Health benefits of solar UV-B radiation: Cancer risk reduction

Based on geographical distributions of various cancers in the U.S. and elsewhere, ecologic studies comparing these distributions to indices of solar radiation during the past 20 years have led to the understanding that solar UV-B radiation is a risk reduction factor for breast, colon, ovarian, prostate cancer and non-Hodgkin's lymphoma (NHL). Photo-initiated production of vitamin D is the mechanism that enables solar UV-B to play this role. The work presented here explores the use of the USDA UVB Radiation Monitoring Program ground station values to confirm and extend the prior results, and compares these results to those obtained using UV-B data from the Total Ozone Mapping Spectrometer (TOMS). Inverse correlations between solar UV-B radiation have been found for a total of 14 cancers using mortality data from the U.S. with these data sets, and are supported by additional studies using cancer mortality and dietary supply data from Europe. While vitamin D has been shown to be a risk reduction factor for several of these cancers, it is hoped that additional studies will be conducted to confirm or disprove the protective role of UV-B and/or vitamin D for the remaining cancers.