, unfriendly to environment
- 113. management • Acute poisoning- withdrawal symptomatic treatment • Chronic poisoning- very unrewarding, best prevented
- 114. Organophosphates(parathion etc) • Acetyl cholinesterase inhibitor insecticides • Absorbed by inhalation and skin absorption • Cause- excessive salivation, lacrimation, nervousness, tremors, spasm and peripheral neuropathy
- 115. management • Acute poisoning- remove from exposure • Give atropine • If you are sure its organophosphate poisoning and not carbamate then give pralidoxime(specific antidote)
- 116. carbamates • Similar to organophosphates in action and effects except that they are from a different family • Pralidoxime is not an antidote for this group and in fact worsen its effects
- 117. Physical hazards • Excessive heat from the sun- heat exhaustion, heat stroke etc • Excessive cold- frost bite • Noise from aging machines • Poor or excessive lighting • Flooding • drowning
- 118. Mechanical • Dermatitis from tools and machines • Cuts from hoes and cutlasses and their complications • Backache from bending • Accidents with tractors and harvesters • Fishing boats capsiding
- 119. Psychosocial • Separation from home and family • Poor productivity • Job insecurity (in the face of conflicts) • Poverty • Loneliness • STIs • Poor social facilities • Poor/absent health facilities
- 120. Occupational diseases and the legislaton • Technological change New hazards (Disasters) • Recognition by medical science Social reformers bring to public attention • Resistance by vested interests Legislation to enlarge employer’s accountability for the hazards of work
- 121. Occupational legislation • Workmen’s ordinance 1941 • Replaced by workmen’s compensation decree of 1987 and amended in 1990, 2004 • Repealed and re-enacted in 2010 as “Employee’s compensation Act 2010”
- 122. definition • “ a person shall be deemed a workman if he enters into or is working under a contract of service or apprenticeship with an employer whether by way of manual labour, clerical work or otherwise, and whether the contract is expressed or implied, is oral or in writing”
- 123. The law provides for the following • Employer’s liability for compensation for death, injury, disease or disability resulting from occupational exposure whether in the course of work or after but can be traced to the work • Establishment of a fund for payment of compensation domiciled at NSITF
- 124. • Employers to contribute 1% of the employee’s pay into this fund • This fund is to be managed by the Nigerian Social Insurance Trust Fund (NSITF) • This is to minimize the burden of compensation payment on the employers • It also simplifies the procedure for payment of claims
- 125. • There is a “no fault” clause i.e its not necessary to determine whether the worker is at fault or not • The NSITF may constitute a medical advisory Board to assess claimants • An employee or his survivor is expected to report an incident of DIDD to the employer with 2 weeks of its occurrence • Employer should notify NSITF within 7 days
- 126. Labour law • Provides for: – contractual engagement in employment – Vacations and leaves – All women entitled to maternity leave irrespective of marital status – Minimum age of employment and age of retirement
- 127. Factory law • Provides for: • What constitutes a factory • Cleanliness • Overcrowding • Ventilation • Light • Drainage of floors • Sanitary accommodation • Factory inspection
Editor's Notes
- #4: OH studies the mode, and effects of occupational environmental hazards on human health- physical, chemical, biological, ergonomic and social. The effects are usually medical. It is concerned with how to mitigate or minimize the effect and prevent it from getting worse. Industrial hygiene is concerned with preventing exposure to occupational environmental hazards through engineering controls and good house keeping. It keeps the workplace environment clean, dry, pollution-free and hygienic