The influence of dose rate on ultraviolet tumorigenesis

J Photochem Photobiol B. 1991 Jul;10(1-2):41-50. doi: 10.1016/1011-1344(91)80210-9.

Abstract

To gain an insight into the relationship between the time in which a daily UV dose is delivered and its carcinogenic effectiveness, the following experiment was performed. Three groups of 24 albino hairless mice (Skh-hr1) were exposed to the same daily dose of UVB radiation (600 J m-2; Philips TL12). The exposure times for the three groups were 1.25, 4 and 12 h per day. A fourth unirradiated group served as a control. All animals exposed to UVB developed multiple skin tumours, whereas the control animals did not develop any observable tumours. Tumour development in the groups exposed for 4 and 12 h was virtually identical. Tumour development was significantly faster in the groups exposed for 4 and 12 h per day than in the group exposed for 1.25 h: the median tumour induction time was reduced by 12%. In terms of the effective dose, this is equivalent to a 25% increase in effectiveness for the 4 and 12 h groups relative to the 1.25 h group. In conclusion, the present experiment shows that prolongation of the exposure duration increases the carcinogenic efficacy of UVB radiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dose-Response Relationship, Radiation
  • Mice
  • Mice, Hairless
  • Neoplasms, Radiation-Induced / pathology
  • Neoplasms, Radiation-Induced / physiopathology*
  • Reference Values
  • Skin Neoplasms / etiology
  • Skin Neoplasms / pathology
  • Skin Neoplasms / physiopathology*
  • Time Factors
  • Ultraviolet Rays*