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| Sound levels around 8 horizontal vibrating screens |
Background
Engineering noise controls are being developed and tested to reduce the noise generated by horizontal vibrating screens used in coal preparation plants. These screens are among the equipment used in preparation plants that generate the highest sound levels. A NIOSH cross-sectional survey project indicated that 20 out of 46 surveyed coal preparation plant workers (43.5%) had noise exposures exceeding MSHA’s permissible exposure level (PEL). Based on the cross-sectional survey and MSHA data, it appears that more than 3,400 coal preparation plant workers are overexposed to noise across the country.
NIOSH is working with mining companies and vibrating screen manufacturers to evaluate various controls for reducing noise related to the screens. Measurements taken by NIOSH showed that the sound levels around a group of eight horizontal vibrating screens ranged from 94 to 98 dB(A). The goal of this project is to develop engineering noise controls that will reduce sound levels by 10 dB(A).
Potential Outcome
Research on engineering noise controls for horizontal vibrating screens will be completed in 2008. To raise industry awareness of the engineering noise controls developed, results will be disseminated through publications in journals and trade magazines and also presentations at technical conferences and industry briefings related to noise exposure in the mining industry. In addition, an informational DVD/CD that summarizes the development and safety benefits of the developed engineering noise controls will be produced. This DVD/CD will target vibrating screen manufacturers and industries that use vibrating screens. This work has the potential to eliminate noise overexposures for approximately 3,400 coal preparation plant workers. It is anticipated that 43% of the coal preparation plant workers could be affected by 2009.