Lesson 5 Physical factors

Lesson 5.1: Physical factors - Vibration

  • Not going too much into the scientific physics details, vibration can be described as a rapid motion back and forth or from side to side.
  • It can occur while operating tools and machines, such as chainsaws, polishing machines, drills, where vibrations come from elements of those machines moving quickly and generating tremble.
  • As a municipal workers you may encounter such hazard during work at removing trees with chainsaws , or cleaning or polishing pavements or floors using hand-operated polishing machines.
  • At your work, you may be exposed either to vibration transmitted to your hands and arms (hand-arm vibration, HAV), or to your whole body (whole body vibration, WBV).
  • Cardiovascular system
  • Nervous system
  • Musculo-skeletal system
  • Even internal organs, like gastrointestinal tract.
  • Hand-Arm Vibration Syndrome (HAVS), including carpal tunnel syndrome and vibration induced white finger (VWF).
    • Carpal tunnel syndrome is a condition in which the nerves in the wrist are damaged and may results in pain, tingling, numbness and weakness of the hand or wrist. In vibration white finger, the circulatory system is affecter and results also in numbness, tingling and whitening appearance to the fingers. The symptoms may become more severe in cold and wet weather.
  • Whole body vibration may lead to fatigue, stomach problems, headache, loss of balance and “shakiness” shortly after or during exposure. There are studies that revealed connection between WBV and circulatory, bowel, respiratory, muscular and back disorders in truck drivers. There is strong scientific evidence that long exposure to WBV is associated with low back pain.

Lesson 5.2: Physical factors - Noise

  • Noise can be characterized as all unpleasant, unwanted, onerous or harmful vibrations of material medium transferred through air and affecting hearing and other senses of human body. Or simply – loud, undesired, disturbing sound. The impact of noise on human health is twofold:
    • Impact on hearing sense organs
    • Impact on other parts of body
  • The most obvious impact of noise is of course on hearing sense organs.
  • Noise can damage your anatomical structures responsible for hearing resulting in noise induced hearing loss of different level (up to complete hearing loss and deafness). This often happens in case of single events of short time exposure to noise generating high peak acoustic pressure levels, resulting in damages in eardrum leading to acute acoustic trauma.
  • Another possible health effect is hearing impairment without visible damages to hearing organs. This is often a result of a long term exposure to noise of specific intensity, leading to overstrain of hearing sense organs. This effect can be either permanent or temporary.
  • Long term exposure to noise may also be a reason of tinnitus. It is perceived as ringing, hissing or booming sensation in your ears.
  • Because neural hearing path is anatomically connected with human’s brain structures, it can impact the central nervous system and consequently – endocrine system. In general, noise, as a stressor, can induce a systemic response of your organism to stress, which can be reflected in increased breathing frequency, increased heart rate and blood pressure, decreased intestine peristalsis.
  • Apart from obvious health effects, due to character of this hazard, noise may lead to accidents. In noisy conditions workers may have problems with communication, they may not hear each other, they may misunderstand given signals, they can be simply distracted. Furthermore, noise may mask signs of possible danger or warning signs given by machines or alarm installations.

Lesson 5.3: Physical factors – Electric current

  • Although risk arising from exposure to electric current may not be a most frequent one among cleaners, it is nevertheless a hazard that you may encounter in your work. For example, during cleaning you may accidentally touch exposed wires or while operating electric appliances you may experience malfunction of equipment or circumstances leading to electric shock (e.g. touching plugs with wet hands). Furthermore, you may be at risk of fire lit by malfunction of electric installation or poisoning with substances used in electric installations or being a product of fire.
  • As a result of an electric shock, you may experience thermal burns, muscle contractions, leading to e.g. fall from a ladder, or even death due to disrupted heart electrical conduction.

Lesson 5.4: Physical factors - Radiation (including ionizing radiation)

