Occupational hazards in Public Health perspective and Occupational hazards in Dentistry

2. Seminar - 8
Dr. Nabeela Basha
2

3. Contents:
 Introduction
 Historical background
 Definition
 Health of workers
 Occupational Hazards
 Occupational Cancer
 Occupational Hazards of Agricultural Workers
 Accidents in Industry
 Sickness Absenteeism
 Prevention & control of occupational diseases
 Ergonomics
3

4.  Occupational Hazards in Dentistry.
 Conclusion
 Previous year questions
 References
4

5. Introduction
5

6. Harry McShane,
age 16 years, 1908.
 Had his left arm pulled off near
shoulder, and right leg broken
through kneecap, by being caught
on belt of a machine in Spring
factory in May 1908. He had been
working in factory more than 2 yrs.
 No attention was paid by
employers to the boy either at
hospital or home according to
statement of boy's father. No com-
pensation. Location: Cincinnati,
Ohio.
http://www.loc.gov/pictures/item/ncl2004000031/PP/
6

7. HISTORICAL BACKGROUND
 A review of the historical background of occupational
diseases and occupational environment brings to light the
3 distinct phases of development and may be designated
as:
Ramazzini Phase
Post-Ramazzini
Phase
• Hippocrates – lead
toxicity in miners.
• Galen – miners,
tanners, chemists
• Father of
Industrial
hygiene
• Gave two
famous exhortations
• Legislations in England
& other European
countries
• 1930 – industrial
hygiene
• 1940 – importance
realized
7

8. Definition
 Occupational health should aim at the promotion and
maintenance of the highest degree of physical, mental and social
well being of the workers in all occupations; the prevention
among workers of departures from health caused by their
working conditions; the protection of workers in their
employment from risks resulting from factors adverse to health;
the placing and maintenance of the worker in an occupational
environment adapted to his physiological and psychological
equipment and to summarize the adaptation of work to man and
of each man to his job.
(ILO/WHO 1950 and revised in 1996)
8

9. Preventive medicine and occupational health have the
same aim –
 The prevention of disease and maintenance of the
highest degree of physical, mental and social well-
being of workers in all occupations;
Levels of application: Health promotion, specific
protection, early diagnosis and treatment,
disability limitation and rehabilitation.
9

10. Occupational Health is application of preventive
medicine in all places of employment.
10

11. HEALTH OF THE WORKER
 Factors that influence the health of the population also
apply equally to industrial workers i.e. housing, water,
sewage and waste disposal ,nutrition and education.
 Aim: Occupational health is to provide a safe
‘occupational environment’ -to safeguard the health of
the workers and to increase industrial production.
11

12. OCCUPATIONAL ENVIRONMENT
 Occupational Environment is the sum of external
conditions and influences which prevail at the place of
work and have a bearing on the health of working
population.
Occupati
onal
Environm
ent
Man and
physical ,
chemical and
biological agents
Man and
Machine
Man and Man
12

13. Man and physical, chemical and
biological agents
Physical agents :-
 The physical factors - adverse to health are heat, cold
,humidity , air movement ,heat radiation, light, noise,
vibrations and ionizing radiation
 Factors act in different ways on the health and efficiency
of the workers -singly or different combinations.
 Amount of working and breathing space, toilet, washing
and bathing facilities are important.
13

14. Chemical Agents
 Comprise a large number of chemicals, toxic dusts and
gases which are potential hazards to the health of
workers.
Some chemical agents cause
 disabling respiratory illnesses
 injuries to the skin
 deleterious effect on the blood and other organs of the
body.
14

15. Biological agents
 The workers may be exposed to viral, rickettsial,
bacterial and parasitic agents - close contact with
animals or their products, contaminated water, soil or
food.
15

16. Man and Machine
 Industry or factory implies the use of machines driven by
power with emphasis on mass production.
 Unguarded machines, protruding and moving parts, poor
installation of plant, lack of safety measures -causes of
accidents.
 Working- long hours in unphysiological postures -causes
fatigue, backache, diseases of joints and muscles and
impairment of worker’s health & efficiency.
16

17. Man and man
 Numerous psychological factors operate at place of work.
 These are human relationships amongst workers
themselves on the one hand and those in authority over
them on the other.
 Psychological factors - type and rhythm of work, work
stability, service conditions, job satisfaction, leadership
style, security, workers participation, communication,
system of payment, welfare conditions, degree of
responsibility.
17

