MBBS UG class on occupational health in three parts. part 1 includes introduction of occupational health, occupational diseases, ergonomics and Pneumoconiosis

2. Occupational Health-I
Dr Mamta G

3. What is Occupational Health?
• The promotion and maintenance of the highest degree of physical, mental and
social well-being of 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
• to summarize, the adaptation of work to man and of each man to his job

5. Ergonomics
• The term "ergonomics" is derived from the Greek ergon, meaning work and
nomos, meaning law.
• It simply means: "fitting the job to the worker".
• The object of ergonomics is "to achieve the best mutual adjustment of man
and his work, for the improvement of human efficiency and well-being.

6. Ergonomics example- student desks- which is best??
Plus type
Zero type
Minus type

7. Occupational environment- external/internal
3 types of interaction in a working environment:
(a) Man and physical, chemical and biological agents
(b) Man and machine
(c) Man and man

8. Man and phy/chem/bio agents
(1) Physical agents:
oHeat, cold, humidity, air movement, heat radiation, light, noise, vibrations
and ionizing radiation
oWorking and breathing space, toilet, washing and bathing facilities
(2) Chemical agents: chemicals, toxic dusts and gases
(3) Biological agents: viral, rickettsial, bacterial and parasitic agents which may
result from close contact with animals or their products, contaminated water,
soil or food.

9. Man and machine
• Accidents: unguarded machines, protruding and moving parts, poor
installation of the plant, lack of safety measures
• Working for long hours in unphysiological postures is the cause of fatigue,
backache, diseases of joints and muscles and impairment of the worker's
health and efficiency.

10. Man and man
• the human relationships amongst workers themselves on the one
hand, and those in authority over them on the other.
• 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, trade union activities, incentives

11. Occupational hazards
(a) Physical hazards
(b} Chemical hazards
(c} Biological hazards
(d) Mechanical hazards
(e} Psychosocial hazards

12. Physical hazards
• heat exposure -burns, heat exhaustion, heat stroke and heat cramps;
• the indirect effects are decreased efficiency, increased fatigue and enhanced
accident rates.
• Radiant heat is the main problem in foundry, glass and steel industries, while
heat stagnation is the principal problem in jute and cotton textile industry
• Eg.Kolar Gold Mines- 65C
• (20°C to 27°C) is the comfort zone in this country
• cold exposure-are chilblains, erythrocyanosis, immersion foot, and frostbite,
hypothermia

13. Heat

14. Cold

15. Light- poor
• acute effects of poor
illumination are eye strain,
headache, eye pain,
lachrymation, congestion
around the cornea and eye
fatigue.
• The chronic effects on health
include "miner's nystagmus“
https://youtu.be/dzlNscl5rWE

16. Light- excess
• Exposure to excessive
brightness or "glare" is
associated with
discomfort, annoyance
and visual fatigue.
Intense direct glare may
also result in blurring of
vision and lead to
accidents.

17. Noise
(i) Auditory effects which
consist of temporary or
permanent hearing loss.
(ii) Non-auditory effects which
consist of nervousness, fatigue,
interference with
communication by speech,
decreased efficiency and
annoyance.

18. Vibration
• From drills and hammers
• Vibration usually affects the
hands and arms.
• 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, elbows and shoulders.

19. Vibration S/E- White fingers

20. ULTRAVIOLET RADIATION
• Occupational exposure to ultraviolet
radiation occurs mainly in arc
welding.
• Such radiation mainly affects the
eyes, causing intense conjunctivitis
and keratitis (welder's flash).

