1. Physical hazards
Dr Majid Golabadi

2. OCCUPATIONAL HEALTH HAZARDS
Physical
Chemical
Biological
Ergonomic
Psychosocial

3. PHYSICAL HAZARDS Noise Temperature Vibration Radiation
Atmospheric pressure

4. Temperature
Heat
Cold

5. Noise
Hearing loss

6. Vibration
Whole body
Hand arm

7. Radiation Non-ionizing Ionizing EMF, Radiofrequency ,Microwave
Infrared (IR), Visible ,Ultraviolet
Ionizing
Alpha,ß,
X,gama

8. Atmospheric pressure
Compress
Decompression (caisson )

9. Radiation
Non-ionizing
Ionizing

11. Radiation is defined by:
Type
Photon energy
Wavelength
Frequency

13. The Electromagnetic Spectrum:

14. Non-Ionizing Radiation

16. EXTREMELY LOW FREQUENCY (ELF)
The generation, transport, and use of electricity are associated invariably with ELF fields.
ELF radiation was classified by IARC as ‘possibly carcinogenic to humans’ (Group 2B), based on the childhood leukemia association

17. RADIOFREQUENCY (RF)
A major difference between RF and ELF exposures is RF thermal effects.
erythema and a heating sensation acutely followed by hypertension and psychiatric symptoms lasting several months
Microwave-induced cataracts
Additional non-thermal effects of RF – behavioral alterations, changes in immune cells, and adverse reproductive outcomes.

18. Infrared Radiation (IR)
All objects with temperature above absolute zero emit IR radiation.

19. Injuries by IR Wavelength between 750 and 3million nm
Examples of exposures:
sun light, welding, glassmaking, drying and baking in consumer product

20. Injuries by IR Especially between 750-2000 nm Skin burn
Eye symptom(cornea,iris,lens)
Cataract (glassblowers, furnace workers)

21. Biologic systems exposed to IR experience a corresponding rise in the temperature of the absorbing tissue.
excessive ocular exposure to IR-A may lead to damage to the lens (cataracts),choroid and retina.
IR-B can damage the cornea, conjunctiva and aqueous humor.

22. Visible Radiatin

23. Injuries by Visible Radiatin
Between IR and UV
Wavelength between 400 and 750 nm
Eye symptom(especially retina in nm “blue light”)
Chronic exposure to excessively bright light may lead to premature degeneration of the cones responsible for color vision

24. Ultraviolet Radiation - UV
Ultraviolet Radiation (UV) is simply one form of energy coming from the sun
Sunlight contains 3 types of UV rays…

25. UV radiation • UV-A: 320-400 nm • UV-B: 280-320 nm • UV-C: 200-280 nm
Absorption by ozone and
oxygen in atmosphere is
wavelength dependent.
UV irradiance at surface:
• UV-A: 94%
• UV-B: 6%
• UV-C: 0%

26. Injuries by UV
UVA—causes skin aging & wrinkles. UVA rays pass effortlessly through the ozone layer.
UVB—causes sunburns, Photokeratoconjunctivities, cataracts, skin cancer. Melanoma may be associated with severe UVB sunburns. Most UVB rays are absorbed by the ozone layer.
UVC—these rays are the most dangerous. Fortunately, these rays are blocked by the ozone layer and don’t reach the earth.

27. Effects of UV Exposure
Eye Damage
Oklahoma State University

28. Eye Damage
Spending long hours in the sun with no eye protection may increase chance of developing cataracts.
UVB damage to the eyes is cumulative, so it is never too late to start protecting your eyes.

30. Effects of UV Exposure
Skin Damage
Oklahoma State University

31. Sunburn
Sunburn develops when the amount of UV exposure is greater than the protection your skin’s melanin can provide.

36. Skin Damage
There are about 1.3 million new cases of skin cancer in the U.S. each year, resulting in about 9,800 deaths.
Melanoma is one type of skin cancer. It is the most common cancer among women between the ages of 25 and 29.

37. Ionizing Radiation

38. Definition and types Two types:
Ability to disrupt atoms or molecules and produce ions, free radicals and biochemical lesions.
Two types:
Electromagnetic (X-ray, Gamma ray)
Particulate (neutron, Alfa particle, Beta particle …)

39. X-Rays and Gamma Rays Gamma and X radiation differ
by source: gamma rays comes
from the nucleus and X-rays
come from the electron orbits
they penetrate very deeply
Xrays are similar to gamma but with a longer wavelength
A person exposed to X-rays or gamma
rays does not become radioactive
This black and white photograph shows graphite meltdown that resulted in release of gamma rays.

40. Penetration Abilities of Different Types of Radiation
Alpha Particles
Stopped by a sheet of paper
Beta Particles
Stopped by a layer of clothing
or less than an inch of a substance (e.g. plastic)
Radiation
Source
Gamma Rays
Gamma Rays
Stopped by inches to feet of concrete
or less than an inch of lead
Alpha particles. Alpha particles do not penetrate the dead layer of skin and can be stopped by a thin layer of paper or clothing. If an alpha emitting radioactive material gets inside the body through inhalation, ingestion, or through a wound, the emitted alpha particles can cause ionization that results in damage to tissue.
Beta particles. Depending on its energy, beta radiation can travel from inches to many feet in air and is only moderately penetrating in other materials. Some beta radiation can penetrate human skin to the layer where new skin cells are produced. If high enough quantities of beta emitting contaminants are allowed to remain on the skin for a prolonged period of time, they may cause skin injury. Beta emitting contaminants may be harmful if deposited internally. Protective clothing (e.g., universal precautions) typically provides sufficient protection against most external beta radiation.
Gamma rays and x-rays (photons). Gamma rays and x-rays are able to travel many feet in air and many inches in human tissue. They readily penetrate most materials. Thick layers of dense materials are needed to shield against gamma radiation. Protective clothing provides little shielding from gamma and x radiation, but will prevent contamination of the skin with the gamma emitting radioactive material.
Neutrons. Neutrons also penetrate most materials. They are able to travel many feet in concrete and thousands of feet in air. Thick layers of materials with lots of hydrogen in them (like water or concrete) are needed to shield against neutron radiation. Protective clothing provides no shielding from neutron radiation. Neutrons are not likely to be encountered except in the initial seconds of a nuclear criticality event.
Neutrons
Stopped by a few feet of concrete