18.  Occupational environment of the worker can not be
considered apart from his domestic environment both
are complimentary to each other.
 Ecological approach -occupational health represents a
dynamic equilibrium or adjustment between the
industrial worker and occupational environment.
18

19. OCCUPATIONAL HAZARDS
Occupational
hazards
Physical
hazards
Chemical
hazards
Biological
hazards
Mechanical
hazards
Psychosocial
hazards
19

20. Physical hazards
Physical hazards
High Temperature
And
Low Temperature
Low Pressure
Vibration
Vibrations
Noise
Ionizing radiation
Light
Physical
hazards
High
Temperature
And
Low Temperature
Low
Pressure
Vibration
Vibrations
Noise
Non Ionizing
radiation
Light
20

21. Heat and Cold
 Common physical hazard in most of industries.
 Direct effect as heat stroke, heat exhaustion and
heat cramp.
 Indirect effect are decreased efficiency, increase
fatigue and enhanced accident rates.
 The Indian factories act has not laid down any
specific temperature standard.
21

22.  Occupational exposure to extremely low temperature
is experienced by divers, fishermen, dairy workers,
refrigerator repairmen, etc.
 Important hazards associated with cold works are
chillbains, trench foot and frostbite.
 General hypothermia is common.
22

23. Light
 Workers may be exposed to risk of poor illumination or
excessive brightness
 The acute effect of poor illumination are eye strains,
headache, eye fatigue, eye pain, lacrimation.
 The chronic effects -miner’s nystagmus
 Exposure to brightness or glare -discomfort annoyance and
visual fatigue.
 Intense direct glare - blurring of vision and lead to
accidents. Sufficient and suitable lighting, natural and
artificial whenever persons are working.
23

24. Noise
 Noise is a health hazard in many industries.
 Auditory effects - temporary or permanent hearing loss
 Non-auditory effects -nervousness,
fatigue, interference with communication
by speech, decreased efficiency and annoyance.
 The degree of injury -depends on intensity and frequency
range, duration of exposure and individual susceptibility.
24

25. Vibration
 Vibration- frequency range 10 to 500Hz - tools such as
drills and hammers.
 Vibration usually affects the hands and arms.
 After some months or years of exposure, the fine blood
vessels of the fingers may become increasingly sensitive
to spasm (white fingers)
 Exposure to vibration may also produce
injuries of the joints of the hands and shoulders.
25

26. Ultraviolet radiation
 Occupational exposure to ultraviolet radiation, mainly
affects the eyes, causing intense conjunctivitis and
keratitis(welder’s flash)
 Symptoms - redness of the eyes and pain, these usually
disappear in few days with no permanent effect on the
vision or on the deeper structures of the eye.
26

27. Ionizing Radiation
 Increasing application in medicine and industry
Eg. X-rays and radioactive isotopes (cobalt 60,P32)
 Tissues - bone marrow are more sensitive , hazardous to
genes when the gonads are exposed.
 Radiation hazards -genetic changes, malformation,
cancer, leukemia, depilation, ulceration, sterility, and in
extreme cases death.
27

28.  The International commission of Radiological
Protection has set the maximum permissible level of
occupational exposure at 5 rem per year to the whole
body.
28

29. Biological hazards
 Workers - exposed to infective and parasitic agents at
the work place.
 It may cause brucellosis, leptospirosis, anthrax,
hydatidosis, tetanus, fungal infection such as
schistosomiasis.
 Persons working among animal products and
agricultural workers are specially exposed to biological
hazards.
29

30. Chemical hazards
 The chemical hazards in various occupations can be due
to gases, vapours, fumes, mists, dust, etc.
 The risk associated with occupational exposure to gases
was first shown in mines.
 Gases can cause damage due to: Asphyxiation, Irritant
action, Toxic action, Necrotization.
 The gases that cause occupational health hazards are:
1. Asphyxiant gases: Carbon Monoxide, Hydrogen sulfide
2. Irritant gases: Ammonia, Chlorine, Sulphur dioxide
3. Toxic gases: Arsine
4. Inert gases: Methane, Carbon dioxide.
30

31. PNEUMOCONIOSIS
 This is a special type of chemical hazard produced by
occupational exposure to dusts. These are categorized as:
1. Major pneumoconiosis: Silicosis, Asbestosis,
Anthracosis.
2. Minor pneumoconiosis: Bagassosis, Byssinosis,
Farmer’s Lung.
31