  • Optical radiation:
    • Visible light (VIS)
    • Ultraviolet radiation (UV)
    • Infrared radiation (IR)
    • Laser radiation
  • Ionising radiation
  • Visible light, generally speaking, is this kind of radiation, that can be seen by human’s eye. It’s sources can be natural (the Sun) or artificial (different types of light emitting devices (e.g. incandescent light bulbs, halogen lamps, light emitting diodes, arc lamps, etc.).
  • Although visible light should be considered a very useful in your work, simply allowing you to see what you are doing, there are some circumstances when it creates some threats. They are related to visual perception of human’s eye. What is harmful is for example sudden, big change of brilliance, which may result even in damage of retina. Another example of threat is frequent changes in brilliance, which can be observed when you move your sight from a dark to bright object and do it frequently. Third example is glare – problems with vision due to presence of bright light in field of vision, e.g. direct or reflected sunlight, or very bright lamps.
  • While working outside, you may be exposed to direct sunlight, which is a source of a whole spectrum of radiation, not only visible light, but also ultraviolet and infrared radiation.
  • Ultraviolet radiation has harmful effects on exposed skin and eyes.
  • The most frequent symptom of UV irradiation is erythema visible a few hours after exposure.
  • Numerous and prolonged exposure to UV may result in faster skin aging, changes of skin pigmentation (e.g. freckles, nevi) and dry skin.
  • More serious consequences include skin neoplasms and damage to eyes (retina and conjunctiva).
  • Apart from sunlight, UV may be generated artificially in special lamps.
  • They may be used for sterilization of surfaces and you may encounter them in you work as a cleaner inside buildings.
  • Infrared radiation impacts human body through skin and eyes.
  • The health threat results from the effect IR has on tissue, which is increase of temperature.
  • There are temperature receptors located in skin, which can warn you when the temperature is too high and may be dangerous, however eyes are not so well protected.
  • The most common consequence of exposure to IR is suffering from cataract – cloudy area in the lens of an eye which decreases vision.
  • Exposure to laser radiation is the least likely from optical radiation to occur in your work as cleaner, thus we will just mention here that it may be harmful to your eyes, particularly retina. It can also affect your skin, causing erythema, burn or even charring.
  • Although ionising radiation is typically connected to totally different branches of economy and is present in common understanding in different environment than cleaning activities, it is worthy noticing that also workers who are doing cleaning jobs and work with waste disposal may be exposed to ionising radiation.
  • The radiological accidents in Samut Prakarn (Thailand) and Goiânia (Brasil) are just two examples of what can happen when radioactive source are not handled properly.
  • In both cases radioactive sources were stolen or collected by unauthorised individuals and later they were sold to scrapyards.
  • As a result, several people severely suffered from the effects of ionising radiation developing radiation sickness.
  • That is why paying attention to keeping up to standards of work, respecting procedures and carefully observing your working environment is very important from the workplace safety point of view.

Lesson 5.4: Physical factors - Radiation (including ionizing radiation)

  • During your work as cleaner you are often performing your duties outside buildings or sometimes inside building with special climate.
  • In hot summers you experience high temperatures and direct sunlight, in winters you may be exposed to very low temperatures, windy conditions and moisture in the air.
  • Thus, simply saying, you may be exposed to:
    • Hot environment
    • Cold environment
  • Prolonged time of working in those onerous conditions may cause some serious health issues.
  • Normally, human organism sustains stable body temperature and has physiological capacity to keep the thermal homeostasis.
  • Homeostasis is a term that describes capacity of living organism to maintain stable conditions inside the organism.
  • The most beneficial conditions of microclimate in which humans feel comfortable and well, and processes inside the body run in the most effective manner, are described as thermal comfort. In other words, thermal comfort is the condition in which you are satisfied with thermal environment.
  • Heat stroke. This is the most serious condition. In heat stroke, the body temperature rises, sweating mechanism does not function properly and the body cannot be cooled down. It can cause disability or death.
  • Heat exhaustion. It is a condition caused by significant loss of water and salt due to excessive sweating.
  • Rhabdomyolysis. This condition is related with heat and prolonged physical activity (exertion). It causes destruction of muscle structures, which results in releasing electrolytes and proteins into blood and may lead to irregular heart rate, seizures of kidney malfunction.
  • Heat syncope. This includes fainting or dizziness episodes among workers who work in standing position or with low physical activity in hot environment conditions.
  • Heat cramps. These are related with excessive sweating, leading to loos of body salt and its deficiency in muscles, resulting in painful cramps.
  • Heat rash. In hot environment, body produces large amounts of sweat, which resided on skin and may cause skin irritation.
  • Cold environment is the one in which temperature exceeds below the thermal comfort zone. There are also other factors which may affect your temperature perception. They include air humidity, wind speed, physical activity, work/rest schedule, and of course clothing. At any temperature, the perception of cold is greater when wind blows harder. This effect is called wind chill temperature.
  • Cold-related health conditions you may experience due to exposure to cold working environment include:
    • Frostnip and frostbite. These are skin injuries occurring in exposure to low temperature causing freezing of skin. They may have different severity depending on the time of exposure and experienced temperature. The most commonly affected areas include fingers, toes, nose, cheeks, chin and nose, sometimes hands and feet.
    • Hypothermia. This is a state of drop in body temperature below a certain limit, due to prolonged exposure to low temperature. Symptoms may differ depending on severity, and include shivering, mental confusion, loss of muscle control, hallucinations.