Noise Vibration and Thermal Stress Risk

Noise

Excessive noise in the workplace is associated with several negative health outcomes. In the workplace, exposure to excessive noise can be commonplace, but such chronic exposure can have lasting consequences. OSHA (2015) notes that noise exposure is one of the most common occupational hazards, with some 30 million workers being exposed to high noise levels at some point in any given year. The organization's statistics shows that since 2004, 125,000 workers have suffered significant, permanent hearing loss. Short-term effects can also include loss of hearing or diminished hearing and tinnitus. Long-term exposure to high noise levels can result in psychological stress, reduced productivity and reduced communication.. When hearing loss occurs, this increase workplace risk because of the way that hearing loss inhibits concentration, communication and the ability to hear warning signals. The effects of hearing loss are also felt outside of work, making this an overall quality of life issue (OHSA, 2015).

OSHA has set sound limits, as measured in decibels, that are permissible in the workplace. The limits also reflect the time of exposure, because longer exposure creates more damage. In a typical 8-hour day, OSHA limits noise exposure to85 decibels (OSHA, 2015). There are basic devices that are used to measure decibels. In many cases, engineering controls are used to lower the workers exposure to noise. These can include barriers between the noisy equipment and the employee, reducing the sources of noise (such as oiling equipment) and choosing equipment that has noise-reducing features (OSHA, 2015).

Exposure to vibrations are another hazard, related to noise. Physical objects, including bodies, are affected by vibrations. Usually the effects of vibrations are felt over time, with repeated exposure to high vibration levels. Whole body vibration, for example, can result in chronic back pain, and pain in other joints. Vibrations are a contributing factor to the development of carpal tunnel syndrome, which has a negative impact on finger function. Handheld power tools are particularly associated with this type of vibration injury (Brauch, 2015).

Vibration risk is measured in terms of action level, which is 2.5m/s2 HAV or .5m/s2 WBV, two of the measures of vibration commonly used (Brauch, 2015). Older tools will typically have higher vibration levels than new ones, sometimes up to double the vibration, so the rating of a tool when new has to be adjusted for its age. Using relatively new tools is an essential component of reducing vibration risk. There is some debate about how the length of exposure should be worked into the formulae for determining vibration risk, as there is more risk to someone who uses a tool all day compared with someone who uses it occasionally.