32. Silicosis
 The major cause of permanent disability and mortality.
 It is caused by inhalation of dust containing free silica
or silicon dioxide (SiO2).
 Reported in India from the Kolar Gold mines Mysore
in 1947.
 Mica mines of Bihar out of 329 miners examined
34.1% were found suffering from silicosis. Ceramic
and pottery industry -incidence depends upon chemical
composition of the dust, size of the particles duration
of exposure and individual susceptibility.
32

33.  Silicosis is characterized by a dense nodular fibrosis the
nodules ranging from 3 to 4 mm in diameter.
 Impairment of total lung capacity (TLC) is commonly
present.
 X-ray of chest shows snow storm appearance
 The only way silicosis can be controlled is by
1. Rigorous dust control measures such as substitution,
complete enclosure, isolation good housekeeping.
2. Regular physical examination of workers
Silicosis was made a notifiable disease under the factories act
1948 and the Mines Act 1952.
33

34. Asbestosis
 Asbestos is used in manufacture of cement, roof tiling,
brick lining.
 Enter in the body by inhalation and fine dust may be
deposited in alveoli.
 Amongst its different varieties, Blue Amphibole variety
is more hazardous, which causes fibrosis of lung tissue.
 Asbestosis with cigarette smoking – great risk of
bronchial cancer.
34

35.  Disease is characterized by dyspnoea.
 Sputum - show asbestos bodies.
 Ground – glass appearance on radiography.
 Preventive measures.
1. Substitution of other insulants eg :glass fibres calcium
silicate etc.
2. Rigorous dust control
3. Periodic examination
4. Continuing research
35

36. Anthracosis
 Seen among Coal workers in coal mining.
 Manifests as simple pneumoconiosis or progressive
massive fibrosis (PMF).
 Respirable coal dust concentration should not exceed
2mg/m3 .
 Anthracosis has been declared a notifiable disease under
the Indian Mines Act 1952 also compensable in the
Workmen’s Compensation (Amendment)Act of 1959.
36

37. Byssinosis
 It is due to inhalation of cotton fiber dust over long
periods of time.
 Symptoms are chronic cough and progressive dyspnoea,
ending chronic bronchitis and emphysema.
 Incidence of byssinosis is reported to be 7-8% -surveys
carried out in Mumbai, Ahmedabad and Delhi.
37

38. Bagassosis
 Caused by inhalation of bagasse or sugar cane dust.
 1st reported in India by Ganguli and Pal(1955) in
cardboard manufacturing firm in Kolkata.
 Bagassosis is due to thermophilic actinomycete for
which name Thermoactinomyces sacchari.
 Symptoms -breathlessness ,cough, haemoptysis and
slight fever.
38

39. Farmer’s Lung
 Is due to the inhalation of moldy hay or grain dust
 In grain dust or hay with a moisture content of over 30%
bacteria and fungi grow rapidly causing a rise of
temperature to 40 -50 deg.C
 This heat encourages the growth of thermophillic
actinomycetes of which Micropolyspora faeni is main
cause of farmer’s lung.
 Repeated attacks cause pulmonary fibrosis.
39

40. Lead poisoning
 More industrial workers are exposed to lead than any other
toxic metal.
 Mode of absorption:-
1. Inhalation: fumes or dust of lead.
2. Ingestion:may be ingested in small quantities from lung,
food or drink by contaminated hands.
3. Skin: organic compound such as tetraethyl lead
40

41.  Body Stores
1. Body store of lead in an average adult is 150-400 mg and
blood vessels average about 25 microgm/100ml.
2. Increase up to 70microgm /100ml - clinical symptoms
3. Normal adult ingest : 0.2-0.3mg of lead per day- food and
beverages.
41

42.  Lead poisoning or plumbism is different in inorganic and
organic lead exposures
 Toxic effect of inorganic lead exposure- abdominal colic,
obstinate constipation ,loss of appetite ,wrist drop, foot drop.
 Toxic effect of organic lead compound - CNS – insomnia,
headache, mental confusion, delirium etc.
 Diagnosis
1. History
2. Clinical features :Loss of appetite, headache, abdominal
cramps, constipation, joint and muscular pains, blue lines on
gums.
42

43. Laboratory tests
 Coproporphyrin in urine(CPU) ; in non exposed
person it is less than 150 microgram/ litre.
 Amino levullinic acid in urine (ALAU) if exceeds 5
mg / L indicates clearly lead absorption.
 Basophilic stippling of RBC
 Lead in blood and urine:- over 0.8 mg /L in urine and
70 microgm/100ml in blood.
43