41. Occupational exposure
Aircrew
Dental worker
Radiologist
Reactor worker
Electron microscopist
Industrial radiographer
Plasma torch operators
High-voltage TV repairman
Underground Uranium miner
Atomic power plant worker

42. Radiation Effects Mutation Chromosome aberrations Cytotoxic effects
Effects on tissues and organs
Cancer

43. Acute Expoture Prodromal stage Latent period,
Stage of manifest illness,
Recovery

44. Acute Radiation Syndrome Spectrum of Disease

45. Hematopoietic ARS Dose: 2-10 Sv Illness: 2-3 weeks after prodromal
Signs and symptoms:
Leukopenia, Thrombocytopenia, Anemia

46. Intestinal ARS Dose: 10-20 Sv Illness: 2-3 days after prodromal
Signs and symptoms:
abdominal pain, fever, diarrhea, dehydration

47. Pulmonary ARS Dose: 6-10 Sv Illness: 1-3 months after prodromal
Signs and symptoms:
Acute pneumonitis, pulmonary fibrosis, cor pulmonale

48. Cerebral ARS Dose: more than 50 Sv
Illness: X minutes to X hours after prodromal
Signs and symptoms:
confusion, ataxia, convulsion, coma, death

49. Skin
Reproductive system
Eye

50. Delayed effects of radiation
Radiodermatitis
Endarteritis obliterans
Intestinal stenosis
Pulmonary fibrosis
Cataract
Cancer

51. Cancers due to irradiation
Leukemia (exc. CLL)
Breast cancer
Thyroid tumors (Papillary adenoma and carcinoma)
Bone tumors
Liver carcinoma
Lung cancer

52. Vibration

53. 8-10 million workers in the USA exposed to occupational vibration.
Of these 7 million: Whole Body Vibration.
Others: Hand Arm Vibration.

54. Truck drivers & heavy equipment operators:
Lumbar spinal disorders
Hemorrhoids
Hernia
GI problems
Urinary tract problems
Result of extended sitting+ vibration

55. Resonance (amplification):
Vibration of the same frequency .
WBV: 5 Hz

56. WBV: <20 HZ
Critical :3-5 Hz Discomfort:2-11 Hz
Musculoskeletal, neurologic, circulatory, and digestive system disorders.
Visual performance impairment: 10-25Hz

57. LBP ,intervertebral disc damage, spinal degeneration, intervertebral osteochondrosis, calcification of discs. Reproductive effects: SAB, congenital malformation, menstrual changes.

58. Vibration sickness:
GI problems, decreased visual acuity, labyrintine disorders, intense musculoskeletal pain.

59. Vibration induced white finger (HAVS)

60. Hand Arm Vibration Syndrome(HAVS)
Ranging from Hz
Usually Hz
Cumulative Trauma: at least 2000 hours and usually over 8000 hours.

61. HAVS:
Spasm of digital arteries (raynaud phenomenon):
Damage of :
Peripheral nerve
Vascular tissue
Subcutaneous tissue
Bones
joints

62. Pathology:
Arterial muscle wall hypertrophy
Demyelinating peripheral neuropathy
Connective tissue deposition
Micro vascular occlusion

63. Clinical findings:

64. symptoms:
Tingling then numbness then white finger in cold.
Intermittent blanching of tip of one finger.
Progress to tip and base of all fingers.
Progress to summer season.

65. Advanced cases: Degeneration of bone & cartilage resulting: Joint stiffness, restriction of motion, arthralgia. Manual dexterity may decrease. Clumsiness may increase.

66. Diagnosis:
Exposure history & response to cold.
Exclusion of idiopathic Raynaud disease & other causes of Raynaud phenomenon.

67. Other causes of Raynaud phenomenon:
Trauma
Frostbite
Occlusive vascular disease
Connective tissue disorders
Neurogenic disorders
Drug intoxication
Vinyl chloride monomer

68. Prevention:
Engineering Controls
Wearing gloves
Keep the hands warm
Prevent long period of exposures
Training
Avoidance from:
Vasoactive drugs & cigarette smoking

70. Pre-employment & periodic examination
Work history with special emphasis on present or past use of vibrating tools during work or hobby activities
Medical history: peripheral vascular, peripheral neural, musculoskeletal complaints
Physical examination: with special attention to peripheral vascular, peripheral neural integrity, muscle force, grip strength
Drugs,alcohol,smoke

71. Physical Examination peripheral neural status:
Light tough
Temperature, pain
Two-point discrimination
Depth perception
peripheral vascular status
Finger blood flow response to cold

72. Physical Examination
Present of CTS, tennis elbow, or other work-related cumulative trauma disorder of the hand or arm
Old injuries that could peripheral vascular or neural signs and symptoms
Primary Raynaud disease

73. Treatment:
Removal from exposure
Massaging, shaking, placing in warm water
For intractable episodes:
Nifedipin 30-40mg/day
Thymoxamine
For more sever cases:
Stanozolol
PGE
Biofeedback & surgical sympathectomy