Health And Safety Implications Of Diurnal Variability In Tolerance To Stress.
NIOSH 1983:209 pages
Productivity of female workers was measured to study circadian variations in human efficiency and work capacity. Sixty three Yugoslav workers (mean age, 24.4) with an average of 4.1 years of work experience were studied during three shifts in an electronics facility. Performance efficiency in various tasks, and physiological and psychological variables were measured in a laboratory setting to assess differences in circadian variations. The relationships between personality factors and circadian variations during a vigilance task were also measured. The greatest differences in worker efficiency were on Monday or Tuesday, with significant decreases among night workers. From Wednesday on, differences were no longer significant. The most efficient shift was the afternoon shift; the night shift was the least efficient. Subjects with greater family responsibilities slept less than those who had none. For reaction time tasks, reaction times were longest on Tuesday for afternoon and night shifts and on Mondays for the morning shift. Reaction times were shortest during the last 2 days of the work week. Introversion and extraversion were not related to circadian phases. Personality factors had no significant effects on dependent variables. The author concludes that there are periods when workers are susceptible to accidents due to performance decrements from disrupted circadian rhythms.
Clinical-symptoms; Work-performance; Physiological-response; Work-capability; Physiological-testing; Sleep-deprivation; Occupational-exposure; Clinical-diagnosis; Physiological-measurements;
NTIS Accession No.
Division of Biomedical and Behavioral Science, NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio, 209 pages, 50 references