44.  Preventive measures
1. Pre placement examinations
2. Substitution
3. General & Local exhaust ventilation to reduce
particulate lead concentrations.
4. Modification: Moistening of earth in Lead mining.
 Management
1. A saline purge will remove unabsorbed lead from gut
2. D-penicillamine- chelating agent promotes lead
excretion in urine.
Lead poisoning is a notifiable and compensable disease in
India.
44

45. OCCUPATIONAL CANCER
 Occupational cancer is a serious problem in industry.
 The sites of the body most commonly affected are skin,
lungs, bladder and blood forming organs.
45

46. Skin cancer
 Percival Pott was first to draw attention to cancer of
scrotum in chimney sweeps in 1775.
 Coal tar was responsible to produce cancer of skin and
scrotum.
 Nearly 75% occupational cancers are skin cancer.
 Commonly found in gas workers ,cake oven workers,
tar distillers, oil refiners.
46

47. Lung cancer
 It is hazard in gas industry, asbestos industry, nickel
and chromium work ,arsenic roasting plants and in
mining of radioactive substances
 Arsenic, beryllium and isopropyl oil are suspected
carcinogens
 More than nine-tenths of lung cancer are attributed to
tobacco smoking, air pollution and occupational
exposure.
47

48. Cancer bladder
 Cancer bladder was first noticed in man in aniline
industry in 1895, later it was found in rubber industry.
 Cancer bladder caused -aromatic amines, which are
metabolized in the body and excreted in urine.
 Industries associated with cancer bladder are the dye-
stuffs and dyeing industry, rubber, gas and the electric
cable industries.
 Possible carcinogens beta napthylamines, benzidine,
paraamino-diphenyl, and auramine.
48

49. Leukemia
 Exposure to benzol, roentgen rays and radioactive
substance give rise to leukemia.
 Benzol is a dangerous chemical and is used as solvent
in many industries.
 Leukemia may appear long after exposure has ceased.
49

50. Characteristics of occupational cancer
 Appear after prolong exposure.
 The period between exposure and development of the
disease may be as long as 10-25years.
 The disease may develop after cessation of exposure.
 The localization of tumours is remarkably constant in
any one occupation
50

51. Control of industrial cancer
 Elimination or control of industrial carcinogens,
technical measures like exclusion of the carcinogen
from the industry, well designed machinery, closed
system of production, etc.
 Medical examination.
 Inspection of factories.
 Notification
 Licensing of establishments
 Personal hygiene measures
 Education of workers and management
 Research
51

52. Occupational hazards of Agricultural
workers
 Occupational health in agricultural sector is a new concept.
 Agricultural workers have a multitude of health problems a fact
which is often forgotten because of the widespread misconception
that occupational health is mainly concerned with industry and
industrialized countries.
 The hazards to which a worker in agricultural activities is exposed
are:-
1. Physical hazards
2. Chemical hazards
3. Biological hazards
4. Accidents
52

53. Accidents in industry
 Accident are common feature in most industries In fact
some industries are known for accidents e.g. mining
specially coal , construction work.
 It was estimated that nearly 3 million men are lost
yearly due to industrial accidents.
 Causes are human and environmental
1. Physical
2. Physiological factors
3. Psychological factors.
 Environmental factors are the temperature, poor
illumination, humidity, noise unsafe machines.
 Unsafe machine account for 10-20% of all accident.
53

54. Prevention
 98% accidents are preventable
 The principle of accident prevention are
1. Adequate pre-placement examination.
2. Adequate job training
3. Continuing education
4. Ensure safe working environment
5. Establishment of safety department in organization
under competent safety engineer
6. Periodic survey for finding out hazards
7. Carefully reporting and maintenance of records and
publicity.
54

55. Sickness Absenteeism
 Sickness absence is important health problem in industry.
As the production techniques become more sophisticated ,
absenteeism tends to increase.
 Absenteeism is a useful index in industry to assess the state
of health of workers and their physical, mental and social
well being.
Causes
1. Economic causes 3. Medical causes
2. Social causes 4. Non occupational causes
55

56. Prevention & Control of
Occupational diseases
1. Medical measures
2. Safety / Engineering measures
3. Legislative measures
57

57. Medical measures
 Pre –placement examination
 Periodical examination
 Medical care services
 Health care
 Notification
58

