Occupational Health and Safety: Test 2 with complete verified solutions 2024

Scaffolding Incident Example The Scaffolding on the swing-stage of Metron Construction had only two lifelines available for seven men and only one was using the fall protection. Five men fell to the ground when the stage broke, four does instantly and the other left permanently disabled. Physical hazard Typically entails a transfer of energy that results in injury T/F: Noise and vibration are considered physical hazards True What is the most common physical injury? Contact with and object/machine or falls Latent failures Conditions that elect substandard or unsafe behaviours that are present in the system without causing immediate threats but have the potential of being a step in an injury event Examples of latent failures workplace design, organization of work, management decisions, environmental conditions T/F: most injury prevention efforts are focused on the employer False: They are focused on the employee Noise Sound energy that moves through the medium of the air. It consists of small air pressure changes caused by vibration of the molecules 3 Characteristics of noise 1. Frequency 2. Duration 3. Loudness Frequency Vibration of the medium through which sound energy moves How is frequency measured? Hertz (Hz) which is the number of vibrations/second We can normally hear sounds with frequencies between ___HZ and ___Hz Between 20Hz and 20 000Hz Duration The length of time a worker is exposed to noise Loudness The amount of energy that is being carried through the medium What is the key feature of Decibels? They are a logarithmic scale, each increase on a logarithmic scale is an order of magnitude. At 10dB the sound is 10x more intense, at 20dB it is 100x more intense Noise over ___dB is considered hazerdous for human hearing Over 85dB Temporary theshold shift The normal range of human hearing has been reduced. It usually reverses itself over a short period of time. It is a signal that noise exposure was harmful and long exposure could result in permanent hearing loss Permeant threshold shift Extended exposure to noise hazards leads to permanent hearing loss T/F: Women have higher rates of permanent threshold shift False: Men do possibly due to men working in louder workplace environments than women T/F: Extended exposure to noise hazards can lead to non-hearing health effects True Non-hearing health effects associated with exposure to noise Startled response to sound, changes in endocrine and biochemical systems, nausea, headaches, and constricted blood vessels Acoustic trauma Caused by short, intense exposure to noise, usually of a high frequency Call centre example of acoustic trauma When working in a call centre the sudden high frequency noise emitted from the headset are over 100dB, the acoustic trauma is caused by sudden high frequency rather than the dB level. There is a rapid increase in instances of acoustic drama in call centres because of this. Time-weighted average An exposure model that factors duration and loudness Short comings to regulating noise exposure 1. Regulations do not adequately address the health effects of short, intense, and high frequency sounds 2. Insufficient evidence to determine if 85dB every day over 8 hours is safe. 3. The rules do not account for individual vibration Vibration The oscillating movement of a particle around i stationary reference position 2 types of workplace vibration 1. Whole-body vibration 2. Segmental vibration Whole-body vibration When a workers entire body experiences shaking caused by contact with vibration; most common with low-frequency vibration ex. driving in a car Segmental vibration Occurs when only parts of the body are affected by vibration; usually caused by higher-frequency vibration Controlling noise and vibration at the source Elimination, substitution, and engineering controls Controlling noise and vibration at the pathway Erecting sound barriers, installing vibration resistant material on tools Thermal stress When temperature extremes prevent our bodies from self-regulating Thermal comfort The condition in which a person wearing normal clothing feels neither too cold or too warm 3 concepts of thermal comfort 1. Temperature 2. Humidity 3. Air movement ACGIH recommends that work cease completely at temperatures between ___degrees C and ___ degrees C depending on wind chill and at temperatures over ___degrees C Between -32 and -43 Over +30 Radiation Any energy emitted from a source including heat, light, X-Rays, microwaves 2 forms of radiation 1. Ionizing - Radiation with enough strength to remove electrons from a molecule as it passes through causing the molecule to become positively charged. 2. Non-Ionizing - Unable to ionize molecules but have other effects ex. microwaves, UV An exposure as low as ___rem of radiation will significantly increase the risk of cancer 10rem Annuel limit for workers exposed to ionizing radiation 2rem Elliot lake walk out example Workers were struck over high levels of radiation exposure and it was one of Canada's first health and safety related walkouts Ergonomics The study of how workers and the work environment interact Job design Compromises the decisions employers make about what tasks will be performed by the workers and how it will be performed A core principle of ergonomics Fit the job to the worker not the worker to the job Why are workers more reluctant to address ergonomic issues? The required changes affect the workplace process or may impede managements ability to direct work What is the best way to address ergonomic hazards? Engineering controls Fracking example Fracking is a process in which workers drill deep holes and inject fluid and 4000000gallons of chemicals at a high pressure into the ground to crack the rock layer. 75% of the chemicals used in this negatively affect the body and it endangers both the workers and the public Chemical hazard A substance that causes harm to human tissues or interferes with normal physical functioning 4 routes of entry for a chemical 1. Respiration