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Physical Hazard. Dr. Ardini Raksanagara, MD., MPH Public Health Department Faculty of Medicine, UNPAD. SPECIFIC LEARNING OBJECTIVES . The student will be able : to identify physical hazards in the workplace environment (C2) . References.
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Physical Hazard Dr. Ardini Raksanagara, MD., MPH Public Health Department Faculty of Medicine, UNPAD
SPECIFIC LEARNING OBJECTIVES The student will be able : to identify physical hazards in the workplace environment (C2)
References • Suma’mur, Higene Perusahaan dan Kesehatan Kerja, CV Haji Masagung, Jakarta, 1994 Hal. 57-101 • Joseph LaDou J, ed. Occupational and Environmental Medicine, 2nd edition. Stamford: Appleton & Lange, 2004. Chapter : 11. • Levy & Wegman, Occupational Health, Recognizing and Preventing Work Related Disease. Third Edition. Little Broan and Company, Boston / NewYork/Toronto/London,2006. Chapter :16
Introduction • Physical exposures that occur over time can cause human illness • Physical exposures are widespread in industry, in nature, and in various community and medical setting : • noise, vibration, thermal stress, • electromagnetic radiation, • Increased or decreased pressure
The underlying science the explores measurements and intervention to reduce physical hazards exposure is based in physics • The study of the relationship between energy and matter
Type of Physical Hazards • Temperature • Pressure • Noise • Illumination • Vibration • Radiation * electric and magnetic fields
Temperature(Extremes Temperature) 1. Heat -lassitude, irritability, discomfort -lowered work performance lack of concentration lack of judgment loss of critical thinking skills - skin disorders : heat rashes -heat cramps -heat exhaustion -heat stroke
2. Hypothermia - Chilblains, - Immersion Foot, - Frostbite
Occupational Heat Stress • There are an estimated 5 to 10 million in industries where heat stress is a potential safety and health hazards • On average, approximately 400 people die each year in the US from exposures to excessive heat in work, home, and community setting
Heat related occupational illness, injuries and strain occur in any situation where total heat load ( environmental heat plus heat generated by the body’s metabolism) • The major modes of heat exchange between workers and their environment are : convection, conduction, radiation , evaporation
Prevention • Acclimatization • Measuring environmental temperature • Assessing metabolic work rates
2. Pressure 1. Hyperbaric -Tympanic membrane rupture - Pneumothorax - Air embolism - DCS (Decompression Sickness) 2. Hypobaric - Acute Mountain Sickness (AMS) - High Altitude Pulmonary Edema(HAPE)
Hyperbaric • Hyperbaric environment are most commonly encountered in a diving setting , • any situation in which compressed air is required underwater tunneling • Exposure to increased atmospheric pressure (under water) leads to aseptic bone necrosis around the knee, hip and shoulder which can be detected by X ray examination
Hyperbaric health problem • Barotrauma • Middle ear trauma • Pulmonary overinflation syndrome pneumothorax mediastinal emphysema arterial gas embolism
The most common health problem occurring in hyperbaric environment is known as BAROTRAUMA • Which involves an imbalance in pressure of air cavities and sinuses within the body as they are subjected to an acute change in pressure
A classic example is Middle ear barotrauma • In which a pressure imbalance develops auma and between the middle ear and the external ear canal causing tympanic membrane trauma and acute ear pain
A related but more serious form of barotrauma is known as Pulmonary overinflation syndrome • In which the lungs become overinflation due to expansion of the air within them during ascent
This overinflation can reach a breaking point at which alveolar capillaeries rupture, leading to • Pneumothorax • Mediastinal emphysema • Arterial gas embolism
Prevention Hyperbaric • Managing time spent at depth • Carefully controlling the rate of descent and ascent
Arterial gas embolism, resulting from the introduction of compressed air into the bloodstream, • Has various neurologic manifestation • Confusion • Weakness • Stroke • Loss of consciousness
Hypobaric • Hypobaric environment are commonly encountered by those in high altitude mountain setting, pilot and passengers in unpressurized aircraft
At altitude greater than 2500m, the partial pressure of oxygen becomes significantly reduced and altitude related illness can be begin to occur • Especially in those who have not acclimatized because of ascending too rapidly
Acute Mountain Sickness • The most common form of altitude illness • an imbalance between hypoxic induced cerebral vasodilatation and hypocarbia induced cerebral vasoconstriction • Is characterized by • Headache, nausea, vomiting, fatigue, loss appetite
3. Noise Definition • Unwanted sound • Unwanted,irregular,unpleasant and annoying sound
Impairment to hearing is produced by excessive exposure to noise as well as to ototoxic chemicals • Effect of noise : damage of hearing organ physiological effects • Potential damaging effects of noise are not uniform at all frequencies • Exposure to high levels of noise can also have other adverse physiological effects
Criteria for exposure and measurements of hazardous noise measured in decibels • In terms of human factors of hearing, the amplitude of pressure is stated in decibels (dB) related to properties of human perception of loudness
Noise exposure can be measured and quantified in units of pressure in relation to units of time
Noise Noise induced hearing loss can be detected by audiometry Noise induced hearing loss is cumulative Exposure outside the workplace can result in hearing impairment not predictable by workplace monitoring alone. non occupational exposure ?