58. Engineering / Safety measures
1. Design of building
2. Good housekeeping
3. General ventilation
4. Mechanization
5. Substitution
6. Dusts
7. Enclosure
8. Isolation
9. Local exhaust
ventilation
10.Protective devices
11.Environmental
monitoring
12.Statistical monitoring
13.Research
59

59. Legislation
 The most important factory laws in India are
1. The Factories Act 1948
2. The Employees State Insurance Act 1948
60

60. The Factories Act, 1948
1st Indian factories act-1881.
Revised in year 1987.
A factory -defined as a place using power, employs 10 or
more workers, or 20 or more workers without power or were
working any day of the preceding 12 months.
Health, Safety and Welfare(chapter III, IV IVA and V)
A minimum 500Cu.ft of space for each worker has been
prescribed.
61

61. Precaution should be taken for ensuring the safety of workers.
State government are empowered to prescribe maximum
weights may be lifted or carried out by men women and
children.
The 1976 amendment (section 40 B) -Safety Officers in every
factory wherein 1000 or more workers are ordinarily
employed
Crèches - factory wherein more than 30 women workers are
ordinarily employed
62

62. Employment for Young Person
 Prohibits employment of children below -14 years .
 Declares Persons between ages 15-18 to be adolescents.
 Adolescents should be certified by the certifying surgeons
 Adolescents employee is allowed to work only between 6 A.M.
& 7P.M.
 Maximum 48 working hours per with rest for at least ½ hour
after 5 hours of continuous work.
 For adolescents the hours of work have been reduced from 5 to
4and ½ hours.
63

63. The Employees State Insurance, Act
1948
 The ESI Act was passed in 1948, amended in 1975, 1984,
1989 and 2010.
 An important measure of social security and health insurance
in this country.
 Provides for certain cash and medical benefits in case of
sickness, maternity and employment injury.
 The ESI Act applies to any premises, where 10 or more
persons are employed
64

64.  Under these enabling provisions, most of the State Govts.
have extended the ESI Act to Medical and Educational
Institutes, shops, hotels, restaurants, cinemas, preview
theatres, motor transport undertakings, newspaper and
advertising establishments etc., employing 10 or more
persons.
 With effect from 1-05-2010, the Act covers all employees
getting upto Rs.15,000 per month.
 This has been further revised to Rs.21,000 per month as per
notification of ESIC on 6-09-2016.
65

65.  Administration of the ESI Scheme-ESI corporation
 The scheme is run by contributions by employees and
employers and grants from central Govt and state Govt.
 Employer contributes 4.75%, employee contributes 1.75% of
the wages.
 State govt share of medical expenses is 1/8th of total cost of
medical care.
 ESI corporation’s share is 7/8th of total cost of medical care
66

66.  Medical Benefit- Medical benefit consists of "full medical
care" including hospitalization, free of cost, to the insured
persons in case of sickness, employment injury and
maternity.
 Medical care is provided either directly through the agency
of ESI hospitals and dispensaries, or indirectly through a
panel of private medical practitioners (panel system)
appointed as "insurance medical practitioners".
67

67.  Sickness Benefit - It consists of periodical cash payment to
an insured person in case of sickness, if his sickness is duly
certified by an Insurance Medical Officer or Insurance
Medical Practitioner.
 The benefit is payable for a maximum period of 91 days, in
any continuous period of 365 days, the daily rate being about
50% of the average daily wages.
68

68.  Maternity Benefit- The benefit is payable in cash to an
insured woman for confinement/miscarriage or sickness
arising out of pregnancy/ confinement or premature birth of
child or miscarriage.
 For confinement, the duration of benefit is 26 weeks, for
miscarriage 6 weeks and for sickness arising out of
confinement etc. 30 days.
69

69.  Disablement Benefit- The Act provides for cash payment,
besides free medical treatment, in the event of temporary or
permanent disablement as a result of employment injury as
well as occupational diseases.
 The rate of temporary disablement benefit is about 70 per
cent of the wages as long as the temporary disablement lasts.
70

70.  Dependants’ Benefit- In case of death, as a result of
employment injury, the dependants of an insured person are
eligible for periodical payments.
 An eligible son or daughter is entitled to dependant's benefit
up to the age of 18: the benefit is withdrawn if the daughter
marries earlier.
 Funeral expenses- Funeral benefit is a cash payment payable
on the death of an insured person towards the expenses on
his funeral, the amount not exceeding Rs. 10,000. (1.4.11)
71

