title: Diurnal variations in solar ultraviolet radiation at typical anatomical sites.
abstract: OBJECTIVE
  Solar ultraviolet (UV) radiation is an important environmental factor that affects human health. The understanding of diurnal variations of UV radiation at anatomical sites may be helpful in developing ways to protect humans from the harmful effects of UV radiation.
  
  
  METHODS
  In order to characterize the diurnal variations, the UV exposure values were measured at 30 min intervals by using Solar-UV Sensors and a rotating manikin in Shenyang city of China (41 degrees 51'N, 123 degrees 27'E). Measurement data for four representative days (in each of the four seasons respectively) were analyzed.
  
  
  RESULTS
  The diurnal variations in solar UV radiation at the shoulder, the forehead and the chest were similar to those associated with a horizontal control measurement. However, the diurnal variations at the eye and the cheek exhibited bimodal distributions with two peaks in spring, summer and autumn, and a unimodal distribution in winter. The UV exposure peaks at the eye and the cheek were measured at solar elevation angles (SEA) of about 30 degrees and 40 degrees , respectively.
  
  
  CONCLUSIONS
  The protection of some anatomical sites such as the eye from high UV exposure should not be focused solely on the periods before and after noon, especially in the places and seasons with high SEA.
authors: Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, China.
authors: Li-Wen
authors: LW
authors: Hu
authors: Qian
authors: Q
authors: Gao
authors: Wen-Ying
authors: WY
authors: Xu
authors: Yang
authors: Y
authors: Wang
authors: Hui-Zhi
authors: HZ
authors: Gong
authors: Guo-Qing
authors: GQ
authors: Dong
authors: Jing-Hai
authors: JH
authors: Li
authors: Yang
authors: Y
authors: Liu
mesh_terms: D002940:Circadian Rhythm; D014466:Ultraviolet Rays