Physiological Reaction and Manual Performance during Work in Cold Storages

Abstract

Subjects were 10 workers (Group R) working in two cold storages (air temperature was between -20°C and -23.2°C ), and eight workers (Group C) working in a general storehouse (air temperature was between 12°C and 15.2°C ). They were all male workers operating forklift-trucks . Average (SE) age for Group R was 41. 4(1.3) years and for Group C was 47.3(1.6) years. Hand tremor, handgrip strength, pinch strength, counting task, flicker value, peak flow rate and blood pressure were measured five times (before work, at 10 a.m., before lunch, at 3 p.m. and after work) per day. Blood samples were collected before lunch. Free fatty acid (FFA) of Group R was significantly higher than that of Group C. There were no significant diffcrences in handgrip strength, pinch strength, counting task, flicker value and peak flow rate between Group R and Group C. However, changes in hand tremor and diastolic blood pressure for Group R were significantly greater than those for Group C. Only for Group R, there was a significant relationship between FFA and the hand tremor values measured the second time. Work loads of Group R would be increased by not only the extreme coldness but also large tempera-ture difference between the inside and the outside of the cold storages. The actual forklift work in these cold storages did not cause a distinct reduction in manual performance, but caused an increase in stress which would be expressed as an increase in catecholamine excretion.