71. Rajiv Gandhi Shramik Kalyan Yojna
 The ESI corporation has launched a new Yojna for the
employees covered under ESI scheme.
 This scheme provides an unemployment allowance for the
employees covered under ESI scheme who are rendered
unemployed involuntarily due to retrenchment/ closure of
factory etc. after fulfilling certain eligibility conditions. The
scheme came in to effect from 1st April 2005.
 Unemployment Allowance maximum period of 6 months.
72

72.  During this period person is eligible for medical care for
himself and family from ESI dispensaries, Panel clinics and
hospitals to which he /she was attached before unemployment.
73

74. Seminar – 8
(Session – 2)
Dr. Nabeela Basha
75

75. Contents:
 Introduction
 Historical background
 Definition
 Health of workers
 Occupational Hazards
 Occupational Cancer
 Occupational Hazards of Agricultural Workers
 Accidents in Industry
 Sickness Absenteeism
 Prevention & control of occupational diseases
76

76. Session - 2
 Ergonomics
 Occupational Hazards in Dentistry.
 Conclusion
 Previous year questions
 References
77

77. ERGONOMICS
 Well recognized discipline and constitutes an integral part of any
advanced occupational health service.
 Ergonomics –derived from Greek ergon-work and nomos-law.
 Simply means- “fitting the job to the worker”
 Object- “to achieve the best mutual adjustment of man and his
work ,for the improvement of human efficiency and well-being”
 Application of ergonomics has made significant contribution to
reducing industrial accidents and to overall health and efficiency
of the workers.
78

78. Occupational hazards in dentistry
Hazards
in
dentistry
Physical
Biological
Psychologi
cal
Chemical
Mechanica
l
79

79. Physical hazards
Heat
 Lack of maintenance of electrical equipment.
 Effects-painful shocks, burns, etc
Light
 Poor illumination-eye pain, eye strain, headache,fatigue etc.
 Excessive brightness- discomfort, annoyance, visual fatigue.
 Prevention-Sufficient and suitable lighting.
Noise
 High speed turbines, compressor, suction, ultrasonic dental
scaler.
 Auditory-temporary or permanent hearing loss.
 Non-auditory-fatigue, interference with communication by
speech, decreased efficiency and annoyance.
80

80. Ultraviolet radiation, computers, lasers
 Eyes are affected –conjunctivitis and keratitis.
 Radiation-X rays.
 International commission of radiological protection –
maximum permissive level of occupational exposure-5
rem per year to the body.
 Effects-erythema and dermatitis.
 Chronic-skin cancer and bone marrow suppression.
 Genetic effects-developmental defects in offsprings.
81

81. Radiation Protection and Prevention
 Goal-minimize radiation exposure of personnel and patients
 Recommendations for safety of practitioner:
 Buying of standard radiographic equipment –follows
National Council on Radiation Protection and
Measurements(NCRP) and ISI recommendations.
 Filtered beams and collimators should be used.
 Use of lead barriers between surgeon and X rays.2 mm thick
sheet.
82

82.  Use of barium plaster which absorbs scattered radiation.
 Lead aprons should be used.
 Thyroid shield for patients.
 Surgeons must use a film badge service provided by
Bhabha Atomic Research Centre (BARC) Mumbai for
personnel monitoring.
83

83. Sharps:
 Glassware and sharp needles, lancets, B.P blades,test
tubes are hazardous.
 Cuts, scratches, abrasions are potential locations for
infections.
Prevention:
 Handle with care
 Biomedical waste management.
84

84. 85
Post accidental management
 Remove the gloves
 Wash the site of injury under running water with soap and
water
 Avoid scrubbing and encourage bleeding and then protect
 Usually it is necessary to take blood specimen of both the
patient and the injured person- and tested for HIV

85. 86
IF THE PATIENT IS SEROPOSITIVE
FOR HIV……
 The health care worker should be counseled about the risk of
infection and evaluated clinically and serologically as soon as
possible after exposure. A baseline HIV test should be carried
out immediately.
 Advised to report and seek medical evaluation for any febrile
illness that may occur within 12 weeks of exposure.
 HIV test should then be repeated approximately 6 to 12
weeks after contamination.

86. 87
IF THE PATIENT IS SEROPOSITIVE
FOR HIV……
 Advised to follow recommendation for preventing
transmission of infection.
 During this period advise from HIV counselor is of utmost
importance, regarding domestic relation and procedure at
workplace.
 The practitioner should immediately be evaluated by a
physician.

