Shigeyuki Ogawa,Masanori Okada
Septem Soken Co.,Ltd．Japan
Makoto Yamashita (Presenter) ,Tomoko Wakamura,Manami Saito,Rina Omomo,Syunsuke Nagashima
Kyoto University,Japan
Kanako Muramatsu,Morihiro Yoneda
Nara Women's University,Japan
Tadashi Oishi
Nara Saho College、Japan

[ Abstract]
Previous research reported that the solar exposure for short term influenced immunological function ,skin temperature and fatigue sensation (Hyun 2005; Wakamura 2005).
This study was performed to examine how the exposure to natural solar radiation including ultraviolet could influence the mental work performance.
Twenty male participants (range: 19-26, mean age: 22.2 years old) showing skin type Ⅱ (Sato, 1992) were randomly divided into two groups which were “UV-exposure group” (EXP-group) and “UV-protect group” (PRO-group) with clothing.
They stayed outside between 11:30 to 14:30 (accumulated UVB: 8.93kJ/m2, UVA: 773kJ/m2, amount of global solar radiation: 9.36MJ/m2).
Kyoto University Graduate School and Faculty of Medicine approved the experimental protocol. All participants were informed of the potential risks and gave their voluntary written consent. Two groups were analyzed by using a two-way analysis of variance (ANOVA) with repeated measures.

Discussion during the experiment from 11:30 to 14:30,
1.Change of skin color (ΔE) in the PRO-group was significantly lower than EXP-group (p<0.01).
2.Participants in EXP-group sensed significantly higher fatigue (the questionnaire by Japan Society for Occupational Health) compared with PRO-group after solar exposure (p<0.05).
3.On the mental work test, the amount of reduction in the performance, due to the solar exposure, was not different between the two groups with the exception of the direct ratio.
4.The plasma cortisol level was decreased in the PRO-group, whereas this was maintained in the EXP-group (p<0.1).