To determine effects of the direction of the rotational work shifting on the circadian rhythm and adaptation of physiological and psychological components were investigated with nursing students. Two groups of seven volunteers participated as experimental subjects, and eight nursing students participated as a control group. The directions of rotation work shift were as follows : CW(clockwise)-shift system rotation in the direction of day shift(3 lays), evening shift(3days), off duty(1day) and night shift(5days). and CCW(counterclockwise)-shift system rotation in the reverse direction. Urinary free cortisol and 17-hydroxycorticoster oids in the urine were measured by the solid-phase radioimmunoassay and the colorimetry methods, re spectively. Plasma melatonin was measured by radioimmunoassay. The urinary free cotisol rhythm changed to ir-regular on the evening and night shift in the CCW shift system, whereas the rhythm seems to adapt on night shift in the CW shift system. The daily rhythms of urinary 17-OHCS indicate that they are well synchronized to shift work. These results show that the rotation of shift in the CW direction is more acceptable in terms of the adaptation of hormonal rhythms. These results indicate that the CCW rotation of shift work makes it more difficult for the workers to adapt on a physiological level, and has many more negative effects on nurses when compared with the CW rotation. Thus, a clockwise rotating shift systern seems to be more desirable for the optimal health and performance of nurses.

In this study, 20 students in C university were selected by control group and 14 shift work nurses working in C university hospital by test group It took part in case of day shift(8AM-4PM), evening shift(4PM-12MN), and night shift(12MN-8AM) to know a urinary 17-OHCS and free cortisol changes which works in a rapidly rotating shift work system. The working team were an rest period of a day and an oberservation of an week. It obtained an urine specimen before and after work shift in 2nd day. Test group and control group of shift work compared to change of levels of urinary 17-OHCS and free cortisol of urine collected from nurses of day shift, evening shift, and night shift. The data was analyzed by t-test, paired t-test. The results are as follows. 1. Compare 8AM with 4PM in day shift. Control group increased 4.1mg at 8AM, 4.2mg at 4PM in a case of 17-OHCS(p=.84) and also test group increased a little 3.5mg at start time of work, 3.6mg at stop time(p=.97). In a case of free cortisol control group decreased 3.8microgram at 8AM, 2.4microgram at 4PM(p=.12) and test group decreased 8.3microgramat start time of work, 3.2microgram at stop time(p=.22). 2. Compare 4PM with 12MN in evening shift. Control group decreased 4.2mg at 4PM, 2.9mg at 12MN in a case 17-OHCS(p=.54), but test group increased 1.7mgat start time of work, 3.4mg at stop time(p=.07). In a case of free cortisol control group decreased 2.4microgram at 4PM, 1.9microgram AT 12MN(p=.23) and also test group decreased a little 2.6microgram at start time of work, 1microgram at stop time(p=.43). 3. Compared 12MN with 8AM in night shift. Control group increased 3.9mg at 12MN, 4.1mg at 8AM in a case of 17-OHCS(p=.79) and also test group increased 6.3mg at start time of work, 8.4mg at stop time(p=.16). In a case of free cortisol control group increased 1.9microgram at 12MN, 3.8microgram at 8AM(p=.08) and test group increased 4.4microgram at start time of work, 11.6microgram at stop time(p=.04). As a result of this study reveals that health level of nurses is decreased in a rotating shift work(2 days internal). As mentioned above, it was confirmed that the rotating shift work had influence on the health of the nurse. For it, I present the objective base data to measure the level healthy in order to extend the understanding of the physical aspects of the nurses. Moreover, it is considered that one can make use of it as an objective base data with a view to the rational management for the nursing administration.