87. Chemical Hazards
Mercury: may cause mercury-poisoning during amalgam
restoration.
It can be prevented by using precapsulated alloys, good
ventilation and proper mulling.
Methacrylates ; causes irritation to skin, eyes, allergic
dermatitis and asthma.
It can be prevented by using nitrile gloves.
Silica ; causes silicosis by inhaling free silica and silicon
dioxide in ceramic laboratories.
88

88. Formaldehyde
Used in clinical setup for disinfection.
Effects-Acute-eye and respiratory irritation from liquid and
vapor form.
Severe abdominal pain, nausea, vomiting and possible loss
of consciousness could occur.
Chronic- Laryngitis, bronchitis.
Latex glove
Covered with cornstarch powder –barrier against
pathogens.
Most professionals are allergic.
Effects-Urticaria
Prevention-non-latex gloves. Eg: vinyl or nitrile gloves.
89

89. Dealing safe with Mercury
 Use of water sprays, high velocity evacuation and rubber dam
to reduce exposure
 Dental staff should wear face-mask
 Carpeting and rugs should be avoided as it is a major
repository for mercury
 Never rinse elemental mercury down the drain or trash
 Never dispose elemental mercury in the sharp container or as
medical waste
 Keep the filling cool during removal
90

90. Biological Hazards
 Dentist can get infected by viruses, bacteria, fungi either
directly or indirectly i.e by cut, wound ,needle-stick injury,
aerosols of saliva, gingival fluid etc.
 Main entry points for infection are: epidermis of hands, oral
epithelium, nasal epithelium, epithelium of upper airways,
bronchial tubes, alveoli and conjunctival epithelium.
 Transmissible diseases –dental professionals are
HBV,HIV,HCV,HSV and Mycobacterium tuberculosis.
91

91. PSYCHOSOCIAL HAZARD
• Stress situations from dentist’s everyday work like meeting
high expectation of patient and emergency clinical situations
• This leads to increase tension, high blood pressure, tiredness,
depression and sleeplessness
• Dentists with their busy schedules will be deprived of social
interaction, spend less time with family leading to many
depression syndrome
• It can be prevented by space out professional work, having
sufficient rest, by interacting with family, doing exercise and
yoga.
92

92. Musculoskeletal Disorders
 At work-dentist assumes strained posture both
while standing and sitting close to patient - causes
overstress to spine and limbs, and peripheral nervous
system.
 Back pain syndrome, neck discopathy,
cervicoacromial pains, and carpel tunnel syndrome.
93

93. CARPAL TUNNEL SYNDROME is a defect of the median
nerve and cubital nerve. In its early phase, it is manifested as
paresthesia of the thumb and index finger which is
accompanied by disorders of the thumb and index finger as
well as by the atrophy of the thenar.
94

94. Ergonomics in Dentistry
 The scope of ergonomics in dentistry is large: it ranges
from chemistry between the dental team to lighting, noise
and odor conditions and naturally to the used equipment
and software.
 The treatment environment with the patient chair, dental
unit, operating light, dynamic and hand instrumentation,
cabinetry and peripheral equipment must be flexible.
95

95.  Dentists need to adapt and guarantee good working
postures, sufficient lighting and easy access to required
instrumentation and materials for different working
practices, clinical procedures and patient types.
96

96. Few guidelines of how to work..
 Student/clinician should be properly
seated in neutral posture
a) Feet should rest flat on floor
b) Angle between spine and the thighs
should be 90 to 110 degrees
c) Upper arms should be close to body
and shoulders should be maintained
in a horizontal line.
d) Elbow / forearm angle is close to 90º
97

97. e) Wrists should be in line with the fore-arm with no more than
20-30 degrees extension.
2. Patient should be seated such that oral cavity is at a height
equal to the height of seated clinician’s heart.
3. For Maxillary arch, should be such that chin should be up
and for mandibular arch, chin should be down.
4. Turn head of the patient towards left/right depending upon the
quadrants.
98

98. 5. Use light weight instrument with hollow or Round, textured
handles.
6. Color-coded instruments should be used as it makes
instrument identification easier reducing eye strain.
7. Dental chair should be constructed of rigid cast frame with
proper lumbar support that will not distort with time and use.
99

