Exposure to forceful exertions and vibration in a foundry

This paper describes the results of a study that investigated the exposure of workers in a foundry to vibration and related physical stresses. The primary objective of this research was to show that use of vibrating tools in the foundry involves exposure not only to vibration, but also to physical stresses both while the tool is running and while it is not running. Four types of tools were investigated: (1) small handheld grinders, (2) scaling hammers, (3) inline hammers, and (4) chipping hammers. The paper describes the characteristics of these tools with respect to physical work factors such as muscle load, upper extremity posture, hand repetition, and exposure to hand/arm vibration. The analysis is based on the use of instrumentation as well as the use of observational methods to quantify the physical work elements. With the exception of the grinders, all the tools investigated in this study produced vibration levels that limited their time of acceptable use, according to published guidelines. In addition to vibration exposure, workers experienced high peak muscle loading, medium to high levels of hand repetition, and extreme or awkward posture of the elbow and shoulder. All tools met or exceeded published recommendation limits for hand activity level.