Abstract

OBJECTIVES--To evaluate lorry drivers' work stress by measurement of adrenaline and noradrenaline excreted in the urine, and to find out which factors in their working situation are related to the excretion rates of these catecholamines. METHODS--The urinary excretion of adrenaline and noradrenaline of 32 lorry drivers, who also had loading and unloading activities to perform, was studied for one working day and one rest day. Each driver was asked to provide six urine samples on both days. RESULTS--For all samples, except the first (overnight) sample, the excretion rates of both catecholamines on the working day were higher than those on the rest day. Hierarchical multiple regression analyses were carried out to find out which factors in the drivers' working situation were related to the excretion rate of the working day. The excretion rate of adrenaline on the rest day, age, and psychosomatic complaints were positively related to the excretion rate on the working day (all P < 0.05). Body mass index and physical workload during loading and unloading were positively related to noradrenaline excretion rate (both P < 0.01). Psychosocial job strain did not significantly contribute to the proportion of variance explained in the excretion rates of both catecholamines. CONCLUSIONS--The excretion rates of adrenaline and, especially, noradrenaline on the working day were higher than those found in earlier studies among professional drivers and insufficient recovery took place after the work was ended. The only association between excretion rate on the working day and work stressors was found for noradrenaline and physical workload. The drivers' sympathoadrenal medullary reactivity to everyday work demands shows the characteristics of sustained activation.