99. Recommendations:
 Ergonomic practices should be made compulsory in the
undergraduate curriculum.
 Unnecessary twisting ,placing instruments far from reach
and awkward positions should be strictly discouraged.
 Magnification aids should be used.
 Four handed dentistry should be promoted.
 Ergonomically designed instruments should be utilized-
larger handles to reduce pain and fatigue.
 Proper methods of lighting should be monitored among
students.
 Chairs that provide adequate adjustability must be used.
 Ergonomics awareness training should be given to
students.
100

100.  Occupational Safety and Health Administration (OSHA) is an
agency of the United States Department of Labor. It was
created by Congress under the Occupational Safety and
Health Act, signed by President Richard M. Nixon, on
December 29, 1970.
 Its mission is to prevent work-related injuries, illnesses, and
deaths by issuing and enforcing rules (called standards) for
workplace safety and health.
101

101.  Provide Hepatitis B immunization to employees without
charge within 10 days of employment.
 Require that universal precautions be observed to prevent
contact with blood and other potentially infectious material.
Saliva is considered to be a blood-contaminated body fluid in
relation to dental treatments.
 Implement engineering controls to reduce production of
contaminated spatter, mists and aerosols.
OSHA Regulations102

102.  Implement work practice control precautions to minimize
splashing, spatter or contact of bare hands with contaminated
surfaces
 Provide facilities and instructions for washing hands after
removing gloves and for washing skin immediately or as
soon as feasible after contact with blood or potentially
infectious materials.
 Prescribe safe handling of needles and other sharp items.
103

103.  Prohibit eating, drinking, handling contact lenses etc. in
contaminated environments. Ban storage of food and drinks
in refrigeration or other spaces where blood or infections
materials are stored.
 Place blood and contaminated specimen to be transported or
stored into suitable closed containers that prevent leakage.
 As soon as feasible after treatments attend to housekeeping
requirements including floors, sinks etc that are subject to
contamination.
104

104.  Provide written schedule for cleaning.
 Contaminated sharps are regulated waste, discard in hard
walled containers.
 Place reusable contaminated sharp instruments into a basket
in a hard-walled container for transportation to the clean-up
area. Personnel must not reach hands into containers of
contaminated sharps.
105

105. CONCLUSION
 Occupational health risks are present in every profession.
 With advent of advanced technology, no matter how
beneficial it is, can exert a negative impact on some
members of the population.
 The reality is to balance maximum benefit and minimum
harm to the population and wellbeing.
 Once identified and recognized as risk, new guidelines,
precautions and protocols should be rapidly instituted to
reduce or even eliminate the hazards.
106

106.  Application of ergonomics and administrative
measures contribute greatly in reducing the
occupational hazards in the professional groups.
107

107. PREVIOUS YEAR QUESTIONS
1. Discuss the various Occupational Hazards related to
Dental Practice and add a note on its control. (RGUHS
M.D.S. Degree Examination - April / May 2007) 20
marks.
2. Occupational hazards in Dentistry. (RGUHS M.D.S.
Degree Examination – October 2010) 10 marks.
3. Occupational hazards. (RGUHS M.D.S. Degree
Examination – May 2013) 10 marks.
108

108. REFERENCES
1. K. Park. Park’s Textbook of Preventive and Social medicine.
23th ed. Jabalpur: M/s Banarsidas bhanot; 2015.
2. MC Gupta and BK Mahajan. Textbook of Preventive and
Social Medicine. 3rd Edition 2003. Jaypee Brothers Medical
Publishers Ltd, New Delhi.
3. Dhaar G.M, Robbani I. Foundations of community medicine.
2nd ed. Elsevier publication, Noida; 2008.
4. P.Soben. Essentials of preventive and social medicine. 5th ed.
Arya publishing house, New Delhi; 2013.
109

109. 5. Hiremath SS. Textbook of Preventive and Community Dentistry. 3rd
edition. Elsevier Publishers, New Delhi; 2016.
6. V.V.R.Seshu Babu. Review in Community Medicine. 2nd edition.
Paras Medical Books Pvt Ltd, Hyderabad; 2011.
7. KN Abhishek, Jain J, Khanapure SC, M Shilpa. Ergonomics –
Work Smart, Be Safe!!. J Adv Med Dent Scie 2013;1(2):34-39.
8. Gopinadh A, KN Neelima Devi, Chiramana S, Manne P, Sampath
A, MS Babu. Ergonomics and musculoskeletal disorder: As an
occupational hazard in Dentistry J Contemp Dent Prac, March-April
2013;14(2):299-303.
110

110. 9. OSHA, US Department of labour Safety and health Administration
Technical Manual, Section VI, 1999: 1-12.
111