NIOSHTIC-2 Publications Search

Extended Workdays and Behavioral, Physiologic and Subjective Testing of Underground Gold Miners.

Proc 1990 :139-145
The U.S. Bureau of Mines, the Canadian federal mining and natural resource utilization organization (energy, mines and resources Canada), the Ontario Ministry of Labour, and an underground gold mining operation in Ontario cooperated in a research effort to determine if performance changes and, therefore, safety decrements occur when switching from an 8-h, 3-shift-per-day operation to a 10- h, 2-shift-per-day operation. Concerns have been raised in industry that reduced job efficiency and safety and health hazards attributable to cumulative fatigue arise due to an extended shift schedule. Computerized test stations were set up underground within the mine to measure the test performance of miners throughout the workday during the two different shift schedules. These tests included a choice reaction time task, a time estimation task, a finger tapping task, a tracking task, an addition task with a memory load, and subjective self-evaluation of mood and sleepiness. Preliminary data analysis has determined that statistically significant differences in performances occur dependent upon whether the individual is working 8-h or 10-h shifts. Those on 8-h shifts (1) had more math trials and a higher percentage of math trials correct, (2) had faster, more consistent, and more accurate reaction, (3) had more consistent time estimation, (4) had better tracking scores, and (5) reported feeling less sleepy and grouchy than those on 10-h shifts. Those on 10-h shifts (1) had faster finger tapping scores, (2) had better time estimation, and (3) reported feeling better on six subjective v
Publication Date
Document Type
Fiscal Year
Identifying No.
OP 98-90
Source Name
Proc. 1990 Natl Symp. on Mining, Univ. Kentucky, PP. 139-145
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division