21. Welder’s flash

22. Ionizing radiation
• In medicine and industry,
• e.g., X-rays and radio-active isotopes.
• Important radio-isotopes are cobalt 60 and phosphorus
• The radiation hazards comprise genetic changes, malformation,
cancer, leukaemia, depilation, ulceration, sterility and in extreme
cases death
• Explore effects of -
Chernobyl diasater 1986
Fukushima Disaster 2011

23. Chemical Hazards
• Local- dermatitis, eczema, ulcers and even cancer by primary irritant action
• Inhalation
oDust- mines, foundry, quarry, pottery, textile, wood or stone working
industries- cause Pneumoconiosis
oGases- simple gases, asphyxiating gases and anaesthetic gases
oMetals and compounds- lead, antimony, arsenic, beryllium, cadmium,
cobalt, manganese, mercury, phosphorus, chromium, zinc
• Ingestion- lead, mercury, arsenic, zinc·, chromium, cadmium, phosphorus
Contact
dermatitis by
cement

24. Other hazards
• Biological- The occupational diseases in this category are brucellosis,
leptospirosis, anthrax, hydatidosis, psittacosis, tetanus, encephalitis, fungal
infections, schistosomiasis and a host of others. Persons working among
animal products (e.g. , hair, wool, hides) and agricultural workers
• Mechanical- machinery, protruding and moving parts
• Psychosocial-
(a ) Psychological and behavioural changes : including hostility, aggressiveness,
anxiety, depression, tardiness, alcoholism, drug abuse, sickness, absenteeism
(b) Psychosomatic illhealth : including fatigue , headache; pain in the shoulders,
neck and back; propensity to peptic ulcer, hypertension, heart disease and rapid
aging

25. Break
http://nioh.org/
ICMR NIOH - Ahmedabad

26. Occupational diseases- diseases arising out of or during employment

29. Pneumoconiosis

30. Pneumoconiosis
Dust within the size range of 0.5 to 3 micron, is a health hazard
producing, after a variable period of exposure, a lung disease known as
pneumoconiosis,
which may gradually cripple a man by reducing his working capacity
due to lung fibrosis and other complications.

31. Pneumoconiosis
The hazardous effects of dusts on the lungs depend upon a number of
factors such as
(a) chemical composition
(b) fineness
(c) concentration of dust in the air
(d) period of exposure
(e) health status of the person exposed

32. no cure for the pneumoconiosis is known
it is essential to prevent these diseases

33. Silicosis
• Caused by inhalation of dust containing free silica or silicon dioxide
• First reported in India from the Kolar Gold Mines (Mysore)
• Seen in mining industry (coal, mica, gold, silver, lead, zinc, manganese
and other metals), pottery and ceramic industry, sand blasting, metal
grinding, building and construction work, rock mining, iron and steel
industry
• Incubation period -few months to 6 years

35. Clinical features
• Dense “nodular” fibrosis, the nodules ranging from 3 to 4 mm
• Early manifestations-irritant cough, dyspnea on exertion and pain in the chest.
• Advanced disease- impairment of total lung capacity (TLC)
• X-ray of the chest shows "Snow-storm" Appearance
• Silicotics are prone to tuberculosis, a condition called Silico-tuberculosis
• Sputum in silico-tuberculotics rarely shows tubercle bacilli

36. Snow storm appearance on X ray

37. No effective treatment for silicosis
• Fibrotic changes that have already taken place cannot be reversed.
• The only way that silicosis can be controlled (if not altogether eliminated) is by
(a) rigorous dust control measures, e.g., substitution, complete enclosure,
isolation, hydroblasting, good house-keeping, personal protective measures
(b) regular physical examination of workers
• Silicosis is a notifiable disease under the Factories Act 1948 and the Mines Act
1952.

38. of dust

39. Eg. Wet cutting of concrete

40. Personal protection (never as the only method)

41. Anthracosis= Coal Miner’s pneumoconiosis
• Two general phases–
(1) the first phase is simple pneumoconiosis- little ventilatory impairment.
• This phase may require about 12 years of work exposure for its development
(2) the second phase is characterised by progressive massive fibrosis (PMF)
• This causes severe respiratory disability and premature death.
• PMF can develop even without further coal exposure after first phase

44. Anthracosis
• Risk of death among coal miners is nearly twice that of the general
population
• Coal-miners' pneumoconiosis is a notifiable disease in the Indian
Mines Act of 1952, and also compensatable in the Workmen's
Compensation (Amendment) Act of 1959

