Envionmental Electromagnetic Fields and Experimental Studies on Their Bioeffects
Masateru IKEHATA, Takao KOANA, Masayoshi NAKAGAWA
We have many chances for environmental and clinical exposure to static, high frequency or
extremely low frequency (ELF) magnetic fields (MF) from power lines, cellular phones, magnetic
resonance imaging (MRI) and electrified transportation systems. It is necessary to consider
whether exposure to MF causes adverse health effects in human bodies.
In this paper, we present some preliminary results of measurements of EMF from several
appliances and make discussions comparing with present regulations. We also tried to detect
mutagenic effect of MF on bacterial genome. Strong static MF (5T) and 50 Hz time-varying MFs
(0 to 40 mT) were tested for their mutagenic potential in bacterial mutation assay (Ames' Test)
using Salmonella typhimurium and Escherichia coli. For the tested MFs, no mutagenic properties
were revealed under the present test conditions. However, in the co-exposure study with some
chemical mutagens, the frequency of revertant colony was slightly inclined to be affected. These
results suggest that MF affects chemical reaction in biological system, and it is possible to
have co-mutagenic activity. However, this effect was very weak and statistically non-significant
and it is not probable that MF is a severe environmental hazard.