Objectives This study aimed to evaluate job stress and changes in salivary amylase (sAMY) activity as an indicator of stress reactions among Japanese emergency medical technicians (EMTs), and to examine the effect of job stress on sAMY while EMTs perform their duties.
Methods Seventy-four male Japanese EMTs of the X City Fire Bureau were divided into three groups according to job class: team leaders, team members, and drivers. We employed the Japanese version of the National Institute for Occupational Safety and Health Generic Job Stress Questionnaire and measured pre- and post-shift levels of sAMY using a hand-held monitor.
Results The three groups reported different levels of job stress. Leaders had lower sAMY levels post-shift than pre-shift. In drivers only, there was a significant positive correlation between sAMY levels and the cognitive demand stressor category (r＝0.612, P＜0.01); however, there was a significant negative correlation between sAMY and social support from supervisors (r＝－0.466, P＜0.05) and social support from coworkers (r＝－0.494, P＜0.05).
Conclusions The task of driving an ambulance car constituted a cognitive demand for drivers, perhaps because it required their full concentration. This job stressor was associated with a corresponding post-shift increase in sAMY; moreover, social support in the workplace was important for reducing stress-induced elevated sAMY in drivers. In team leaders, who experienced heavy psychological strain and job responsibilities, the lower post-shift sAMY levels may be associated with suppression of the sympathetic nervous system when they are freed from the psychological strain and sense of responsibility.