Seasonal and geographical variation of solar UV radiation
| Autor: | Minoru Fukuda, Masako Naganuma, Eiichio Yagi, Eijiro Hara |
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| Rok vydání: | 1991 |
| Předmět: | |
| Zdroj: | Journal of Society of Cosmetic Chemists of Japan. 25:15-20 |
| ISSN: | 1884-4146 0387-5253 |
| Popis: | Ultraviolet (UV) radiation in sunlight is known to play an important role in cutaneous aging. Solar UV radiation doses irradiated onto a horizontal surface at 9 cities (Naha, Miyazaki, Osaka, Yokohama, Matsumoto, Akita, Asahikawa in Japan: Milano in Italy: Taipei in Taiwan) were measured continuously for 2-9 years, using an Integrating Actinorecorder (Suga Test Instruments, Co., Ltd.).Japanese MED (minimum erythema dose) from sunlight was measured on healthy 89 Japanese in order to discuss skin damages by UV rays. The average Japanese MED from 6 runs was 2.2cal/cm2.The mean daily UV doses of 3 cities (Yokohama, Milano, Taipei) were caluculated from the 5 highest daily doses throughout a month. These values were referred to as daily intensity. This daily intensity through one year was generally inversely proportional to latitude. The highest daily intensity was 43.41cal/cm2/day at Taipei, which was 19.7 times dose of Japanese MED.Annual total UV dose was 8320cal/cm2 at Matsumoto, 5663cal/cm2 at Milano and 6965cal/cm2 at Taipei. The highest UV dose in Matsumoto was caused by high altitude and long sunshine hours. Weather affects UV dose, We searched the relation between weather and daily UV dose. UV dose in a cloudy day was 54-73% of a clear day, while that in a rainy day was 16-24%. UV radiation dose was proportional to sunshine hour in each month.The effect of altitude was investigated by measuring UV radiation dose in high regions. In March, UV dose at Lukla (2800m height) was 20% more than that at Taipei (9m height) on the same latitude.Considering the recent worldwide attention towards UV radiation in relation with environmental pollution, it seems extremely important to measure UV radiation in various places of the world. |
| Databáze: | OpenAIRE |
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