Noise Induced Hearing Loss • Acoustic Trauma • Temporary Threshold Shift (TTS) • Permanent Threshold Shift (PTS)
Occupational Noise Regulation • Engineering control • Administrative control • Use of hearing protective devices (HPDs) • Ear muff • Ear plug
Engineering controls for Noise • Reduce noise emitted by individual sources such as modifying machines or enclosing sources with acoustical shielding • Specify limits on noise emission for new acquisitions or replacement of sources • Acoustically shield • Install acoustic absorbers • Place partial barriers between noise sources and workers
Hearing Protective Device Factors contributing to reduced performance • Worker discomfort • Worker’s reluctance to wear them for a full work shift • The tendency to remove HPD to readjust or clean, leading to incorrect positioning
To achieve maximum protection, HPDs must be correctly fitted and installed • Not simple task • Workers must motivated to use the correctly
The basic instrument for survey is the sound level meter (SLM)
4. Radiation • Ionizing Radiation • Non-ionizing Radiation
Terminology related to Radiation • The most important concepts to understand in the field of radiation are • Ionizing and non ionizing radiation • Exposure and dose • Half-life and activity • risk
Health effects of Radiation • Vary with • The type • Amount, and • Duration of exposure
When radiation exposes a cell, it may • Pass through without doing any damage • Interact and damage the cell, with later repair by the cell • Interact and damage the cell in such a way that it continues to reproduce itself in a damaged state • Kill the cell
The death of single cell may not be harmful, but if many cells are killed within an organ then that organ may not function properly
Ionizing Radiation 1. Electromagnetic - x-rays - gamma rays 2. Particulate - electrons - protons - neutrons
Non-ionizing Radiation • Ultraviolet • Infrared • Microwave • Laser radiation
Type of Radiation Injury Irradiation can cause many types of effect on the human body, depending on the dose and the condition of exposure • Mutagenic effect • Carcinogenic effect • Teratogenic effect ! : Radiation Sickness
Prevention and Protection from radiation • Engineering controls eliminate or reduce the potential exposures at the source Exp. Interlocks, shielding, bonding, grounding and filtering • Administrative control Increasing the distance between the source and the worker, controlling the duration of exposure, restricting access, placing warning signs
5. Vibration • Is a complex physical exposure, which lends itself to electro-physical measurement
Vibration cause vascular disorders of the arms and bony changes in the small bone of the wrist • Vascular changes are difficult to detect. • Test are complicated and non specific • Bony changes can be detected by x ray examination • The most common finding is rarefaction of the lunate bone
Type of vibration : • Whole body vibration • Segmental vibration health effects are usually related to energy transfer to the upper extremity
Segmental vibration (hand-arm) • Vibration effects on the peripheral nerves and small vessels of the upper extremity from hand • There are variety tool types and qualities of exposure that are associated with vibration related upper extremity disorders.