Week 4: Chapter 5 : Physical Agents

Noise; Early Warning Change

-A deterioration of hearing in the upper frequency —the earliest detectable sign of noise-induced hearing los

Thermal Stress

-Cold and hot temperature extremes coupled with high humidity -Homeostasis (or thermal homeostasis). (veins moving closer and away from skin surface)

non-ionizing radiation

-Electromagnetic radiation that does not have energies great enough to ionize matter Eg. UV radiatoin White Light Radiation Infrared Radiation Microwave Radiation Radio Waves >Sun can be a source of all these radiatio >Control of non-ionizing radiation exposures usually includes isolation or separation, protective equipment, and training

Heat-related Illnesses 2 levels of heat stroke?

-Heat edema -Heat rash -heat cramps -heat stroke Calsical heat stroke Exertional heat Stroke

Vibration Health Effects

-Inhibition of muscular reflexes -Impaired or blurred vision -Alterations of brain electrical activity -Sore neck and shoulder muscle -Sore joint -Raynaud's phenomenon, or white fingers, caused by restricted blood circulation in the finger -Neuritis and degenerative alterations of central nervous syste -Fragmentation -Necrosis (tissue death) -Decalcification of carpal bones -Muscle Atrophy

Radiation What are the 2 types?

-Ionizing Radiation -Non-Ionizing radation

Physical Agents

-Sources of energy that may cause injury or disease -Each of these agents may be ambient or acute (i.e., resulting from a single exposure) -Physical Agents Include: •Radiation •Noise •Vibration •Thermal Stres

Vasoconstriction? Hyperreflexia?

-The process of causing a constriction of the blood vessel -The condition of unusually quick reaction by the nerves to some external stimulus

How can conductive hearing loss be caused?

-caused by wax buildup, infection, or trauma.

Indications of exposure to excessive noise levels:

-ringing in ear (tinnitus) -Raising volume on radio or television

Risk factors for cold-related illnesses

Age, gender, fatigue, diseases, health conditions, consuming drugs or alcohol, smokin Thermal stress is measured using the wet bulb globe temperature (WBGT) index 20-29 HUMIDEX = comfortable 30-39 some discomfort 40-45 great discomfort, avoid exertion 46+ dangerous, heat stroke possible

What does ambient mean?

All-encompassing condition associated with a given environment Composite of inputs from sources all around us

Noise Threshold of hearing Hearing response conditional on three characteristics:

Any unwanted sound -Standards for measurement: decibel (d Threshold of hearing -Range of sound that human ear can perceive or hear Hearing response conditional on three characteristics: -Frequency -Duration -Loudness

Methods of Heat Transfer in the Body

Conduction >When two surfaces are in contact (e.g., the skin touches a hot stove, resulting in a local burn) Convection >When one surface adds heat to the surroundings (e.g., the skin is close to air flow emanating from a heat) Radiation >When energy is transmitted by electromagnetic waves (e.g., the skin is exposed to sunlight

Ionizing radiation Examples? How to control?

Electromagnetic energy capable of producing ions through interaction with matter -X-rays -Gamma rays, alpha particles, beta particles, and neutrons (found in nuclear operations or rsearch companies) To Control: -regular monitoring -shielding -job rotation -protective equipment and -extensive trainin

Whats HAVS?

HAVS is a progressive disorder and is also known as Raynaud's phenomenon that affects the blood circulation in the fingers and toes. CCOHS uses the Stockholm Workshop Classification system to rate vibration-induced conditions. This classification system evaluates sensorineural and vascular impacts separately. Prevention efforts focus on reducing vibration, using ergonomically designed tools, keeping hands warm and dry, and taking rest break

What 2 categories vibration classified in?

Low frequency and High Frequency

Noise Control

Noise Exposure Standards >Vary across provinces and territories Noise exposure test equipment >Sound Pressure Level Meter Octave Band Analyzer >Measures noise level in each frequency range Audiometer >Instrument used to determine sensitivity of a person's hearing

Vibration? What is Resonance?

Oscillating motion of body moving about a reference position resonance: The effect that occurs when an object reacts strongly to some particular frequency

Types of Hearing Loss CONDUCTIVE VS. SENSORINEURAL TTS, PTS

Physiological Damage that affects hearing 1. Conductive Hearing Loss > Restricts transmission of sound to cochlea or inner ear 2. Sensorineural Hearing Loss (nerve Deafness) >Affects the cochlea and is usually irreversible Temporary Threshold Shift (TTS) -Gradual loss -Can someitmes be reversed by removal from noise source Permanent Threshold Shift (PTS) -Hearing disability that is permanent and may not be correctable

Segmented vs Wholebody

Segmented vibration -Vibrations that affect only parts of the body Whole-body vibration -Vibrations that affect the whole body as a unit

Noise can be controlled using the Source-Path-Human Strategies.

Source >Make source quieter Path >Move worker away from source and/or erect sound barriers between noise and work >As the distance from the sound source is doubled, the noise level will drop by a fixed amout Attenuated: >Reduction of noise at one location compared with another farther from the source Human: >PPE >Least Costly most common >not always best method