ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

3pNS1. Investigation of the impact of changes in regulatory criteria on the daily noise dose (DND) of longwall coal mine workers.

J. Alton Burks

Roy C. Bartholomae

U.S. Bureau of Mines, Pittsburgh Res. Ctr., Pittsburgh, PA 15236

The authors previously examined the impact of anticipated changes in noise regulations on the coal mining industry [R. C. Bartholomae and J. A. Burks, Noise-Con 94, 1017--1022 (1994)]. That analysis focused primarily on assessing the effect on the daily noise dose (DND) resulting from changing the current threshold level from 90 to 80 dBA. To more fully explore the effect of other regulatory parameters, as well as the threshold level, 59 sets of full-shift time-resolved dosimeter data were acquired on four occupations associated with longwall coal mining. After these data were downloaded to a computer, realistic combinations (a total of 12) of criterion level (80, 85, 90 dBA), threshold level (80, 85, 90 dBA), and tradeoff rate (3, 5 dBA) were applied to these data to compute DND's. The results of this ``what if'' type analysis are presented. In general it was concluded that the magnitude of the computed DND resulting from changes in either the tradeoff rate or the threshold level is unpredictable; instead, it depends on the specific distribution of noise levels associated with a given worker's noise exposure.