PERFORMANCE AND ALERTNESS ON 8 H AND 12 H ROTATING SHIFTS AT A NATURAL-GAS UTILITY

An 8 h/5-7 day shift schedule was compared with a newly instituted 12 h/2-4 day schedule in this, our second worksite study of extended work shifts. Workers completed a performance/alertness test battery, and a questionnaire on sleep patterns and other personal habits, 2-4 times a week on all shifts. After 10 months adaptation to the 12 h shift sche dule, there were decrements in performance/alertness attributable to t he extra 4 h on the extended shift. There were also reductions in slee p across the workweek which were most apparent on 12 h night shifts. T he results are consistent with our first worksite study of 12 h shifts and indicate extra caution should be exercised when scheduling critic al activities for extended workshifts, especially extended night shift s.