Combined effects of working environmental conditions in VDT work

Abstract

The combined effects of city noise and luminance of the computer display were evaluated from the changes in lymphocytes and mental activities of participants. Healthy male students were tested under the following four experimental conditions: (1) a calculating task on a video display terminal (VDT) with luminance of 90 cd m(-2) without city noise; (2) a calculating task on a VDT with luminance of 20 cd m(-2) without city noise; (3) a calculating task on a VDT with luminance of 90 cd m(-2) with city noise of 70 dB(A); and (4) a calculating task on a VDT with luminance of 20 cd m(-2) with city noise of 70 dB(A). A visual reaction test (VRT) was performed, and critical flicker fusion frequency (CFF), heart rate (HR), numbers of circulating white blood cells (WBCs), lymphocyte subsets and subjective symptoms of fatigue were measured (1) before; (2) just after; and (3) 30 min after each 60 min test. Subjective symptoms of fatigue significantly increased just after experiments conducted under the two noisy conditions. VRT and CFF showed significant changes in the case of the high-luminance display with noise. WBCs and neutrophils showed significant increases in the two quiet conditions. These results suggested that high luminance with noise had the most effect on subjective fatigue and mental activities.

Multiscale entropy approach to physiological fatigue during long‐term Web browsing

“…The mean HR is approximately 76 beats per minute (bpm) during the first half hour of the browsing task, and it monotonically decreases with browsing time. This decreasing trend agrees with the findings of previous VDT studies (Higuchi et al, 2003;Takahashi et al, 2001). The mean HR reaches a minimum of 68 bpm at 4 to 4.5 hours.…”

“…Uncomfortable symptoms arising from video display terminal (VDT) tasks may include visual fatigue (Bergqvist & Knave, 1994;Sheedy, 1992) and musculoskeletal complaints (Li & Buckle, 1999), and much research on VDT tasks has been reported. Questionnaires have been widely used to investigate psychological fatigue during VDT tasks (Dillon & Emurian, 1995;Dillon, Kleinman, Choi, & Bias, 2005;Duffy & Chan, 2002;Stüdeli & Menozzi, 2003), whereas other studies have gathered physiological signals by electroencephalography (Shieh, Chen, & Wang, 2005), electromyography (Balci & Aghazadeh, 2004;Murata, Uetake, Matsumoto, & Takasawa, 2003;Park, Kim, & Shin, 2000;Seghers, Jochen, & Spaepen, 2003), and critical flicker fusion (Chi & Lin, 1998;Takahashi et al, 2001) to measure physiological fatigue. Heart rate (HR) has been measured in VDT tasks at low load levels (Higuchi, Motohashi, Liu, Ahara, & Kaneko, 2003;Takahashi et al, 2001); however, the change in HR is not remarkable when it is compared with the high loading task like HR recovery after exhausted exercise (Du et al, 2005;Platisa, Mazic, Nestorovic, & Gal, 2008).…”

Stress Characteristics in Different Work Conditions: Is it Possible to Identify Specificity of Risk Factors by the Questionnaire Method?

“…Many studies regard this type of workers. The possible sources of stress and mental fatigue for these workers are identified in workplace features, such as microclimate, noise and ergonomic factors (11), organizational factors such as repetitiveness, monotony of tasks, dissatisfaction, excessive sedentariness, prolonged time in using YOU and low possibility of human relations (8)(9)(10)(11)(12)(13). For these factors, a correlation with an increase in aesthenopia and musculoskeletal symptoms is also demonstrated (9-10, 12-13).…”

Effect of Overtime Work and Insufficient Sleep on Postural Sway in Information‐Technology Workers

“…The critical flicker fusion frequency (CFF) test is a suitable method for the measurement of short-term visual strain 5,6) , however, few studies have indicated that CFF is sensitive as an objective measure of chronic fatigue. Therefore other convenient tools are required to detect exhausted workers at risk.…”