Is a differentiated advice by season and region necessary?

David H. Sliney, Stephen Wengraitis

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


The ultraviolet radiation component in the solar spectrum varies greatly with season. In the summer, the significant short-wavelength (UV-B) radiation at midday can produce erythema in sensitive skin in less than 20 min in middle latitudes, and yet in winter months, the same midday exposure dose would require hours of exposure. The challenge for public health authorities is to provide simple, understandable messages for sensitive individuals to limit excessive exposure at appropriate times of the day during spring and summer months and yet not to take needless precautions or limit exposure during fall and winter months at mid and circumpolar latitudes. The appropriate exposure for beneficial effects is not possible to achieve at many latitudes during winter months, but is readily achieved in summer months. Simple messages should be tailored to the local times of day, reflecting the locale and season. One simple means to communicate the relative UV-B exposure relates to the length of one's shadow (the "Shadow Rule"). Further challenges are presented when apparently mixed messages would be justified for different skin phototypes.

Original languageEnglish (US)
Pages (from-to)150-160
Number of pages11
JournalProgress in Biophysics and Molecular Biology
Issue number1
StatePublished - Sep 2006
Externally publishedYes


  • Seasonal
  • Sunlight
  • Ultraviolet
  • Vitamin D

ASJC Scopus subject areas

  • Molecular Biology
  • Biophysics


Dive into the research topics of 'Is a differentiated advice by season and region necessary?'. Together they form a unique fingerprint.

Cite this