Today, we’re discussing an important topic that often goes unnoticed but can significantly impact worker health: exposure to vibration. Whether working with heavy machinery, driving for long hours, or even using power tools at home, understanding the effects of vibration on the body is crucial.
In this post, we’ll explore the health risks associated with prolonged exposure to vibration and how it can affect worker health and well-being. We’ll discuss the types of vibrations you might encounter, the symptoms to watch out for, and practical steps you can take to minimize the risks. Being aware and proactive can protect yourself and ensure a healthier, safer environment.
What You’ll Learn
- Types of Vibration Exposure: Understand the different types of vibration and where you might encounter them in your daily life or work.
- Health Risks and Symptoms: Learn about the potential health effects of vibration exposure and how to recognize the early signs of vibration-related conditions.
- Preventive Measures: Discover effective strategies and practical tips to reduce your exposure to vibration and protect your health.
Introduction
Vibration can be explained in three forms: sinusoidal, periodic, and random. Sinusoidal motion occurs when an item is displaced from a neutral point to a positive or negative direction. As the velocity of the wave increases and then decreases, the particle accelerates and decelerates. Therefore, the amplitude of acceleration is used to measure vibration.
Periodic vibration is repeated sinusoidal vibrations, occurring simultaneously with their own amplitude and frequency. Random vibration occurs when the vibration does not repeat itself. Instead, it consists of a variety of frequencies at varying intensities. To determine the overall acceleration of random vibration, each constituent vibration is analyzed according to its frequencies, and an average root mean square acceleration is obtained for each frequency.
Sources of Vibration
Some sources of vibration in the industrial environment include:
- Pneumatic machinery or tools such as jackhammers and pneumatic chisels
- Heavy vehicles such as long haul trucks, tractors, and underground mining vehicles
- Vibrating floors from a large processing plant
- Motorcycle handlebars
- Mowers, shearers, and gardening hedge clippers
- Hand-held tools such as drills, sanders, polishers, and grinders.
From these examples of vibration-generating sources, it can be seen that the critical physical property of vibration is the relationship between the item’s mass and stiffness. A source of sinusoidal vibration is the mass-spring system. In an idealized system, the mass can move only vertically, with the frequency at which the system moves dependent on its natural frequency. The natural frequency is the frequency a system will vibrate at when excited randomly.
From an industrial hygiene perspective, if the vibrating system’s damping is effective enough, its natural frequency becomes zero. This means that after a disturbance, the system returns to its equilibrium position without oscillation.
Health Effects of Exposure to Vibration
The health effects of exposure to vibration can be categorized according to its intensity and frequency (Karjnak, 2018). At high-intensity vibration levels, the body organs are battered at relatively low frequencies (e.g., heavy vehicles driving over uneven and bumpy ground).
Vibrational intensities at the lower scale are suspected of causing back fatigue, leading to degenerative changes. Whole-body vibration is the term used to describe this form of vibration. In addition to the degenerative effects on the spine, whole-body vibration can also affect vision since the image presented to the retina is unstable.
Whole-body vibration (Marin et al., 2017) occurs when the vibrational energy is between 1 Hz and 80 Hz. The body has a whole-body resonance, around 5 Hz, for vertical vibration. When seated, the vibrational resonance occurs at two frequencies: 5 Hz and about 10-12 Hz. The significant effects can be categorized as comfort-related, health-related, and performance-related.
Frequency-dependent effects occur mainly at high frequencies, for instance, when using powered hand tools such as drills, grinders, pneumatic hammers, chisels, and sanders. The vibration damages the blood and nerve supply to the fingers and hands (Löfgren et al., 2020), leading to a temporary loss of muscle control and white blanching of the fingers.
These symptoms are known as vibration white finger or Raynaud’s disease. They are further exacerbated by cold and wet conditions. Other soft-tissue injury symptoms, such as inflammation of the nerve, muscles, or connective tissue, including carpal tunnel syndrome (Vihlborg et al., 2017), are also associated with exposure to vibration. The bones of the hand or arm are also prone to damage.
Exposure to vibration also affects comfort. For instance, frequencies of 0.1-0.63 are associated with motion sickness. Vibration can also affect the ability to perform writing, reading, and eating tasks.
Summary
Vibration is a physical factor that acts on the human body by transmitting mechanical energy from oscillation sources. The health effects from exposure to vibration typically occur to the whole body (when sitting or standing) or local vibration that acts through the hands and arms.
Helpful Resources
- Human Aspects of Occupational Vibration, by D.E. Wasserman
- Hand-Arm Vibration Syndrome, by Nerys Williams
- My LinkedIn Post on Health, Safety, and Well-Being
Bibliography
Karjnak, K. (2018). Health effects associated with occupational exposure to hand-arm or whole body vibration. Journal of Toxicology and Environmental Health, 21(5), 320-334. https://www.tandfonline.com/doi/abs/10.1080/10937404.2018.1557576
Löfgren, A., Vihlborg, P., Fornander, L., Bryngelsson, I.-L., & Graff, P. (2020). Nerve Function Impairment After Acute Vibration Exposure. Journal of Occupational and Environmental Medicine, 62(2), 124-129. https://journals.lww.com/joem/FullText/2020/02000/Nerve_Function_Impairment_After_Acute_Vibration.5.aspx
Marin, L., Rodriguez, A., Rey-Becerra, E., Piedrahita, H., Barrero, L., Dennerlein, J., & Johnson, P. (2017). Assessment of Whole-Body Vibration Exposure in Mining Earth-moving Equipment and Other Vehicles Used in Surface Mining. Annals of Work Exposures and Health, 61(6), 669-680. https://doi.org/10.1093/annweh/wxx043
Vihlborg, P., Bryngelsson, I.-L., Lindgren, B., Gunnarsson, L. G., & Graff, P. (2017). Association between vibration exposure and hand-arm vibration symptoms in a Swedish mechanical industry. International Journal of Industrial Ergonomics, 62(November), 77-81. https://www.sciencedirect.com/science/article/pii/S0169814117300951
