PNNL

Abstract

In line with the possible relationship between electric power and breast cancer risk as well as the underlying "melatonin hypothesis", 50-Hertz MF exposure at uTesla flux densities for either 13 or 27 weeks was found to significantly increase the development and growth of mammary tumors in a series of experiments from Loscher's group in Germany, using the DMBA model of breast cancer in Sprague-Dawley rats. This finding could not be replicated when a similar experimental protocol was used in a study conducted by Battelle in the U.S.A. In the present paper, investigators from the two groups discuss differences between their studies which might explain the apparent discrepancies between the results. These differences include the use of different substrains of Sprague-Dawley rats, with the U.S.A. rats being more susceptible to DMBA than the European rats, different sources for diet and DMBA, differences in environmental conditions, and differences in MF expossure metrics. Furthermore, in view of the fact that the effects of MF exposure reported by Loscher's group, albeit significant, were weak, the general problem of replicating such weak effects is discussed.