WORK STRESS AND RECOVERY MEASURED BY URINARY CATECHOLAMINES AND CORTISOL EXCRETION IN LONG-DISTANCE COACH DRIVERS

Objectives-To evaluate coach drivers' work stress during work and in t he course of recovery from work by measurement of urinary catecholamin es and cortisol.Methods-The urinary excretion rate of adrenaline, nora drenaline, and cortisol of 10 coach drivers was studied during a long distance trip of three days and two consecutive days off. Each driver was asked to provide seven urine samples on the working days and six u rine samples on the days off. The second day off was considered as the baseline. Results-An occupationally induced disturbance of the circad ian rhythmicity was found for adrenaline and noradrenaline but not for cortisol. The mean excretion rates of adrenaline on the first working day and most samples on all working days were higher than the baselin e. For both adrenaline and noradrenaline the mean excretion rates on t he first day off were lower than the baseline. For cortisol, the mean excretion rate on all working days was higher than the baseline. A tre nd towards accumulation of cortisol excretion from the first working d ay to the third working day was found. A backward shift in peak concen trations was found for adrenaline and noradrenaline on the second work ing day, as was a forward shift in peak concentration of cortisol on b oth days off. Conclusions-Long distance coach drivers showed occupatio nally induced reactivity in rates of urinary excretion of adrenaline, noradrenaline, and cortisol. After the outward journey the rates of ex cretion of catecholamines did not return to baseline values. The cours e of recovery in adrenaline excretion after the journey showed a new p henomenon, which has been called ''fatigue debt''. it is recommended t hat longer resting times in shuttle bus trips and fixed days off after these kind of trips should be planned. Extensive future research shou ld be focused on the additional relations between fatigue debt and hea lth complaints.