45. Byssinosis
• Inhalation of cotton fibre dust over long periods of time
• Symptoms are chronic cough and progressive dyspnoea, ending in
chronic bronchitis and emphysema

46. Bagassosis
• Caused by inhalation of bagasse or sugarcane dust
• Due to a thermophilic actinomycete -Thermoactinomyces sacchari
• The sugarcane fibre is used in the manufacturing of paper, cardboard and rayon
• Symptoms- breathlessness, cough, haemoptysis and slight fever.
• Initially -acute diffuse bronchiolitis. X ray- mottling in lungs or shadow
• If left untreated, there is diffuse fibrosis, emphysema and bronchiectasis.

47. Bagasse

48. PREVENTIVE MEASURES
(1) DUST CONTROL : use wet process, enclosed apparatus, exhaust ventilation etc.,
(2) PERSONAL PROTECTION : masks or respirators with mechanical filters or with
oxygen or air supply
(3) MEDICAL CONTROL : Initial medical examination and periodical medical check-
ups of the workers.
(4) BAGASSE CONTROL: By keeping the moisture content above 20 per cent and
spraying the bagasse with 2 per cent propionic acid, a widely used fungicide

49. Asbestosis
• Asbestos(silicates) = silica combined with Mg/ Fe/ Ca/ Al/ Na
• Asbestos is used in the manufacture of asbestos cement, fire-proof textiles,
roof tiling, brake lining, gaskets
• Asbestos enters the body by inhalation, and fine dust deposits in the alveoli.
The fibres are insoluble.
Serpentine/chrysolite type Amphibole type
90% of asbestos 10%
hydrated magnesium silicate contains little magnesium and has diff varieties

52. Asbestosis
• The dust deposited in the lungs causes -
opulmonary fibrosis leading to respiratory insufficiency and death
ocarcinoma of the bronchus
omesothelioma of the pleura or peritoneum
ocancer of the gastro-intestinal tract
• The disease appear after 5 to 10 years of exposure
• The fibrosis in asbestosis is due to mechanical irritation, and is peri-
bronchial, diffuse in character, and basal in location in contrast to
silicosis in which the fibrosis is nodular in character and present in
the upper part of the lungs.

53. Asbestosis
• Characterized by dyspnoea out of proportion to the clinical signs in
the lungs.
• In advanced cases, there may be clubbing of fingers, cardiac distress
and cyanosis.
• The sputum shows "asbestos bodies" which are asbestos fibres
coated with fibrin.
• An X-ray of the chest shows a ground-glass appearance in the lower
two-thirds of the lung fields.
• Once established, the disease is progressive even after removal of
the worker from contact

54. Ground Glass Appearance on X Ray

55. Asbestos bodies

57. Asbestosis
• The preventive measures consists of :
(1) use of safer types of asbestos (chrysolite and amosite)
(2) substitution of other insulants: glass fibre , mineral wool, calcium
silicate, plastic foams, etc.
(3) rigorous dust control
(4) periodic examination of workers; biological monitoring (clinical, X-
ray, lung function)
(5) continuing research

58. Farmer’s lung
• Due to the inhalation of mouldy hay or grain dust
• In grain dust or hay with a moisture content of
over 30 per cent bacteria and fungi grow rapidly,
causing a rise of temperature to 40 to 50 deg. C.
• This heat encourages the growth of thermophilic actinomycetes, of
which Micropolyspora faeni is the main cause of farmer's lung .
• The acute illness is characterized by general and respiratory symptoms
and physical signs.
• Repeated attacks cause pulmonary fibrosis and inevitable pulmonary
damage and cor pulmonale.

59. Mouldy Hay and Grain Dust

60. End of Occupational Diseases -I
Q1. Identify the pneumoconiosis and the characteristic X ray features shown in image A and B.
Q2. Name two occupational diseases caused by Thermophilic actinomycetes.
A B