Re your question on sanet about the effects of electromagnetic
fields (EMF) on people and crops. As you may be aware, EMF issues
are in the news most recently because of a paper in the International
Journal of Radiation Biology (mid-February 1996 issue). In the
paper, the authors speculate about a link between radon daughters
influenced by electric fields and certain cancers. However, they also
state in their abstract "at present, there still remains no
persuasive biological evidence that power frequency electromagentic
fields can influence any of the accepted stages in carcinogenesis."
There is a news item in the 15 February issue of Nature from which
I took most of the above information.
As far as I can tell, the issue of EMF's effect, if any, on cancer
(I haven't heard about mental or emotional effects) is still very
much up in the air. A paper in last year's Nature (Vol 375, p 23)
reported a failure to reproduce one of the most highly publicized
possible links, an increase in transcription of a gene involved
with carcinogenesis, but there have been several reports of the
connection. The Nature paper contains a number of references,
and might be a useful place to start your research, but even
the experts seem confused at the moment.
Of relevance to the issue of growing and working on crops under
power lines, most or all of the effects that have been reported
are seen at the limits of detection. It may be that the level
of exposure of a person who works in the fields (both agronomic
and electromagnetic) seasonally and sleeps away from the field
is low enough to be of little concern. As for the crops, I have
always wondered why no one seems to have looked at the effects
of EMF on plants such as trees that live for extended lengths
of time and many generations under very high voltage long distance
power transmission lines. As far as I know, this is still
an open study area. Back to the radon issue: the title of
the Int. J. Rad. Biol. paper is "Enhanced deposition of radon
daughter nuclei in the vicinity of power frequency magnetic
fields." Apparently it has long been known that EMF causes
radon daughters to stick to surfaces. So there may be a chance that,
_in areas of high levels of soil radon_, radon decay products
might be deposited on crop plant surfaces. In areas of low
radon levels this would not be a concern, of course.
Hope this helps,
Steve Verhey
Department of Crop and Soil Science
Washington State University
Pullman WA 99164-6420