Circadian rhythms in some groups of Indians working in shifts.

The present study was undertaken in order to find out the effect of changes of shifts on different physiological responses in Indian industrial workers. Two groups, one of 8 workers from industries and another of 6 sedentary subjects used as controls, acted as volunteers in this study. The first group worked in three different shift rotations: morning, afternoon and night. The second group worked in two shifts: day and night only. Different physiological responses, specially the pulse rate and oral temperature, were recorded hourly. The other physiological responses, such as frequency of micturition, gastro-intestinal disturbances, hours of sleep were also noted. Several days of consecutive work and recreational activities were considered in each subject. In the control group, the oral temperature rhythm did not change significantly with the change of shifts; so did the pulse rate rhythm. But this group had less sleep and higher frequency of micturition in the night shift routine than those during day shift. The typical industrial workers' oral temperature rhythm also did not change significantly with the shift changes, but their pulse rate rhythm changed slightly with shift change, possibly in an attempt to adapt. They generally slept well in all 3 shifts and had micturition equally frequent. However, there were individual variations with some peculiarities in both the groups.